Massage, Traction, and Manipulation

Various forms of massage, traction, and manipulation have been used in medicine throughout the world for several thousand years. Each modality represents an approach to treatment of the musculoskeletal and other systems sought by a steadily increasing number of people, despite a relative dearth of quality, evidence-based research supporting their isolated use. Research on each of these modalities continues, but they are all united by a longstanding variable, the concept of touch.

In the 1940s, Spitz reported on children's home infants who, though otherwise healthy and well cared for, failed to thrive and often died in the absence of being held or touched. Kunz and Krieger additionally defined and taught the principles behind the related concepts of healing and therapeutic touch in the 1970s.

Although there is no consensus on the complete physiology of massage, traction, or manipulation, it is generally accepted that these treatment approaches involve more than just the interaction of mechanical forces and human anatomy. There is a long history of touch as a natural, essential component to healing and health maintenance.

Each of these treatments has some scientific support to back its use in certain cases or conditions, and from a logical perspective, one can assume that some middle ground exists for the application of massage, traction, or manipulation in a carefully assessed and controlled manner within the medical paradigm. Each of these treatment approaches also carries some potential risk, but given the estimates of use worldwide and the rare reports of direct or indirect side effects related to these therapies when they are performed correctly and under proper circumstances, the risks appear to be minimal, with the treatments offering potential benefits for patients.

From an osteopathic perspective, manipulation is not intended to be a standalone treatment; rather, it is meant to be a component of the overall treatment strategy for a given patient. Indeed, current research on manipulation seems to support this use, and further research must be done on a variety of conditions to determine the best approach or combination approaches that will most effectively and safely aid the patient’s recovery. The same concept should be applied to the investigation of massage and traction to determine how best to use these treatments in the complete medical care of a patient.

Because physiatry has embraced the “team approach” since its inception, combining the administration of an appropriate thorough history and physical examination with the use of a variety of physician and nonphysician practitioners, manipulative modalities, and treatments is not a new concept. This strategy is well accepted and has been shown to be effective for many types of patients.

Throughout history, massage has been woven into the cultural context of medicine. It may well be the earliest tool used to treat pain. ^[1] Massage consists of Eastern and Western variants.

In the United States, approximately $14.7 billion is spent annually on visits to massage therapists, chiropractors, or acupuncturists; this accounted for nearly half of the $30.2 billion spent on complementary healthcare in 2012. ^[2]

The American people are pursuing massage in increasing numbers for various reasons (eg, relief of pain, relaxation, conditioning). Although there is little doubt that massage is beneficial for certain conditions, additional research is needed to establish its profile of efficacy.

Definition

Massage is the therapeutic manipulation of soft tissues of the body with the goal of achieving normalization of those tissues. Massage can have mechanical, neurologic, psychological, and reflexive effects. Massage can be used to reduce pain or adhesions, promote sedation, mobilize fluids, increase muscular relaxation, and facilitate vasodilation. Massage can easily be a preliminary treatment to manipulation; however, it clearly targets the health of soft tissues, whereas manipulation usually targets joint segments.

Massage consists primarily of hand movements, some of which may be based on traction (defined as the act of drawing or pulling or as the application of a pulling force, either with equipment or manually). The hand movements of massage, like those of traction, are often fairly nonspecific but may be very locally targeted as well.

Forms of massage

Western

Western massage is the chief type of massage practiced in the United States today. Among the most common types of massage therapy are acupressure (shiatsu), Rolfing, Swedish massage, reflexology, and myofascial release. ^[1] Western massage organizes variations of soft-tissue manual therapy into several categories. Pare of France introduced the basic terminology for Western massage to the United States.

The essence of Western massage is use of the hands to apply mechanical forces to the skeletal muscles and skin, though the intent may be to affect either more superficial tissues or deeper ones.

Types of basic Western massage are characterized by whether (1) the focus of pressure is moved by the hands gliding over the skin (ie, effleurage), (2) soft tissue is compressed between the hands or fingers and thumb (ie, pétrissage), (3) the skin or muscle is impacted with repetitive, compressive blows (ie, tapotement), or (4) shearing stresses arecreated attissueinterfaces below the skin (ie, deep friction massage).

Forms of Western massage include the following:

• Effleurage
• Pétrissage
• Tapotement
• Deep friction ^[3]

In effleurage, the practitioner's hands glide across the skin overlying the skeletal muscle being treated. Oil or powder is often incorporated to reduce friction; hand-to-skin contact is maintained throughout the massage strokes. Effleurage can be superficial or deep. Light strokes stimulate cutaneous receptors and act via neuroreflexive or vascular reflexive mechanisms, whereas deep stroke techniques mechanically mobilize fluids in deeper soft-tissue structures. Deep stroking massage is performed in the direction of venous or lymphatic flow, whereas light stroking can be in any direction desired.

Effleurage may be used to gain initial relaxation and patient confidence, occasionally to diagnose muscle spasm and tightness, and to provide contact of the practitioner's hands from one area of the body to another. The main mechanical effect of effleurage is to apply sequential pressure over contiguous soft tissues so that fluid is displaced ahead of the hands as tissue compression is accomplished.

Pétrissage involves compression of underlying skin and muscle between the fingers and thumb of one hand or between two hands. Tissue is squeezed gently as the hands move in a circular motion perpendicular to the direction of compression. The main mechanical effects are compression and subsequent release of soft tissues, reactive blood flow, and neuroreflexive response to that flow.

Lymphatic pump is a type of pétrissage done to the chest and rib cage of persons with respiratory compromise in order to draw lymph into the thoracic duct and venous circulation as a result of an alternating increase and decrease of pressure on the chest cavity.

Tapotement is a percussion-oriented form of massage that involves striking soft tissue with repetitive blows, using both hands in a rhythmic, gentle, and rapid fashion. Numerous variations can be defined by the part of the hands making an impact with the body.

The therapeutic effect of tapotement seems to result from compression of trapped air that occurs on impact. The overall effect of tapotement may be stimulatory; therefore, healthy persons with increased tolerance for this approach are more likely to find this type of massage useful.

In deep friction massage, pressure is applied with the ball of the practitioner's thumb or fingers to the patient's skin and muscle. The main effect of this technique is to apply shear forces to underlying tissues, particularly at the interface between two tissue types (eg, dermis-fascia, fascia-muscle, or muscle-bone). Deep pressure keeps superficial tissues from shearing so that shearing forces are directed at the deeper tissue surface interface. Deep friction massage frequently is used to prevent or slow adhesions of scar tissue.

Eastern

Over the centuries, Eastern massage systems have been an integral part of the cultures where they are practiced. Systems for evaluation, diagnosis, and treatment generally are not grounded in conventional Western neurophysiology. Eastern massage includes, among other approaches, shiatsu, a Japanese system based on traditional Chinese meridian theory with principles of Western science.

The theory of shiatsu is based upon the system of the 12 traditional Chinese meridians (ie, major channels) of the body in which the energy, life force, or chi circulates. Acupressure pressure points, situated along the course of channels, allow access to these channels. Acupressure applies massage forces, largely through digital pressure, to the same points treated with acupuncture needles. Imbalances of energy along the meridians are believed to cause or contribute to disease and can be rectified by localized finger pressure.

Reflexology and auriculotherapy

These systems of massage share the meridian concept with shiatsu. In these approaches, the meridians are believed to have whole body representations on the extremities (similar to the homunculus of the brain). The feet (in reflexology) and the ear (in auriculotherapy) have been mapped in great detail.

Decongestive lymphatic therapy

Decongestive lymphatic therapy is a complex massage approach that includes manual lymphatic drainage (MLD) in addition to compressive bandages, exercises, and skin care; it is most often used in acute and chronic lymphedema. MLD consists of gentle massage in the treatment of lymphedema. Proximal areas are treated first to prevent a damming effect; the treatment is thought to stretch the lymphatic collectors and stimulate the drainage system. The massage is followed by the application of compressive bandages and is incorporated into a complete self-care program.

Effects of massage

Physiologic

Massage produces some mechanical effects on the body. Mechanical pressure on soft tissue displaces fluids. Fluid moves in the direction of lower resistance under the static forces of the practitioner's hands, but a moving locus of pressure creates a pressure gradient. Assuming no significant resistance, pressure is lower proximal to the practitioner's advancing hand. Once mobilized fluid leaves the soft tissues, it enters the low-pressure venous or lymphatic systems.

The amount of fluid mobilized in any single treatment is likely to be small; however, the physiatrist must be aware of this physiologic effect in patients with significantly compromised cardiovascular or renal function. When treating lymphedema, massage is performed more proximally and then moves distally, based upon the premise that proximal blockage in the lymph channels must be opened first to allow for subsequent distal mobilization of fluid and protein.

Kneading and stroking massage decreases edema; compression converts nonpitting to pitting edema. In addition to strictly mechanical effects, these massage approaches release histamine, causing superficial vasodilation to assist in washing out metabolic waste products. Venous return then increases, which subsequently increases stroke volume.

Some evidence suggests that massage increases blood flow contralaterally; however, the mechanism of this postulated action has not been well established. These effects on mobilization of fluids are more important in flaccid or inactivated limbs, because normal compression supplied by skeletal muscle contraction usually is not present in those cases.

Studies suggest that massage may decrease blood viscosity and hematocrit and increase circulating fibrinolytic compounds. Preliminary data suggest an explanation for the success of massage in decreasing deep vein thrombosis (DVT). Massage may be contraindicated in the presence of existing thrombosis.

Other blood compounds that show massage-related increases include myoglobin, creatine kinase, lactate dehydrogenase, and glutamic oxaloacetic transaminase. Temporary increases in these substances represent local muscle cell leakage from applied pressure. Lactate decreases in massaged muscles as well.

Massage may decrease muscle spasm and increase contraction force of skeletal muscle. Decreased spasm and increased endurance may result from wash out of metabolic waste products by fluid mobilization and increased blood flow. Decreased muscle soreness probably results from metabolic washout.

Massage can stimulate cutaneous receptors, spindle receptors, and superficial skeletal muscle as well. These structures produce impulses that reach the spinal cord, producing various effects, including moderation of the facilitated segment. Somatovisceral reflex changes to the viscera are possible in this model.

Psychological

Massage generally increases feelings of relaxation and well-being in patients. Whether this is from the placebo effect or is the result of an as yet unknown reflex is not fully understood. Practitioners often incorporate a variety of psychophysical techniques, such as guided imagery, into massage treatment.

A prospective, nonrandomized trial of massage therapy at a major US cancer center sought to examine massage therapy outcome in a large group of patients. Over a 3-year period, 1290 patients were treated with regular ("Swedish"), light touch, or foot massage, based on the request of the patient. The patients completed symptom cards before and after a 20-minute (average) massage session. Symptom scores were reduced by approximately 50%, with outpatients demonstrating about 10% greater benefit than did inpatients. Anxiety, nausea, depression and pain demonstrated the greatest improvement in symptom score.

Several studies have investigated the role and potential benefits of massage during pregnancy. A study by Field et al found such a benefit not only in the recipient of the massage, but also in the patient's spouse. ^[4] In this study, self-reported leg pain, back pain, depression, anxiety, and anger were reduced to a greater extent in pregnant women who underwent massage than in women in the control group.

In addition, the women's partners, who performed the massages, reported feeling less depression, anxiety, and anger over the course of the massage therapy period than did partners in the control group. ^[4] Moreover, the pregnant women and their partners showed improved scores on a relationship questionnaire. The data support the positive psychological effects of massage and reinforce the therapeutic concept of touch.

Indications

Massage may be used as a primary therapeutic intervention or as an adjunct to other therapeutic approaches and techniques. Such uses can include, but are not limited to, the following:

• Mobilization of intertissue fluids
• Reduction or modification of edema
• Increase of local blood flow
• Decrease of muscle soreness and stiffness
• Moderation of pain
• Facilitation of relaxation
• Prevention or elimination of adhesions

Massage may be used to alter the pathophysiology of a primary condition (eg, contracture) or to prevent or modify deleterious effects of a previously used treatment modality. ^[5]

Many studies have focused on the utility of massage for treating low back pain. ^[6] The authors of one literature review concluded that strong evidence exists for the efficacy of massage in relieving chronic, nonspecific low back pain; they also found "moderate evidence that massage provides short- and longer-term follow-up relief of symptoms." Moreover, the authors determined there to be "moderate evidence that acupressure may be better than Swedish massage" for chronic low back pain, "especially if combined with exercise."

Hospitalized patients who receive massage express improvements in mood, body image, self-esteem, and perceived levels of anxiety. This phenomenon is facilitated by reduction in physical symptoms and distress and may be accompanied by decreased tension, anxiety, and pain perception.

Another therapeutic effect derived from massage is muscle relaxation. Massage appears to reduce tone and enhance circulation to the involved area. Muscle relaxation may also result from increased sensory stimulation caused directly by massage. This increased sensory input to the spinal cord may result in changes in reflex pathways, leading to central modulatory decreases of muscle tone.

Other effects of massage are enkephalin release, endorphin production, promotion or absorption of fibrous tissue, restoration of connective tissue pliability, improvement of lymphatic flow (in some studies, seven- to ninefold), and increased levels of natural killer (NK) cells. Tanabe et al provided animal data suggesting that mechanical stimuli, such as massage, to adipocytes may inhibit expression of adipogenic transcription factor peroxisome proliferator-activated receptor, which is independent of systemic energy consumption. ^[7] They postulated that such stimuli can assist in reducing the body’s fat stores, and may help to decrease stress-related obesity.

Contraindications

Massage is contraindicated when it could cause worsening of a particular condition, unwanted tissue destruction, or spread of disease. Vascular thrombi, atherosclerotic plaques, and infected tissue could be spread by massage. Absolute contraindications for massage include the following:

• DVT (because increased blood flow in a limb could cause a thrombus to detach from the vessel wall, creating an embolism)
• Acute infection
• Bleeding
• New open wound

Relative contraindications include the following:

• Incompletely healed scar tissue
• Fragile skin
• Calcified soft tissue
• Skin grafts
• Atrophic skin
• Inflamed tissue
• Malignancy
• Inflammatory muscle disease
• Pregnancy

The physiatrist should also be aware that massage must be used very carefully in chronic pain patients and those with mental health disorders.

The direct, hands-on nature of massage may potentiate strong psychophysical effects and may cause unintentional reliance on passive treatment modalities. In all patients, it is necessary to establish treatment end points at the outset of the treatment period and to terminate treatment when those end points have been achieved or when their achievement appears unlikely.

A 2003 review by Ernst that examined the safety of massage found that the majority of adverse effects of massage therapy occurred as a consequence of performance by lay practitioners or as a result of using "exotic" massage practices, other than Swedish-style massage. ^[8] He further concluded that whereas massage therapy is not entirely risk-free, reports of serious adverse events appeared to be rare. It would be beneficial for the physiatrist, or other prescribing physician, to be aware of the training and experience of the massage therapist to whom the patient is referred.

The practitioner controls several variables of massage, including the environment in which massage is done. Actual application of treatment includes rhythm, rate, pressure, direction, and duration. ^[9]

Most massage approaches involve a friction-reducing medium, so that the hands of the practitioner move along the patient's skin with minimal friction. Powders or oils often are used. Massage strokes should also be regular and cyclic. The rate of application for massage varies with the type of technique. In some approaches (eg, tapotement, percussion), the rate is several times per second, whereas in others, it is much slower.

The amount of pressure depends upon technique and desired results. Light pressure may produce relaxation and relative sedation and may decrease spasm; breakdown of adhesions and intervention at a deeper tissue level may require heavier pressure. Treatment of edema and stretching of connective tissue generally requires intermediate amounts of pressure. Direction of massage often is centripetal to provide better mobilization of fluids toward the central circulation. The sequence of tissues treated often proceeds in a centripetal fashion.

When muscles are treated, motions are often kept parallel to muscle fibers. If the treatment goal is to reduce adhesions, shearing forces are circular or include at least  cross-fiber components. The area to be treated with massage depends on the condition being treated and may range from a well-circumscribed smaller area to larger or contiguous areas.

Duration of therapy

Duration of treatment depends on the area being treated, the desired therapeutic goals, the diagnosis, the patient's medical stability, and patient tolerance. Wide variation exists regarding treatment duration, which often is guided by changes occurring to tissue during massage application. If massage is performed before other treatments, duration may be determined by the result needed in order to optimize the next treatment step.

The duration of a massage therapy program can range from 1 week to months and depends upon verifiable and specific therapeutic goals. Patients must be reexamined and reassessed from time to time, depending on diagnosis and therapeutic goals, to ensure satisfactory progress and address possible changes to the treatment approach.

Although many studies have been conducted on the clinical utility of massage, the quality of these efforts has been somewhat variable. Several studies have investigated the use of therapeutic massage in conjunction with exercise, acupuncture, or manipulation, particularly in athletic performance, and the reduction of postexercise or delayed-onset muscle soreness. ^[10]

A 2012 Cochrane review of 15 trials assessed whether massage could help reduce neck pain and improve function. ^[11] The authors concluded that no overall recommendations for practice could be made at that time, because the effectiveness of massage for neck pain remained uncertain. As a standalone treatment, massage for neck pain was found to provide immediate or short-term efficacy for both pain and tenderness; however, to assess the long-term effects of treatment, further research was deemed necessary. 

Similar conclusions were reported by numerous other studies, with a common consensus being the need for additional research on the benefits of therapeutic massage. Research studies evaluating massage have had significant variations in sample size and constitution and have suffered from an absence of adequate controls, methodologic errors, and other limitations.

A 2015 Cochrane review of 25 trials including 3096 participants with low back pain (acute in one trial, subacute or chronic in the remainder) found the quality of the evidence to be "low" to "very low," mainly because of risk of bias and imprecision. ^[12] The authors had "very little confidence" that massage is an effective long-term means of treating low back pain. Beneficial effects appeared to be limited to short-term follow-up; adverse effects were noted to be rare and minor.

The long-term efficacy of massage has not been validated. Future inquiry must establish the long-term efficacy of massage in a more rigorous, scientific fashion. Studies are needed that use valid experimental design and allow pretesting and posttesting; these investigations must also employ appropriate sample sizes and statistical analysis methods, include reliable and valid measurement tools, and provide some degree of standardization of duration and frequency of treatment. It is also argued that some attempt to control for the so-called placebo effect (as well as touch) must be included in future studies.

Additional research may examine the effectiveness of massage when it is used in conjunction with one or more other treatments, such as manipulation, exercise, or medications.

Since the days of Hippocrates, correction of scoliosis has involved traction. There are various types of traction currently in clinical use. The most common are as follows:

• Mechanical traction
• Hydraulic or motorized traction
• Manual traction
• Autotraction

Mechanical forms of traction use a hydraulic or motorized pulley system with weights, along with a harness or sling device to attach to the patient’s body. Manual traction involves the practitioner using his or her hands on the patient’s body, with the body weight of the practitioner providing the tractive force. Autotraction is controlled by the patient pulling on bars or handles at the head of the table, without direct involvement of a clinician. Gravitational traction with a tilt table and underwater variations of traction are also in clinical and home use but are less frequently employed than other forms.

Traction has enjoyed a long history of clinical acceptance based on very little scientific understanding of its mechanism of action or efficacy. Two 2005 surveys examined the use of traction by physical therapists. One, by Haarte et al, ^[13] contained data from the United Kingdom, whereas the second, by Poitras et al, ^[14] was performed in Quebec, Canada. Both surveys reported widespread use of traction by physical therapists for the treatment of low back pain. Significant questions exist regarding duration of symptom relief and other possible benefits derived. Given the difficulty of objective documentation of the benefits of traction, it is not surprising that there has been a reduction in its use in recent years.

Definition

Traction is the act of drawing or pulling and relates to forces applied to the body to stretch a given part or to separate two or more parts. Currently, traction is used effectively in treatment of fracture; however, the ensuing discussion will be confined to non-fracture-related use of this modality. In physiatric practice, use of traction often is limited to the cervical or lumbar spine with the goal of relieving pain in, or originating from, those areas. ^[15]

Effects of traction

Traction effects changes in the spinal column itself, with soft tissues only secondarily changed.

In the cervical spine, the most reproducible result of traction is elongation. In a classic study, Cyriax reported applying a force of 300 lb manually, with a resultant 1-cm increase in cumulative lumbar spine interspace distance. ^[16] Studies have shown that optimum weight for cervical traction to accomplish vertebral separation is 25 lb. Additionally, elongation of the cervical spine by 2-20 mm has been shown to be achievable with at least 25 lb of tractive force.

Studies have demonstrated that the anterior intervertebral space shows the most increase in cervical flexion (up to 30°). Traction in the extended position generally is not recommended, because it is often painful and may increase risk of complications from vertebral basilar insufficiency or spinal instability.

Once friction is overcome in the lumbar spine, the major physiologic effect of traction is elongation. Investigators have reported widening of lumbar interspaces requiring between 70 and 300 lb of pull. This widening averaged up to slightly more than 3 mm at one intervertebral level. The length of time that the separation persists remains indeterminate, with studies documenting distraction durations of 10-30 minutes after treatment.

Data on dimensional and pressure changes of lumbar disks caused by traction are not conclusive. Decreases in interdiskal pressure with 50-100 lb of traction have been documented, but evidence exists that some applications cause an increase in interdiskal pressure. Therefore, evidence is inconclusive, with much information favoring at least temporary reduction of the herniated component of an abnormal lumbar disk with concomitant traction.

Some theories on the physiologic effects of traction suggest that stimulation of proprioceptive receptors in the vertebral ligaments and monosegmental muscles may alter or inhibit abnormal neural input from those structures. As with other theories to explain the physiology of traction, there is little to no empiric evidence to fully support it. ^[17]

Indications

The literature does not clearly indicate which types of neck or low back pain may improve from traction. Studies strongly suggest that traction has no significant influence on the long-term outcome of neck pain or low back pain. Practitioners who rely on sound scientific advice may use traction rarely. Practitioners who are receptive to empiric treatments may be amenable to the concept that traction may separate vertebrae and decrease the size of herniated disks, thereby benefiting radiculopathy; however, no consensus has been reached among clinicians or researchers in this area.

In a 2008 review investigating the use of lumbar traction for patients with chronic low back pain, Gay et al found only 10 randomized, controlled trials addressing this treatment. ^[18] As a group, the studies contained more evidence against the use of traction than for it. The authors broke the information into subcategories on the basis of whether the data covered patients with back and lower limb pain or patients with low back pain alone. They also looked at sustained and intermittent traction in these patient groups.

The results indicated a lack of benefit in the use of sustained traction for chronic low back pain, with or without lower limb symptoms. ^[18] Motorized, intermittent traction, which has been aggressively marketed (eg, VAX-D, DRX9000), likewise did not seem to differ in efficacy from simple intermittent axial traction. Gay et al cautioned against fully extrapolating the results of the available randomized, controlled trials to the distraction-manipulation therapies at present, until further research can be completed that specifically assesses their effects. Research on this approach is ongoing.

Contraindications

No scientific reports clearly delineate contraindications for traction. The practitioner must rely on empiric information and expert consensus. Old age has been cited as a relative contraindication. Most practitioners agree that contraindications for cervical or lumbar traction include, but may not be limited to, the following:

• Ligamentous instability
• Osteomyelitis
• Diskitis
• Primary or metastatic tumor
• Spinal cord tumor
• Severe osteoporosis
• Clinical signs of myelopathy
• Severe anxiety
• Untreated hypertension

In the cervical spine, the practitioner also must take into account the fact that patients with vertebral basilar artery insufficiency may be more susceptible to cerebrovascular complications. Furthermore, patients with advanced rheumatoid arthritis or connective tissue disorders may be at risk for atlantoaxial instability or other complications.

Other, relative contraindications for traction in the cervical or lumbar spine include the following:

• Midline herniated nucleus pulposus
• Acute torticollis
• Restrictive lung disease
• Active peptic ulcer
• Hernia
• Aortic aneurysm
• Pregnancy

Akinbo et al monitored systolic and diastolic blood pressure, heart rate, rate pressure product, and electrocardiography (ECG) at 5-, 10-, and 15-minute intervals during administration of cervical traction at 7.5%, 10%, or 15% of the patient’s total body weight (TBW). ^[19] In comparison with premeasured baseline values, decreases were noted in systolic and diastolic blood pressures and rate pressure product for all subjects in all three groups. Although the change was not statistically significant for the 7.5% group, it was for the 10% and 15% groups. There was no significant difference in heart rate or ECG variables in any group.

The authors of this study recommended monitoring these values before and immediately following application of cervical traction, especially in at-risk patients or those with known blood pressure or cardiac problems. ^[19]

Referral considerations

The physiatrist who refers patients for traction must write a detailed and specific prescription that includes at least the following patient information:

• Age
• Sex
• Diagnosis
• Underlying medical conditions
• Precautions needed
• Recommended follow-up

Traction should not be the sole treatment approach; rather, it should be one part of a comprehensive rehabilitation treatment program. The most effective use of traction is likely to improve the patient's activity level, mobility, and overall function.

Specific items to outline in traction referrals also should include the following information:

• Position (of the body, neck, or hip and knee)
• Mode of application (continuous or intermittent)
• Weight to be applied
• Concurrent modalities (eg, heat)
• Frequency and duration of treatment
• Reevaluation guidelines and time frames
• Guidelines for discontinuance
• Therapeutic goals

Cervical and lumbar traction

Cervical traction generally is accomplished with a free weight–and–pulley system or an electrical, motorized device. Adequate pull is achieved by using a head or chin sling attached to a system that can provide pull in a cephalad direction. Motorized devices are easily applied but require the patient to be attended by an appropriately trained and credentialed clinical professional.

Free weight–and–pulley systems often are used in the home with at least 20 lb of water or sand and a pulley system attached to a door. If a minimum tractive force of 20 lb is not achieved, the system is likely to fail to reach therapeutic results. Patients should be advised not to attempt cervical traction at home alone, because they may find themselves in uncomfortable positions and may need assistance with removing the traction device(s).

Most home traction systems are difficult for patients to set up without assistance. Home cervical traction may cause increases in pain or may fail to produce significant pain relief unless professionally monitored on a periodic basis. At the initiation of home traction, the patient should be required to demonstrate proper use of equipment to the satisfaction of the prescribing physician or licensed treating clinician.

In the lumbar spine, adequate pull with weights and pulleys or motorized devices to achieve vertebral distraction usually can be obtained with the proper apparatus. Generally, a harness is attached around the pelvis (to deliver a caudal pull), and the upper body is stabilized by a chest harness or voluntary arm force (for the cephalad pull).

If the goal of tractive force is to distract lumbar vertebrae, 70-150 lb of pull usually is needed. Friction between the treatment table and patient's body usually requires tractive force of 26% of the total body weight (TBW) before effective traction to the lumbar spine is possible. Many traction devices use a split table that eliminates the lower body segment friction.

Body weight theoretically should provide enough pull to distract lumbar vertebrae and eliminate mechanical devices. Gravity traction is applied almost exclusively in the lumbar region. After 10 minutes of inversion traction, documented increases in intervertebral separation are noted; however, side effects also are frequently reported, including increased blood pressure, periorbital petechiae, headaches, blurred vision, and contact lens discomfort.

A study from Hungary reanalyzed an old method of applying traction in the treatment of patients with lumbar or cervical diskopathy. ^[20] Patients were vertically suspended by a special harness in a warm-water bath, with a specified amount of weight applied to the lower limbs. One harness allowed for traction on the lumbar spine, while the other focused on the cervical region. The study participants had land-based physical therapy exercises and the weight-bath therapy, while a control group only had the exercises.

In this study, therapeutic benefit was perceived to be greater by patients treated with a combination of the weight-bath and exercise than by patients in the control group following treatment and at 3-month follow-up. ^[20] The treatments were well tolerated, and no adverse effects were reported. Although the study concluded that this form of traction treatment "is a relatively straightforward, non-invasive, and low-cost intervention that can be implemented anywhere," further research may be needed to corroborate the findings of this pilot study. Such investigation may need to be supplemented with cost and feasibility data before widespread implementation is initiated.

Additional considerations

In cervical traction, determining sitting versus supine position is based upon the patient's comfort and ability to relax. Maximal distraction generally occurs between 20º and 30° of flexion without rotation or side bending.

Studies have shown that in the cervical spine, larger improvement in range of motion (ROM) with less accompanying pain was noted in patients subjected to intermittent traction of a 20-lb peak (10 seconds on, 10 seconds off, for a total of 15 minutes of treatment time) than in patients subjected to 15 minutes of manual or static traction of 25 lb. Constant cervical distraction forces of 30 lb generate maximum vertebral separation in 7 seconds or less, and no further separation was gained by applications of up to 60 seconds.

Supine position is chosen most commonly for lumbar traction because the sitting position may result in outcome-limiting discomfort from the harness. Hip flexion of 15-70° routinely is incorporated to cause relative lumbar spine flexion; this may facilitate optimal vertebral separation.

Studies, in addition to patient preference, suggest that some relative advantage exists to an intermittent versus continuous protocol of cervical traction. Some studies report that continuous traction is necessary in the lumbar spine to fatigue muscles and allow strain to fall on joints; however, no statistical difference has been observed with either continuous traction of 100 lb for 5 minutes or intermittent traction of 100 lb, peaking for 15 minutes. As in traction on the cervical spine, improved patient tolerance favors an intermittent protocol.

In the sitting position, application of approximately 10 lb is required to counterbalance the patient's head in cervical traction. Traction of 30 lb applied to a neck flexed up to 24° can cause vertebral separation, but an increase of force to 50 lb has been found to produce no clear-cut additional separation. In the lumbar spine, a pull, which equals approximately 50% of the weight of the body part, is needed to overcome friction. As noted for the lower body, this amounts to approximately 26% of total body weight.

In 2006, Akinbo et al published a study examining what the most beneficial amount of TBW would be for cervical traction. ^[19] Trials were done with patients randomly assigned to one of three groups, with each group receiving traction of 7.5%, 10%, or 15% of the patient’s TBW. The patients in the treatment group using 10% of their TBW demonstrated the highest therapeutic efficacy with the fewest side effects, compared with the 7.5% and 15% TBW groups.

Duration of therapy

An optimal duration of traction has not been clearly defined. Recommendations have ranged from 2 minutes to 24 hours in the cervical spine. A duration of approximately 15-25 minutes is commonly prescribed. Cervical traction generally is prescribed at a frequency of daily for the first week and then every other day (ie, three times per week) for a total treatment duration of approximately 3-4 weeks. In the lumbar spine, treatment generally is recommended in the 8- to 40-minute range per session, daily for the first week and then every other day (ie, three times per week) for a total of 3-4 weeks.

In cervical and lumbar traction, goals of treatment determine the time course, as well as the end point of treatment. Possible treatment end points may include pain relief, achievement of normal ROM, return to work or other desired functional activity, lack of improvement in symptoms, or inability of the patient to cooperate with treatment.

Very few scientifically rigorous studies exist that allow the effect of traction to be distinguished from the natural history of pathology (eg, radiculopathy). Criteria have been suggested that would allow the true effects of traction to be delineated. These criteria include the following:

• Randomized controlled trials
• Blind outcome assessments
• Equivalent cointerventions
• Monitored compliance
• Minimal contamination and attrition
• Adequate statistical power and description of study design and interventions
• Relevant, functionally oriented outcomes

To date, no traction outcome study has been published that fully incorporates these criteria.

Despite inadequacies in the literature, randomized, controlled trials that meet some of these criteria do provide some insight into the efficacy of traction as a treatment modality. A review of randomized, controlled trials of traction analyzed English-language studies conducted between 1966 and 2001; the only conclusion that could be drawn, based on that review, was that there is poor evidence to support the effectiveness of traction for back pain relief. ^[21]

A subsequent review by Graham et al arrived at two clinical conclusions. One conclusion favored the use of intermittent traction over a continuous protocol, and the other did not support the use of continuous traction. ^[22] On the basis of the methodologic quality of the numerous studies reviewed, the reviewers felt that there was inconclusive evidence overall for either form of traction.

A systematic literature review by Clarke et al further supported the aforementioned conclusions regarding traction for low back pain. ^[17] Through an examination of randomized clinical trials, the authors determined that the evidence did not support the intermittent or continuous use of traction alone to treat low back pain in mixed groups of patients with this condition, whether or not sciatica was present. Owing to inconsistent results and methodologic problems in most of the studies involved, the authors also did not recommend traction for patients with sciatica and stated that because the available research was insufficient, they were unable to comment on the use of traction in combination with other therapies.

A 2013 Cochrane review of 32 randomized, controlled trials involving 2762 participants who had low back pain with or without sciatica concluded that traction, whether used by itself or in conjunction with other therapies, had little or no effect on pain intensity, functional status, global improvement, or return to work in these patients. ^[15] The authors noted that the quality of the evidence was limited and stated that the use of traction to treat nonspecific low back pain could not be determined by the best available evidence.

What can be reasonably derived from these studies is that more work must be done before evidence-based recommendations can be formulated for the application of traction to back pain. ^[23] Additional evidence is also needed to evaluate the optimal type and position of the tractive forces for various clinical conditions, as well as to assess the use of traction as one component of a patient’s overall treatment rather than as an isolated modality.

Lumbar traction

The Agency for Health Care Policy and Research (AHCPR) review of the literature on traction resulted in the conclusion that "spinal traction is not recommended in the treatment of acute low back problems." In addition, the 1996 and 1999 guidelines published by the UK Royal College of General Practitioners (RCGP) stated that "there is little evidence to support the continued use of traction in the management of acute low back pain (LBP)."

Despite these recommendations, the widespread use of lumbar traction remains relatively high in the United States and beyond, with as many as 20% of US patients and 30% of those with low back pain and sciatica receiving traction as a complete or partial treatment approach.

Studies that claim improvement after traction typically report modest and very short-term improvements, with limited or no improvement in overall function. Additionally, these studies have significant design flaws. Although a particular group of patients may benefit from a specific type of traction for either short- or long-term improvement in functional outcome, the literature currently does not identify this patient population. In addition, it is important to note that whereas high-quality evidence supporting the use of traction for the treatment of low back pain is currently scarce, the available data in the literature are also insufficient to show that traction is ineffective for this problem. ^{[17, 24, 25]}

Cervical traction

Few randomized, controlled trials address patient outcomes after cervical traction. Although many studies have produced statistically significant findings, the actual clinical significance of those findings is not clear. Some studies have been published on new protocols for cervical traction, as well as on new devices for traction application. Additional evidence for the efficacy of these devices and methods appears to be needed before widespread application can be made or recommended. ^{[26, 27]}

Therapeutic manipulation has been practiced in almost all countries of the world since at least the time of Hippocrates; early references have also been found in Egyptian hieroglyphics.

The past few decades have seen a rapid growth in manipulation and manual therapy and an increase in public demand for its use. Some healthcare professionals' opposition to the use of manipulation is explained by the fact that manipulation requires skills significantly different than those acquired in allopathic medical schools. This difference separates practitioners who possess manipulation skills from those who do not. The techniques used in manipulation also fall outside the traditional mainstream of allopathic medicine.

Manipulation procedures are used in many ways by a variety of practitioners. The most common goal of a manipulative treatment is to increase the mobility of a particular area or region of the musculoskeletal system where restrictions are encountered. Some practitioners focus on pain relief as a main outcome measure; others seek enhanced mobility or reduction in restriction of vascular or lymphatic congestion as it relates to the rest of the body.

Most of the 90 million annual manipulations performed in the United States by physicians and other practitioners are for complaints of musculoskeletal back and neck pain. ^[28] Manipulation generally is directed at restoration of normal motion and elimination of pain secondary to disturbed biomechanics.

The majority of the research on the use of manipulation focuses on its application to the cervical and lumbar spine, as well as on treating painful conditions in these areas with either mobilization or thrust-type maneuvers. It is important to realize that there are many other types of manipulative techniques, and which one is chosen should be based on a thorough history and physical examination of the patient and on the particular musculoskeletal issue to be treated.

Definition

A consensus definition of manipulation is "the use of the hands applied to the patient incorporating the use of instructions and maneuvers to achieve maximal painless movement and posture of the musculoskeletal system." Most common types of manipulation involve passive mechanical forces applied to specific vertebral segments, regions, or other joint segments of the musculoskeletal system, with a primary goal of restoration of diminished ROM.

Availability of manipulation care

The availability of manipulation care varies significantly, depending on geographic location and regional practice patterns. Physiatrists who wish to use manipulation but who do not wish to provide it themselves generally refer patients either to another physician with appropriate training and expertise or to a licensed nonphysician practitioner who has completed appropriate training and possesses adequate manipulative skills.

Referral to another physician practitioner often works well, but potential problems exist, especially regarding patient referral. This issue may be addressed through a specific referral that states the exact nature and scope of the evaluation and treatment requested, that encourages discussion with the referring physician, and that makes clear the intention of the physiatrist to resume the remainder of the patient's care. If the referral is to a licensed nonphysician practitioner, the physiatrist should first diagnose the appropriate problem and write a specific prescription for desired clinically appropriate manipulation.

Manipulative care can be provided as part of a comprehensive treatment program; however, the physiatrist should write a detailed prescription for the specific area to be treated and identify the diminished motion to be restored and other treatment objectives, as well as the frequency and length of treatment and precautions, if applicable. This enables the physiatrist to monitor patient progress objectively and determine the end point for and benefit of manipulative treatment.

The three main obstacles for the physiatrist interested in performing manipulation are as follows:

• Acquisition of skills
• Maintenance of skills
• Economic considerations

Initially, manipulative techniques are best learned on colleagues and fellow learners under close supervision. Studies suggest that the minimum learning time required might range from 3 to 12 months, depending upon the modality being learned. This extended period of time has significant ramifications for the practitioner.

Because of enhanced safety and the small potential for harm, sufficient skill can be acquired by most practitioners in 1-2 weeks of formal training for each of the types of manipulation, including isometric/muscle energy, counterstrain, myofascial release, and articulatory techniques. Training time for these approaches is shorter, because inappropriate or incorrect indirect techniques, unless repeated frequently or over a prolonged period of time, rarely cause detrimental effects.

Postdoctoral training programs, such as those approved or offered by the American Academy of Physical Medicine and Rehabilitation, the American Association of Colleges of Osteopathic Medicine, and other organizations, may provide a means by which the physiatrist can become acquainted with the skills necessary to begin manipulative care. Interest among physiatric residents in acquiring manipulative skills is high, and this fact has expanded training opportunities for physicians. Many residency programs now include required and/or optional training in manipulative skills.

Maintenance of manipulative skills is fairly easy for a full-time practitioner; however, it may be more difficult for the physiatrist whose practice does not feature a high volume of manipulative care. Infrequent use of manipulative skills results in decreased competence, but the actual minimum frequency of use needed to maintain competence or excellence varies considerably among practitioners. Manipulation, if performed and documented appropriately, can be very time-efficient and financially viable.

Indications

Manipulation is appropriate for a variety of musculoskeletal problems, especially those of the thorax, rib cage, upper and lower extremities, back, pelvis, and neck. It is also useful when loss of motion or function is encountered or when localized tenderness or pain is noted on induced motion.

Some clinical situations (eg, acute fractures, disk herniations with neurologic signs, tumors, acute inflammation, joint disease) may not respond to manipulative care because of local conditions that may constitute hypermobility or other contraindications. It is important to remember also to exclude systemic or visceral pathologic conditions, or at least place them under concurrent care of the practitioner.

Some physicians use manipulation for treatment, whereas others provide it in a more prophylactic manner.

Contraindications

Different manipulative approaches vary with regard to their degree of invasiveness. Because of the higher forces involved, direct techniques are the most invasive and therefore are more likely to be contraindicated.

Absolute contraindications for manipulative care, especially indirect techniques, are very rare. Few relative contraindications exist. Manipulative care should be performed only for hypomobile vertebral segments or other structural dysfunctions deemed amenable to manipulation. Accurate structural diagnosis is critical. Inadequate practitioner skill is a major contraindication for all types of manipulative care.

Articulatory techniques are contraindicated for patients with the following:

• Vertebral malignancy
• Infection or inflammation
• Myelopathy
• Multiple adjacent radiculopathies
• Cauda equina syndrome
• Vertebral bone disease
• Bony joint instability
• Cervical rheumatoid disease

Direct-technique manipulation (eg, high velocity/low amplitude) is contraindicated in the cases above and, additionally, in the presence of the following:

• Spinal deformity
• Systemic anticoagulation treatment
• Severe diabetes or atherosclerotic disease
• Degenerative joint disease
• Vertebral basilar disease or insufficiency
• Spondyloarthropathies
• Ligamentous joint instability or congenital joint laxity
• Aseptic necrosis
• Local aneurysm
• Osteoporosis
• Acute disk herniation
• Osteomalacia

Haldeman et al performed a retrospective review of patients in whom the occurrence of stroke was temporally associated with cervical spine manipulation. ^[29] They concluded that no known mechanism exists to predict who is at risk for such an event and that stroke is an inherent and idiosyncratic risk associated with this type of treatment, as well as an exceedingly rare complication.

Patients with a tendency toward somatoform fixation in painful anatomic areas, as well as those with obsessional neurosis, are poor candidates for direct manipulative techniques. Pregnancy and known threat of miscarriage are absolute contraindications only for direct manipulative techniques. Conservative indirect techniques are considered safe (as long as they are performed by a competent practitioner) well into the latter stages of pregnancy.

Objective radicular signs are a contraindication for direct-thrust techniques of all kinds. Active myositis or infection may constitute a contraindication for isometric care because of the need to provide active muscular contractions. Functional techniques, counterstrain, or other indirect approaches may be applied safely in these conditions. No contraindications have been documented for functional or counterstrain techniques.

Patient selection

The physiatrist usually can identify, through a focused musculoskeletal history and physical examination, patients who are most likely to benefit from manipulative care. Although some manipulation techniques have applicability to hospitalized patients, most patients for whom manipulation is considered appropriate are encountered in the outpatient setting. This constituency includes patients with structural problems (eg, vertebral rotations, pelvic asymmetries, sacral torsions, other entities in which diagnosis relies on palpatory skill).

A general examination should be performed on each patient, which should include assessment for underlying pathology such as fractures, herniated disks, strains, hematomas, joint injuries, and peripheral and central neurologic injuries. The use of additional diagnostic studies may be considered as needed.

The physiatrist contemplating manipulative intervention performs a focused, appropriately detailed neuromusculoskeletal history and structural examination in areas suggested by the history, symptoms, or the general examination. This involves observation, active gross- and fine-motion assessment, and general palpatory/motion examination. Success of manipulative treatment often depends upon accurate palpatory diagnosis. Palpatory and segmental autonomic changes may be significant components of the structural diagnosis.

Generally included in the evaluation of vertebral or segmental levels are the following:

• Bony structure asymmetry
• Restricted vertebral motion relative to adjacent vertebrae in flexion, extension, side-bending, and rotation
• Tissue-texture changes
• Local tolerance to palpation or induced motion
• Tenderness elicited over vertebral processes or by induced motion

As part of the musculoskeletal examination, the passive ROM, symmetry, and amount of force needed to achieve full or maximal safe range must be evaluated. These are assessed in terms of quality or end-feel of motion. Combinations of vertebral motion will also be evaluated (flexion, rotation, etc).

Springing of the vertebrae and examination of tenderness or local pressure on interspinous ligaments often are useful techniques for determining musculoskeletal function and loss of joint mobility. Subcutaneous tissue-texture changes, such as edema or fibrosis, may be noted by palpation and may indicate musculoskeletal pathology with associated segmental autonomic changes.

The physiatrist should include an examination of the ribs, occiput, and pelvis in the structural examination. Hypermobile musculoskeletal segments may not be amenable to manipulative intervention but may indicate the presence of hypomobile segments in other locations and, if nontender, may be amenable to successful manipulation to resolve distant hypermobility.

Thorough structural examinations, as described, may add 5-10 minutes to an initial visit and less than 5 minutes to a follow-up patient examination. A thorough structural examination will usually allow the physician to most appropriately focus treatment on the area of greatest need. By localizing the main area of restriction, the treating physician often can minimize the dose and frequency of the manipulative intervention. ^[30]

The physiatrist choosing manipulation should possess a relatively high degree of basic palpatory skills so that referral to another physician or manipulative practitioner includes specific identification of structural dysfunction. Additionally, palpatory examination allows the physiatrist to determine which areas need manipulative treatment and to establish a potential end point of manual care.

Key lesion

According to the American Association of Colleges of Osteopathic Medicine (2017), a key lesion is defined as “the somatic dysfunction that maintains a total dysfunctional pattern including other secondary dysfunctions.” ^[31]  For example, a manipulative practitioner who encounters a persistent problem even though noticeable dysfunctions have been treated may determine that there is an untreated key (or causative) lesion. ^[32] “The term ‘key lesion’ is used because, when it is corrected, it is like using a key to unlock the remaining somatic dysfunctions." ^[33]

The Glossary of Osteopathic Terminology recognizes the key lesion as synonymous with primary somatic dysfunction. ^[31] Structural examinations search for somatic dysfunctions that may be responsible for a “patient’s symptomatology or dysfunctional physiology.” ^[34] Finding and recognizing the “larger deformities that give rise to the secondary somatic dysfunction” is the focus for the practitioner. 

During examination, the practitioner performs an initial screening exam on all regions of the body, followed by a scanning evaluation of those areas recognized as having abnormalities. The key lesion is most likely located in the region of the greatest restriction and therefore is the region evaluated first. Osteopathic medical education emphasizes instruction in and clinical use of manipulative screening methods for evaluating patients with the aim of efficiently and accurately locating the most restricted pertinent structure in the patient's body.

In theory, when a practitioner treats the key lesion, this “allows for the pattern of dysfunction to unravel.” ^[32]  When a patient sustains an injury and presents for early treatment, the key lesion will probably be the only dysfunction. If this lesion is not resolved, the patient's body will be much less likely to resolve any further injuries. ^[33]  Once the key lesion is addressed, many of the secondary somatic dysfunctions will be resolved by the body’s own homeostatic mechanisms. Patients who return with the same complaint either are continually reinjuring themselves or have an unresolved key lesion. ^[33]  

Addressing the key lesion is essential for the individual to achieve optimal health. “A great deal of time and effort is often expended searching for the key lesion, as it is this dysfunction that, when corrected, will result in the greatest change for the better in the patient’s overall body physiology.” ^[34]

Patients may present with identical complaints; however, their causative key lesions are likely to differ. Differences in size, musculoskeletal framework, past medical and surgical history, and compensatory mechanisms may result in different key lesions. For example, when a patient presents with a complaint of neck pain, a proper history and physical examination would be warranted to rule out “red flag" pathology before determining that somatic dysfunction is the contributing factor. Once possible “red flags” are eliminated as possible causes of the presentation, the practitioner can begin screening for the causative somatic dysfunction. 

A common key lesion that presents with neck pain, for example, is a restricted diaphragm, which can be palpated along its anatomic attachments, such as the borders of the twelfth rib and the L1-2 vertebrae. The examiner can also appreciate diaphragmatic restriction visually by asking the patient to inspire deeply and observing the extent to which the abdomen rises with diaphragmatic contraction. Somatic dysfunction of the diaphragm occurs most often as a result of improper breathing technique or in cases of trauma to the rib cage.

Structure and function are interrelated: If structure is impaired, functionality will be as well. ^[35]  If the structure of the diaphragm is impaired, its capacity for appropriate lengthening and shortening the chest cavity will also be impaired. If the primary mechanism for changing the negative pressure within the chest is impaired, secondary mechanisms elevating the rib cage will compensate, resulting in overactivity of accessory muscles such as the sternocleidomastoid, the scalenes, and the serratus anterior, which elevate the sternum and ribs.

Somatic dysfunction is often a representation of the body’s effort to maintain homeostasis—in this case, to maintain adequate negative pressure for lung expansion. If the neck muscles are hypertonic, then it can be expected that the structure of the cervical vertebrae will be altered and that their function will thereby be altered as well. This will ultimately lead to the patient experiencing neck discomfort from inappropriate overuse and hypertonicity of respiratory accessory muscles.

If the practitioner were to treat only the cervical muscles and vertebrae, the patient would experience only temporary pain relief and would most likely have a recurrence of the original complaint. This illustrates the value of first finding and treating the key lesion, the root cause of the somatic dysfunction. Once the diaphragm is adequately treated, the cervical dysfunction will resolve.

To summarize, a holistic screening of the body is necessary for adequate evaluation of the patient; the particular method employed matters less than ensuring that the proper elements are used. Anatomic and physiologic considerations are important in patient evaluation if the practitioner is to fully understand and assess the possible regions that may contribute to the presenting complaint.

A brief discussion of direct versus indirect treatment is germane to the understanding of the rationale for choosing a particular technique. Once an area of restriction, or somatic dysfunction (see Hypothesized Etiology of Somatic Dysfunction below), is palpated, the means of correction must be chosen.

A direct technique engages the motion barrier; this means that the practitioner directs forces into and through the motion barrier. On the other hand, an indirect technique allows the body’s inherent neurologic or intrinsic forces to release the restriction, as the practitioner positions the area to be treated opposite the direction of a restriction.

For example, if pain and reduced motion are elicited by actively rotating a patient’s neck to the patient’s right side, it can be deduced that the patient’s restriction is on the right. Thus, if the treatment selected takes the patient’s neck further to the right (ie, into the restriction or barrier), this is a direct treatment. Conversely, if the patient’s neck is rotated to the left (ie, away from the restriction or barrier), it is considered an indirect treatment.

Direct-thrust techniques

Direct-thrust (eg, high velocity/low amplitude) techniques, including European mobilization with impulse, involve diagnosis of dysfunction of a vertebral segment by identifying position or motion abnormalities or related tissue-texture changes, including tenderness to (1) palpation or (2) induced motion.

The practitioner rotates, side/lateral-bends, and either flexes or extends the adjacent vertebral segments, locking the facet so that further motion is limited to the segment in question. The vertebral segment is then moved passively to its limit of motion (or barrier) in order to remove "unneeded" or slack motion, and a small force, localized to the specifically identified joint, is applied to hold that position. Brief, controlled thrust is applied in the direction perceived as limited, and a small motion in the desired direction then occurs as the vertebra crosses its barrier.

Forces, duration of actions, acceleration, and displacement values for direct-thrust techniques have been measured. These forces peak in the range of 100-400 N over a period of approximately 150 ms. Direct manipulative technique forces applied over transverse or spinous processes are short-lever techniques. If force is applied distant to the vertebrae through the locked column, the procedure is considered a long-lever direct technique. All direct-thrust techniques must have forces well localized and specifically placed, and structural diagnosis must be adequate before their safe application.

Articulatory technique

Articulatory technique (low velocity/high amplitude) involves passive movement of a vertebral joint within reduced ROM, defined by its resting position and the dysfunctional limitation of motion. Extent of motion at its end point may vary, but the end point and the dysfunctional barrier become the same, with the barrier becoming attenuated with repeated motion. The quality or feel of induced motion, in addition to the quantity of force and excursion, are normalized by this procedure. A small amount of additional force occasionally may take the vertebra through its barrier or restriction.

Indirect positional techniques

Indirect positional techniques (eg, counterstrain and functional techniques) are based on the underlying principle that somatic dysfunction or hypomobility is caused by an inappropriately firing muscle group rather than by shortened, passive tissue (eg, joint capsule, ligament, or fascia). Thrust, articulation, and muscle energy techniques employ forces that could be expected to lengthen shortened, passive tissues, whereas these positional techniques change an inappropriate engram of muscle behavior.

Counterstrain

Developed by Jones, counterstrain is an indirect myofascial technique that shares with functional technique an emphasis on relative positioning of a joint or body part as an essential component of treatment. ^{[36, 37]}

Counterstrain treatment involves placing a joint or body part into position of maximal ease or comfort, thereby relaxing ligamentous and myofascial soft tissue. This relaxation allows inappropriately shortened muscles to reset their spindles, which then normalizes proprioceptive input into the spinal cord. The restricting muscle generally is shortened excessively by this positioning (eg, counterstrained), and its antagonist muscle is overstretched (eg, strained) gently in the process.

The optimal treatment position is found by minimizing pain associated with palpatory pressure over a tender point, and once this position of maximum ease is found, it is held for at least 90 seconds, with concurrent tender-point monitoring. During this time, tenderness should fade to no more than 30% of its initial value.

Occasional small, fine-tuning, passive positioning movements with verbal feedback from the patient may be needed. Tenderness is part of this feedback system; therefore, the patient must respond to the practitioner's questions. The patient is slowly returned to a neutral position in one plane of motion at a time to prevent recurrence of inappropriate muscle firing.

Counterstrain is considered an indirect technique because positioning is always in a direction away from the restricted motion. If multiple tender points are encountered, they are treated in order of decreasing tenderness. The areas of the highest accumulation of tender points (first proximally and then distally) are then addressed.

Tender points are found beneath the skin through palpatory examination over shortened and restricted muscles or over related anatomic structures (eg, tendons, muscles, and ligaments). They generally do not coincide with trigger points or points associated with fibromyalgia.

Counterstrain tender points typically are small, fibrotic, discrete areas thought to be manifestations of distal somatic dysfunction and are not associated with other signs of fibromyalgia, nor are they paired. They are distributed widely in generally reproducible locations, depending on the nature and location of associated somatic dysfunctions. Those associations are not based on known neurophysiologic or neuroanatomic referral patterns.

Counterstrain is considered safe, effective, gentle, and atraumatic; consequently, it is a very useful technique for the older, hospitalized, or immune-compromised patient, as well as for apprehensive patients and children. Counterstrain techniques are easy to perform, forgiving for the novice learner, and easily incorporated by the patient into a prescribed home exercise program.

Functional techniques

Functional techniques, like counterstrain, have a methodologic approach oriented to resetting inappropriate afferent impulses from nociceptors and mechanoreceptors, resulting in efferent alpha motor activity to the skeletal muscle, by placing the joint or body part into a position of maximum ease. In contrast to counterstrain, however, the position is found and monitored by the practitioner, who senses either increased resistance to trials of small, induced motions or increased tissue tension of the nearby tissue when motion is induced. The most relaxed position is held in this balanced state.

Functional technique practitioners feel that inherent body motions (eg, respiration) allow the firing pattern of the afferent muscles to reset so that they are normalized in a neutral position. This approach is also unlike counterstrain in that it does not make use of tender points and may be somewhat more objective (because the practitioner's palpatory findings determine positions of balance).

The practitioner puts the patient through a sequence of positions, with the goal of progressing toward anatomic neutral as the position of maximum ease or balance. Functional techniques are useful in acute and chronic conditions because they focus on the quality, rather than the quantity, of motion, with restoration of normal function implying normal quality and ROM. Functional techniques require significant experience on the part of the practitioner.

Muscle energy

Muscle energy is a direct nonthrust technique (also known in the United States as isometrics and in Europe as mobilization) and has a strong relation to proprioceptive neuromuscular facilitation.

The physician positions the patient and removes slack as in direct thrust procedures and subsequently prevents active motion of the affected vertebral segment away from its barrier. The patient then exerts minimal to moderate isometric force against resistance offered by the physician for approximately 5-10 seconds and subsequently relaxes. The physician then finds that the barrier has been displaced and that the affected segment moves beyond its original barrier. This procedure is repeated two or three times, with diminishing gains and increased ROM.

Soft-tissue techniques

Soft-tissue techniques use mechanical stretch of skin, muscle, and fascia to increase motion. Lateral and linear stretch and deep inhibitory pressure are the procedures most commonly used. These procedures are useful in virtually all patients and may function as the first step in manipulative treatment involving multiple techniques or may be used as a single method to address a specific treatment goal. In particular, they are very valuable in optimizing fluid circulation in and adjacent to soft tissues, enhancing venous and lymphatic flow, and acting as a mechanism for decongestion of body regions impacted by trauma or disease.

Soft-tissue techniques may also help decrease muscle and other tissue hypertonicity and spasm, in addition to serving as a mechanism to relieve pain. Proposed analgesic mechanisms include facilitating release of endogenous opioids; modulation of spinal reflex pathways via stimulation of mechanoreceptors, proprioceptors, and nociceptors; and enhancement of general physical tone.

There are many types of soft-tissue techniques. Some involve application of forces at right angles to the long axis of muscles and soft tissues (lateral stretch), along the long axis of such tissues (longitudinal stretch), in both directions at the same time, or via steady superficial or deep pressure.

A highly specialized soft-tissue technique is fascial distortion, which occurs in the following six main types:

• Trigger bands (where wrinkles or minor tears occur in fascial tissue)
• Herniated trigger points (where fascia tissues from one compartment partially shift into an adjoining one)
• Fascial continuum distortion (where fascial tissue connections are disrupted)
• Folding distortion (where fascia excessively unfolds or is compressed with a twisting force)
• Cylinder distortion (where interwoven dense fascia fibers become entangled or caught in a cylindrical fashion)
• Tectonic fixation (where there is a loss of circulating lubricant fluid between fascial tissue surfaces, resulting in decreased mobility and joint stiffness)

Each of these fascial distortions is addressed with a specialized soft-tissue manipulative approach.

The overall purpose of soft-tissue techniques is to relieve fascial and superficial muscle tension. These techniques are easily learned and can be incorporated into clinical practice with virtually no difficulty.

Myofascial release

Myofascial release techniques are directed at vertebral, segmental, or generalized hypomobility. Myofascial release can be indirect (ie, when a restricted area is placed into a position of little resistance until subsequent relaxation occurs) or direct (ie, when the affected area is placed against a restrictive barrier with constant force until fascial release occurs). All the myofascia of the body are interconnected, and when one area is tight or restricted, diminished movement occurs not only locally but (potentially) in distant, related areas.

Myofascial release practitioners palpate to assess tissue response and adjust applied forces of stretch, pressure, twist, or traction until affected tissues change toward normal. This progression may occur over a short time and is referred to as release. The mechanism of release may be biomechanical or neuroreflexive; however, fascial resistance to forces applied should be symmetric, and the tissue should be relatively mobile and responsive to force being applied.

In myofascial release, the mechanical approaches of direct thrust, articulatory technique, and muscle energy are combined with the neuroreflexive approaches of counterstrain, functional technique, and soft-tissue technique. Effective use of myofascial release requires considerable palpatory skill and experience, and training time is relatively long compared with that for other manipulative approaches.

Craniosacral manipulation

Craniosacral manipulation is based on the concept of a primary respiratory mechanism (ie, a cyclic, palpable, rhythmic wave of inherent motion appreciated most easily in the cranial and sacral areas). This wave may represent a continuous state of flux in the cerebrospinal fluid (CSF). This primary mechanism may entail inherent mobility of the central nervous system (CNS), CSF fluctuation, cranial bone articular mobility, involuntary motion between the sacrum and ilia, and mobility of interspinal and intercranial membranes.

The craniosacral practitioner palpates the head and/or sacrum to feel pulsations of the wave motion, occurring in the range of 8-12 pulses/min, as well as to evaluate symmetry, regularity, frequency, and amplitude of the wave. When abnormalities are found, general pressure is applied to the skull and sacral areas to restore the wave to normal symmetry, rhythm, and amplitude.

This technique is considered somewhat controversial among nonpractitioners; its largest subset of potential patients may be infants with failure to thrive, birth defects, or head injuries, as well as adults with neurologic or CNS pathology. The growth in popularity of this manipulative approach requires physicians to have at least passing familiarity with it. Proficiency with craniosacral manipulation requires considerable training and experience.

Duration of therapy

Direct techniques (eg, high-velocity/low-amplitude thrust) usually have immediate effect, and improvement is seen within 1 week. Indirect techniques may take longer for the effect to be seen. Caution must be used to avoid unnecessary continuation of treatment when pain relief does not correlate with biomechanical improvement. If the patient's condition does not improve objectively within 2-4 weeks, reevaluation of the structural diagnosis, manipulative approach, or other therapeutic plan is indicated. Determine the duration of each course of therapy on a case-by-case basis.

The most commonly reported side effect of manipulation is a transient increase in discomfort lasting approximately 6-72 hours. Minor, temporary autonomic effects (eg, early or increased menses, increased perspiration, vasomotor changes) have been reported.

Evidence for the benefits of manipulation is mounting. Proponents report excellent results in treating acute, as well as chronic, musculoskeletal problems. Empirically, these outcomes are comparable to those achieved with more conventional treatments, many of which carry no proof of efficacy.

Manipulative care has been shown to decrease use of medication and physical therapy, to be superior to conventional treatment and placebo manual care, and to be most efficacious in persons with noncomplicated acute low back pain. ^[6] It results in less disability and faster recovery, as well as in greater improvement in pain and activity tolerance, and is a valuable adjunct to an ongoing exercise program. It has been shown to be useful in the treatment of upper, middle, and perirespiratory infections, as well as advanced cardiopulmonary disease, headache, and neck pain.

Few risks are involved in manipulative care. Complications from isometric or articulatory treatments have not been reported. The number of reports of complications from direct-thrust manipulation actually is quite small in comparison with the number of manipulations performed annually. Most potential complications of manipulative care are avoidable. ^{[38, 39, 40]}

Complications of manipulation generally arise because of poorly skilled/trained practitioners or result from the performance of contraindicated procedures. Most reported complications involve direct-thrust (high velocity/low amplitude) techniques that generally have been done in the cervical region, and in almost all cases, the neck was extended inappropriately during the procedure. No documented or anecdotal reports of complications resulting from articular, isometric, counterstrain, functional, soft-tissue, or myofascial release techniques exist.

Extremely serious consequences may occur with very low frequency (estimated to be ~1 case in 1-1.5 million manipulations). In 1995, Wiesel remarked in The Back Letter, "As to whether or not healthy patients should be concerned with the risk of cervical manipulation, the risk appears to be quite small." ^[41]

Risk to the patient is minimized by proper positioning of the individual, with avoidance of extreme positions of flexion, extension, side-bending, and rotation. Careful evaluation and treatment of patients with known or suspected osteoporosis or spinal disease also is important.

Manipulation, specifically its application to the cervical spine, has been mentioned in the lay press. Associations have been made between cervical high-velocity thrust techniques and vertebrobasilar artery strokes and strokelike symptoms. Given the number of such manipulative treatments performed in the United States and Canada alone on an annual basis (estimated conservatively in the tens of millions) and the number of reported cases of such events per year (estimated to be in the single digits), cervical spinal manipulation is a relatively safe procedure.

Nevertheless, a thorough physical examination, including a neurologic examination and an assessment of the patient’s comorbid conditions and risk factors, must be conducted before such manipulation is performed. If a thrusting technique is chosen, the force used should be the minimum necessary to achieve the correction and should be localized as precisely as possible to the restricted segment. Extremes of motion in any direction, but especially cervical extension, should be avoided because these end ranges are the ones most often associated with poor treatment outcomes.

A study by Cassidy et al that specifically investigated the possible link between the risk of vertebrobasilar artery stroke and chiropractic manipulation did not rule out a potential connection between these "rare events" and cervical manipulation. ^[42]  The results, according to the report, "suggest that the association between chiropractic care and [vertebrobasilar] stroke found in previous studies is likely explained by presenting symptoms attributable to vertebral artery dissection. It might also be possible that chiropractic manipulation, or even simple range-of-motion examination by any practitioner, could result in a thromboembolic event in a patient with a preexisting vertebral dissection."

It should also be remembered that this reference does not apply to manipulation performed by a fully trained and licensed physician, nor does it apply to any type of manipulation other than high-velocity/low-amplitude thrust in the cervical spine.

A 2015 Cochrane review evaluated 51 trials involving 2920 participants with acute, subacute, or chronic neck pain to assess the effects of manipulation or mobilization alone against those of an inactive control or another active treatment with respect to various outcome measures. ^[43] Manipulation and mobilization yielded similar results for every outcome at immediate, short-term, and intermediate-term follow-up. Multiple cervical manipulation sessions appeared to provide better pain relief and functional improvement than certain medications at follow-up.

Manipulation in pediatric patients

Manipulation may be used to treat infants and children, as well as adults. ^[44] Particular care must be taken in the application of manipulative treatments to children, especially regarding thrust techniques. Some of the serious adverse events in this population that have been documented include death, subarachnoid hemorrhage and tetraplegia.

A systematic review of manipulation-associated adverse events in children, which included information culled from many case reports, found that such events invariably involved children younger than 13 years and typicallym appeared to be associated with diagnoses not commonly addressed by manipulation. ^[45] The authors performed literature searches using multiple electronic databases for articles published from 1900 to 2005. Given the large number of patients treated with spinal manipulation during this time period, they felt it reasonable to conclude that "adverse events resulting from spinal manipulation are either remarkably rare or underreported."

According to the report, a number of risk factors may predispose a child to an adverse event as a result of spinal manipulative procedures, including "immaturity of the spine, rotational manipulation of the cervical spine, and high-velocity thrust techniques." ^[45] Five of the serious adverse-event reports in this study did not specify the type of spinal manipulation used. Two of the four that reported such events specified that the practitioner used "rapid and/or strong rotational maneuvers."

It can be inferred from reviews such as this that rotational manipulation of the cervical spine should be used with extreme caution in the pediatric population and that young patient age may be a relative contraindication for thrusting, especially rotational, maneuvers. Additional attention to accurate diagnosis and a thorough history and physical examination may prevent such catastrophic outcomes in the pediatric population.

Manipulation is a mechanical intervention. Hypotheses that explain somatic dysfunction usually involve position and treatment of vertebral bodies, muscle, fascial segments, or other body parts, as well as soft tissue. Acute pathologies (eg, fractures, ligamentous tears, tumors, avulsions, joint inflammation) are not considered amenable to manipulation as a primary mode of treatment. Some pattern of neuromuscular behavior resulting in early localization of hypomobility may respond to manipulative care.

Pain and edema may cause immobility, leading to contracture or an abnormal neuromuscular pattern. Precipitating pathology of somatic dysfunction may be largely resolved by the time diagnosis is made; however, pain also may arise from dysfunction and, along with impaired mobility, may be related directly to it. Pain and somatic dysfunction can create a self-perpetuating syndrome.

The musculoskeletal manifestation of restricted movement and impaired mobility of a body segment is known as somatic dysfunction. The condition has also been called an osteopathic lesion, a chiropractic subluxation, a joint blockage, and a loss of joint play, among other terms.

Barrier models have been suggested to explain palpable findings. Normal joints possess an active and a larger, passive range of motion (ROM). A barrier or motion restriction produced by abnormal muscle contraction, ligamentous, or capsular shortening forms in one or more directions between the neutral position and normal limits so that patients are not able to achieve normal range. The manipulation practitioner then applies additional force to achieve normal passive ROM.

The facilitated segment model assumes that a vertebral body, chronically malpositioned by contracture, an overly active muscle, or other somatic dysfunction, floods the segmentally related area of the spinal cord with inappropriate, nonfatiguing proprioceptive impulses. These impulses, in turn, spill over and facilitate outgoing motor neurons and autonomics in the same vertebral segment of the spinal cord.

Pathways are then present for interaction between soma and viscera at related segments, and the palpatory diagnosis of visceral disease and the determination of influence on the viscera are possible. This phenomenon allows asymptomatic, abnormal segmental areas to develop symptoms from general illness, distant disease, or emotional stress. Physiatrists familiar with autonomic hyperreflexia and similar phenomena can relate easily to the concepts of somatovisceral reflexes and segmental spillover.

The mechanical model of altered joint play is distinct from the neurophysiologic hypothesis of somatic dysfunction. All normal voluntary joint motion is accompanied by a wiggling motion in a direction perpendicular or, possibly, tangential to the plane of that motion. This joint play exists because joint surfaces are not perfectly congruent.

Loss of joint play because of soft-tissue restriction may inhibit voluntary motion from absence of the involuntary component. Passive intervention is needed to normalize function because lost joint play is in an involuntary direction. Pain arises, therefore, from poor mechanical function.

The concept of "ease and bind," central to functional and other indirect techniques, uses a model of vertebral motion around a symmetry point where motion in any direction encounters equal tissue resistance. In a dysfunctional vertebra or other musculoskeletal tissue, the balance point is not the anatomic neutral, so that movement in one direction of motion is met by more resistance (bind) than another (ease).

The maintenance of asymmetry arises in proprioceptive and gamma motor spindle sensors, and treatment usually involves passive motion to and maintenance of the ease position so that the spindles can reset their output. The strain-counterstrain method suggests that the aberrant activity of the spindles can trigger reflex patterns and tender points, which can be used to monitor the positional resetting of the spindle output. ^[46]

Models of approach to patients for osteopathic manipulation

There are five models by which osteopathic physicians approach patients and address their concerns and which have direct application to the use of manipulation. The models are as follows:

• Biomechanical
• Respiratory-circulatory
• Neurologic
• Metabolic-energy
• Behavioral

These models provide a versatile pathway by which physiatrists or other manipulative practitioners may use palpatory diagnosis and apply manipulation as a part of optimal treatment.

Biomechanical model

A patient with a purely structural impediment is usually evaluated via the biomechanical model. For example, a patient with an inversion ankle sprain may have subsequent issues with ligamentous laxity, as well as fibular head and gait mechanics; if the injury does not heal properly, a long-term compensatory mechanism may develop virtually anywhere in the related musculoskeletal system. Appropriate manipulation of the ankle and fibula could result in improved mobility and stability of the ankle and fibular head, and related manual treatment may improve vascular circulation, lymphatic drainage, and neurologic reflexes.

Respiratory-circulatory model

Patients with chronic obstructive pulmonary disease (COPD) are good candidates for manipulative care via the respiratory-circulatory model by reason of the structural and functional limitations imposed by the disease and its progression. Manipulation would likely be indicated in COPD patients to facilitate pulmonary and cardiovascular function, as well as lymphatic drainage; manipulation, in this case, to the diaphragm and rib cage can improve chest-wall mobility and thoracic duct drainage, and manipulation of facilitated segments of the cervical and thoracic vertebrae can help normalize autonomic activity by reducing sympathetic and improving vagal tone.

Neurologic model

Manipulation using the neurologic model, considering autonomic function, could prove helpful, for example, in a patient with a postoperative ileus or with neurogenic bowel issues who complains of constipation, bloating, absence of flatulence, and abdominal discomfort. In this instance, the objective of manual treatment would be to address sympathetic outflow to the colon; possible paraspinal inhibition to the thoracolumbar area could be appropriate to initiate bowel activity by restricting viscerosomatic stimulus to the bowel.

Metabolic-energy model

The metabolic-energy model takes into consideration the patient’s energy expenditure and ability to adapt to physiologic stress. An example might be a patient with chronic disease (eg, systolic heart failure) whose disease makes him or her more likely to decompensate if pneumonia developed than someone who did not have this baseline chronic issue would be. In such a situation, a goal of manipulative treatment might be to address the impact of pneumonia as follows:

• Addressing thoracic cage dysfunction and enhancing respiratory function
• Inhibiting sympathetic outflow to increase blood supply to lung tissue
• Promoting lymphatic return to reduce congestion

Aiding the resolution of pneumonia will reduce the demands on the failing heart.

Behavioral model

A patient with recurrent tension headaches might benefit from the behavioral model, which takes the patient’s mental and emotional status into consideration. In a hypothetical patient who is under significant stress and whose headaches are worsening in intensity and frequency, assessment and treatment of dysfunctions at the occipital-atlas junction, the suboccipital muscles, cranial bones, and the cervical vertebrae and musculature can improve structure, enhance autonomic regulation, address metabolic demands of muscles, and augment blood flow and lymphatic drainage. Much can be done structurally through manipulation to address the effects of stress, even if the causative factor cannot be treated.

Hypothesis of action of manipulation

The overriding mechanism by which manipulative techniques relieve pain is not fully understood. A simple categorization separates treatments into two broad types as follows:

• Treatments that mechanically lengthen tight soft tissues
• Treatments that alter the firing rate of inappropriately shortened muscles to achieve relaxation or ease

Either of these treatment techniques eliminates hypomobility of an offending segment if soft tissue is lengthened or the muscle is relaxed sufficiently. Functional, muscle energy, (most) myofascial release, and counterstrain techniques, using small forces, can work only on neuroreflexive alteration of muscle activity. Direct-thrust and articulatory techniques involve larger forces and, presumably, are able to stretch and elongate tissue.

Restricted motion arises from abnormal muscle contraction and shortened or stiffened soft tissues. All forms of manipulation interfere with abnormal muscular contraction, either by producing afferent stimuli that attenuate hyperexcitable, gamma-efferent systems or by eliminating proprioceptive input that stimulates the gamma-efferent system.

Thrust and, possibly, articulatory and isometric techniques stimulate Golgi tendon organ input. Articulatory and isometric techniques may elicit permanent lengthening of collagenous tissue by inducing a permanent set with repeated stretching. Direct-thrust techniques result in high stress levels and probably in high strain levels in soft tissues over a short period of time. Nonuniform distribution of strain may develop, leading to localized tissue injury and subsequent healing with permanent elongation, with the net result being that vertebrae regain normal motion play; the forces needed to produce motion then are normalized.

Facet malposition or malfunction can be influenced directly with manipulation by passive joint motion. A bulging disk may be reduced or normalized by manipulation. The change in proprioceptive input to the spinal cord may close the gate on pain or remove abnormal, facilitating proprioceptive input.

Use of manipulation by physiatrists

The goals of manipulation are to restore or optimize biomechanical function by improving motion, thereby facilitating mobility, minimizing pain, and increasing the patient's overall level of wellness.

Scientific evidence for the efficacy of manipulation has been mounting. General acceptance of the utility of manipulation in acute low back pain and other forms of musculoskeletal pathology has resulted in recommendations that manipulation be directed toward restoration of normal motion, reduction of pain, and overall increase of physical activity. There is also increasing evidence to support the use of manipulation in combination with other modalities to optimize the return of function.

A study by Childs et al compared the use of exercise as a standalone therapy with the employment of spinal manipulation in combination with an exercise program, in patients suffering from low back pain. ^[47] Improvements in disability and pain were, to a statistically significant degree, greater in the patients who received both therapies than in those in the low-stress aerobic and lumbar spine–stabilizing exercise group.

Subsequent literature reviews examining the use of manipulation in treating pain in the cervical and lumbar regions also supported its use. Bronfort et al found moderate evidence to support the use of spinal manipulation and mobilization in the treatment of chronic low back pain, stating that such treatment is "at least as effective as other efficacious and commonly used interventions." ^[48] Li et al concluded that when combined with exercise, soft-tissue manipulation for lumbar muscle strain is more significant. ^[49]

In a comprehensive literature review of nonsurgical interventions for the treatment of patients with whiplash-associated disorder (WAD) and for other neck disorders with or without trauma, ^[50] Hurwitz et al found that among the patients studied, treatment with mobilization and exercises seemed to be more effective than did treatment with the usual types of care or physical modalities.

Hurwitz et al also found evidence that for non-WAD neck disorders, in the absence of radicular signs or symptoms, it was more beneficial to treat patients with manual (manipulation or mobilization) and exercise interventions, low-level laser therapy, and perhaps acupuncture than to provide them with either sham or alternative treatments, or with no intervention at all. ^[50]

However, among the more successful "active" treatments, none was found to have a clear benefit over the others on either a short- or long-term basis. ^[50] According to the report, for "WAD and neck disorders without trauma, the evidence favors supervised exercise sessions with or without manual therapy over usual or no care. Of the manual therapies, manipulation and mobilization yield comparable clinical outcomes."

Prescription of manipulation

Referral of a patient to another practitioner for manipulation requires a prescription, the contents of which may be communicated through conversation between the practitioners. Manipulative care also may be included as a portion of a general strengthening, conditioning, and musculoskeletal educational program.

Practitioners to whom a referral for manipulation may be made—after careful history, physical examination, and structural assessment by a physician—include not only osteopathic physicians but also other types of professionals, including (but not limited to) chiropractors, massage therapists (for massage only), and physical therapists and athletic trainers who have been additionally trained in manipulation. If one seeks the combination of full physician training with well-developed manipulative skills, in the United States, the optimal choice would be a physician (DO or MD) with either extensive training and expertise in manipulation or board certification by the American Osteopathic Association.

The specific region to be manipulated, potentially suggested techniques, and discussion of any medical issues, considerations, or side effects also must be a part of the prescription. Include patient age, precautions, diagnosis, treatment recommendations, frequency, duration, and other comments in all prescriptions for manipulation.

Follow-up patient examination is essential. If treatment has been unsuccessful, consider reformulation of the diagnosis or of the therapeutic manipulative approach. If manipulation procedures are producing discomfort lasting more than 8 hours, consider changing to a less invasive, or possibly an indirect, technique.

The manipulative technique used in any intervention is determined by the time course of the problem and the patient's age and general physical condition, as well as past medical history, the presence of any contraindications, and the practitioner's expertise and training. These considerations underscore the need for a careful history and physical examination, structural examination, and functional diagnosis.

A musculoskeletal problem amenable to manipulation must be identified in order for this approach to be effective. The identification of the source of pain is particularly important for patients with subacute or chronic pain.

Note also that complete eradication of pain is rare. This fact may lead patients to become dependent on manipulation. Having well-defined biomechanical end points of treatment (eg, normal ROM and tissue texture) helps to formulate an effective end to treatment. Especially in the patient with chronic pain, manipulation should be directed toward obtaining an optimalbiomechanicalmusculoskeletal condition as quickly as possible.

Research relating to manipulation

Numerous clinical trials of spinal manipulative treatment have been summarized in the literature. Further, manipulative treatment has been the subject of multiple international consensus meetings. Trials have attempted to improve knowledge by comparing thrust with nonthrust (ie, direct with indirect) techniques and joint-specific with non-joint-specific manual therapies, by varying the frequency and intensity of interventions and by comparing different types of joint-specific manipulation techniques.

Studies in the literature have varied in terms of research design, criteria for improvement, time of evaluation, and techniques examined. The wide variations among studies have made blinded reviews and objective meta-analysis very difficult. ^[51]

Anatomy and physics of manipulation

Understanding of the biomechanics of direct-thrust manipulation has significantly advanced. Indirect (ie, nonthrust) manipulation has been studied less. The external mechanical forces involved, the duration of the application of those forces, and the gross anterior/posterior displacements have been measured in human subjects, and relative displacements have been measured in cadaver studies. Study of internal forces and relative displacements of vertebral bodies resulting from applied forces has not been performed.

Some research has been conducted on the neurologic and neuromuscular responses to direct-thrusting procedures; however, little has been done to study other types of manipulative therapies in terms of biomechanical parameters or physiologic responses to them.

What has been learned about pain and mechanoreceptors, spinal cord physiology, and normal spinal biomechanics since the late 20th century has allowed this information to be applied and has facilitated contributions to the understanding of manual medicine and the treatment of somatic dysfunction. Knowledge about small tissue strains now is being accumulated and assimilated into manual medicine thinking.

Two primary areas of research development and scholarly inquiry that relate to manual medicine at this time are the objective measurement of somatic dysfunction in patients and the examination of the association of somatic dysfunction with acute and chronic pain. Further inquiry also is warranted into questions concerning mechanism, efficacy, and (in the current era of health care) cost containment.