AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Background

An adductor (groin) strain is a common problem among many individuals who are physically active, especially in competitive sports. The most common sports that put athletes at risk for adductor strains are football, soccer, hockey, basketball, tennis, figure skating, baseball, horseback riding, karate, and softball.

Hip adductor injuries occur most commonly when there is a forced push-off (side-to-side motion). High forces occur in the adductor tendons when the athlete must shift direction suddenly in the opposite direction. As a result, the adductor muscles contract to generate opposing forces.

One common cause of adductor strain in soccer players has been attributed to forceful abduction of the thigh during an intentional adduction. This type of motion occurs when the athlete attempts to kick the ball and meets resistance from the opposing player who is trying to kick the ball in the opposite direction. To a lesser extent, jumping also can cause injury to the adductor muscles, but, more commonly, it involves the hip flexors. Overstretching of the adductor muscles is a less common etiology.

Pathophysiology

The hip adductors are a powerful muscle group. They consist of the adductor magnus, minimus, brevis, and longus. The gracilis and pectineus muscles also are included. All of the adductor muscles are innervated by the obturator nerve (L2-L4) except the pectineus, which is innervated by the femoral nerve (L2-L4). The adductor magnus also is innervated by the tibial nerve (L4-S3).

• Adductor magnus/minimus
  • Origin - Inferior pubic ramus/ischial tuberosity
  • Insertion - Linea aspera/adductor tubercle
• Adductor brevis
  • Origin - Inferior pubic ramus
  • Insertion - Linea aspera/pectineal line
• Adductor longus
  • Origin - Anterior pubic ramus
  • Insertion - Linea aspera
• Gracilis
  • Origin - Inferior symphysis/pubic arch
  • Insertion - Proximal medial tibia
• Pectineus
  • Origin - Pectineal line of pubis
  • Insertion - Pectineal line of femur

The musculotendinous junction is thought to be the most common site of injury in a muscle strain. Studies in muscle physiology demonstrate that the sarcomeres near the junction are less elastic than those found at the central portion of the muscle. The musculotendinous junction is likely to be vulnerable to indirect muscle injury that results from excessive force. Muscle strain injury has been characterized as occurring in response to forcible stretching of a muscle, most commonly while the muscle is activated. When the muscle is activated, muscle strain injury occurs, most often during eccentric (lengthening) contraction.

Frequency

United States

Muscle strain is the most frequent injury observed in sports. Up to 30% of office visits in a primary care sports medicine practice are attributed to muscle strain.

International

Scandinavian soccer studies have reported groin injury rates of 10-18 injuries per 100 soccer players each year. Lovell studied 189 cases of chronic groin pain in which he attributed 30% to adductor injuries. The Renstrom and Peterson study found the adductor longus was responsible for 62% of groin injuries. Injuries to the groin account for 5% of all soccer injuries and 2.5% of karate injuries.

Mortality/Morbidity

Improper management of acute adductor strains or returning to play before pain-free sport-specific activities can be performed may lead to chronic injury.

• Chronic adductor strain
  • Generally, symptoms are more diffuse with typical complaints of pain and stiffness in the groin region in the morning and at the beginning of athletic activity. Pain and stiffness often resolve after a period of warming up but often recur after athletic activity.
  • Typical findings include tenderness at the origin of the adductor longus and/or the gracilis located at the inferior pubic ramus and pain with resisted adduction.
• Improper management of acute adductor strains
  • According to a study by Renstrom and Peterson, 42% of athletes with groin muscle-tendon injuries could not return to physical activity after more than 20 weeks following the initial injury.
  • This prolonged length of time seems to indicate the importance of proper management of these injuries in the acute stage.

Race

No specific race has been identified as having a higher prevalence rate for adductor injuries in the literature than any other race.

Sex

No difference in the incidence of adductor injuries between males and females is found in the literature.

Age

As with other musculotendinous injuries, increased age is related to elevated risk for strains due to reduced elasticity of connective tissue.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

Groin pain can represent a number of different diagnoses, and all differential diagnoses should be kept in mind when assessing the patient. Obtain information about the mechanism of injury and loss of function, as well as about the location, quality, duration, and severity of pain. The aggravating and alleviating factors also should be noted.

• Location: Usually, pain is described at the site of the adductor longus tendon proximally, especially with rapid adduction of the thigh. As the injury becomes more chronic, pain may radiate distally along the medial aspect of the thigh and/or proximally toward the rectus abdominis.
• • Exercise-induced medial thigh pain over the area of the adductors, especially after kicking and twisting, may indicate obturator neuropathy.
  • Pain at the symphysis pubis or scrotum may be more consistent with osteitis pubis.
  • Conjoined tendon lesions present as pain that radiates upward into the rectus abdominis or laterally along the inguinal ligament. Exquisite tenderness is present at the site of the injury.
• Quality: Acute injuries are described as a sudden ripping or stabbing pain in the groin. Chronic injuries are described as a diffuse dull ache.
• Duration: Initial intense pain lasts less than a second. This initial pain is soon replaced with an intense dull ache.
• Severity of pain: Pain severity can vary with different patients.
• Loss of function: True loss of function is not observed unless a grade 3 tear is present. In the case of a severe tear, loss of hip adduction occurs. Loss of function also should alert the physician to possible nerve involvement (obturator nerve entrapment).
• Mechanism of injury: Rapid adduction of the hip against an abduction force (eg, changing direction suddenly in tennis), acute forced abduction that puts an unusual stretch on the tendon (eg, a rugby tackle), and a sudden acceleration in sprinting are the most common mechanisms of injury.

Physical

• The acute adductor strain commonly occurs at the musculotendinous junction.
• Tenderness, swelling, and ecchymosis can be observed at the superior medial thigh. Sometimes, a defect in the muscle can be palpated.
• Pain is noted with resisted adduction and full passive abduction of the hip.
• A pure hip adductor strain can be distinguished from combination injuries involving the hip flexors (ie, iliopsoas, rectus femoris) by having the patient lie in the supine position. If more discomfort is reproduced with resistive adduction when the knee and hip are extended than if the hip and knee are flexed, a pure hip adductor strain can be assumed.
• Physical findings can help distinguish adductor strains from other causes of groin pain such as the following:
• • Iliopsoas strain: Hip flexion against resistance is painful. Tenderness is difficult to localize because the insertion of the iliopsoas is deep.
  • Osteitis pubis: Tenderness of the symphysis pubis and possible loss of full rotation of one or both hip joints are noted.
  • Conjoined tendon lesions (ie, sportsman's hernia): Exquisite tenderness upon palpation at the inguinal canal. Having the patient cough reproduces pain.
  • Obturator neuropathy: Adductor muscle weakness, muscle spasm, and paresthesia over the medial aspect of the distal thigh may be present. Loss of adductor tendon reflex with preservation of other muscle stretch reflexes often is observed. A positive Howship-Romberg sign (medial knee pain induced by forced hip abduction, extension, and internal rotation) sometimes is observed.

Causes

Injury to the hip adductors most commonly occurs following forced push-off (side-to-side motion). An extreme amount of stress is placed on the adductor tendons when, because of the athlete's momentum, a large amount of force is applied to one side in the sagittal plane and the adductor muscles must contract rapidly to shift the force to the opposite direction. Other causes include forceful abduction of the thigh during an intentional adducting motion and jumping. Jumping is involved to a lesser extent than abduction and is associated more commonly with hip flexor strains. Overstretching of the adductor tendons is a much less common cause.

• The adductor tendons have a small insertion area that attaches to the periosteum-free bone. This transitional zone is characterized by a poor blood supply and rich nerve supply, explaining the high level of perceived pain and poor healing characteristics of adductor strains.
• Failure to stretch the adductor muscles properly puts them at increased risk for injury. Weakness of the adductor muscles is a common problem that puts these muscles at increased risk for injury, as the load to failure is much less in weaker muscles.
  

DIFFERENTIALS

Section 4 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Other Problems to be Considered

Iliopsoas bursitis
Iliopsoas tendinitis
Rectus femoris tendinitis
Urological disorders
Sacroiliac dysfunction
Nerve entrapment
Malignant/nonmalignant tumors
Sportsman's hernia
Avulsion fracture
Hip disorders (eg, osteoarthritis [OA], degenerative joint disease [DJD], slipped capital femoral epiphysis [SCFE])
Gastrointestinal disorders
Sexually transmitted diseases
Gynecological complaints

WORKUP

Section 5 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• Urinalysis should be considered only if a genitourinary cause is suggested.

Imaging Studies

• Radiographs of the symphysis pubis
• • Radiographs should be taken with the patient standing on one leg.
  • Radiographs are used to evaluate for osteitis pubis with extrusion of the fibrocartilaginous disk and degeneration of adjacent bony margins.
• Ultrasound
• • Ultrasound may indicate abnormal findings, such as sonolucent areas and tendon fiber discontinuity that can be indicative of injury to 3 different sites, including: (1) the tendon insertion, (2) the tendon itself, and (3) the musculotendinous junction.
  • Ultrasound can be used to evaluate a mass.
• CT scan/MRI: These imaging studies can be used to evaluate for complete and partial adductor muscle tears.
• Technetium Tc 99m: This test has been shown to assist the physician in the diagnosis of osteitis pubis.

Procedures

• Use of steroid injections is controversial in adductor strains.
• • The potential for tendon rupture exists if the steroid is injected into the tendon itself.
  • Renstrom advocates injection of local anesthetic with or without corticosteroids into the tendon periosteal area if conservative treatment has been unsuccessful for 2-4 months. This treatment should be combined with 1-2 weeks of rest from activity after injection.

TREATMENT

Section 6 of 11  

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• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Rehabilitation Program

Physical Therapy

The initial management of an adductor injury should include protection, rest, ice, compression, and elevation (PRICE). Painful activities should be avoided. The use of crutches during the first few days may be indicated to relieve pain.

Some authorities advocate that stretching in the acute phase may aggravate the condition and lead to a chronic lesion. Control of muscle spasms is important for rehabilitation. Spasms may be alleviated with medication and/or modalities (eg, ice, electrical muscle stimulation). Passive range of motion (PROM) exercises are initiated when they patient can perform them without pain. Active muscle exercises can be advanced slowly from isometric contractions without resistance to isometrics with resistance, progressing eventually to dynamic exercises when tolerated with little or no pain.

Strengthening abdominal and hip flexor muscles is an essential part of rehabilitation of groin injuries. Coactivation of the abdominal muscles and the adductor muscles is a useful and functional exercise. Completing many repetitions increases the endurance of the adductor muscles. A fatigued muscle/tendon complex is more vulnerable to injury. The patient should aim to progress gradually to 30-40 repetitions. Proprioceptive exercises are recommended, along with stretching, as well as an aquatic training program if accessible. After several days, heat and support bandages are recommended.

Grade I strain

• Modalities and pain-free hip stretching exercises can begin immediately.
• Pain-free progressive strengthening exercises also can be initiated immediately and can progress to include hip flexion (with knee straight and bent) and adduction.
• Therapy may be advanced to include the slide board, plyometrics (lateral sliding, lateral lunges [see Images 1-5], and X lunges [see Images 6-8]), and, finally, sport-specific functional drills.
• The athlete may not be required to miss competition time, depending on the severity of the injury.

Grade II strain

• Therapy should begin immediately with gentle pain-free active range of motion (AROM) exercises of the hip.
• Isometric exercises should be initiated as soon as the patient can perform them without pain.
• After 1 week, pain-free slide board exercises and plyometrics can be initiated.
• Soon after the first week, sport-specific functional drills can begin.
• An athlete with a grade II strain may miss 3-14 days of competition, depending on the severity of the injury.

Grade III strain (nonsurgical)

• PRICE plus a non–weight-bearing restriction for acute strains
• Rest for 1-3 days with continuous compression is appropriate.
• If surgery is not indicated, pain-free isometric exercises and slow, pain-free AROM exercises can be started between days 3 and 5.
• The athlete should continue to use crutches until normal pain-free ambulation is possible.
• Initiate pain-free stretching exercises, progressive resistive strengthening exercises (without pain), and proprioceptive neuromuscular facilitation (PNF) between days 7 and 10.
• Usually within 10 days after starting progressive resistive strengthening exercises, the patient should be able to perform pain-free slide board exercises and plyometrics and eventually advance to sport-specific functional activities.

Grade III (surgical): See Surgical Intervention.

Chronic strain:

• In the treatment of long-standing groin pain, rest, ice, massage, and therapeutic ultrasound have been recommended. Nonsteroidal anti-inflammatory drugs (NSAIDs) and steroid injections have been suggested, but no controlled trials have been published on the subject. Forceful adductor stretch under general anesthetic has been recommended. A careful monitored program with a total cessation of the sports activity is necessary for the chronic adductor injury to heal and become pain-free.
• This program should consist of isometric exercises, strengthening of the hip- and pelvis-stabilizing muscles, and proprioceptive training. No increase in pain should be experienced during or after the exercises. The load of the exercises gradually is increased. Specific strengthening of the adductor muscles then is implemented. Cycling can be used to maintain general conditioning. Running can begin only after the patient can perform these exercises at high intensity without pain. Sprinting and cutting activities then may follow. Sport-specific training is the final step before full return to sport. This part of the rehabilitation program may take 3-6 months.

Medical Issues/Complications

Chronic adductor strain

• Do not advance the athlete too quickly back to his/her sport, as the injury may become a chronic condition.
• Acute strains easily can become chronic strains if proper time is not allowed for healing. Chronic strains are much more difficult to manage.
  

Surgical Intervention

Surgery is indicated in acute strains only when there is rupture and in select chronic strains refractory to conservative treatment.

• Patient is in the supine position with the knee in 90° of flexion and the hip in 45° of flexion. The adductor longus tendon is identified. A skin incision is made. A discoloration of the tendon or a swelling indicates an old partial rupture. The tendon then is opened longitudinally. Occasionally, granulation tissue is found and excised. If there are no findings in the tendon, a tenotomy may be performed.
• • A tenotomy is described in an article by Martems et al. The region is infiltrated with lidocaine and epinephrine. A stab wound is made just underneath the adductor longus muscle, close to the os pubis. The insertion of the gracilis muscle and a portion of the adductor brevis are sectioned subcutaneously. The adductor longus tendon is left intact. A compression bandage then is applied for 24 hours. The patient may walk after 2 days and may resume running within pain limits 5 weeks postoperatively. The usual time period to return to unrestricted sports activities is 10-12 weeks. In this study, there was no loss of power in the surgical group compared with the control group.

Consultations

Review the Differentials for other etiologies for groin pain. Obtain consultations as appropriate to rule out differential diagnoses.

• Orthopedic surgery
• • If a mass is felt in the middle to upper thigh, the physician must consider a rupture at the distal musculotendinous junction. Tumor and hernia also should be ruled out. These conditions warrant a surgical consultation.
  • Obturator nerve entrapment should be suspected if there is exercise-induced medial thigh pain that starts at the origin of the adductor longus and radiates distally along the medial thigh. Denervation of the adductor muscles is seen on needle electromyogram (EMG). The treatment for obturator nerve entrapment is nonoperative with surgical neurolysis in recalcitrant cases.

MEDICATION

Section 7 of 11  

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• Follow-up
• Miscellaneous
• Multimedia
• References

The goals of pharmacotherapy in adductor strain are to reduce morbidity and prevent complications.

Drug Category: Cyclooxygenase type-2 inhibitors

Drug of choice (DOC) for this condition; in cases of severe pain, opioid analgesic agents may be prescribed. Muscle relaxants often are used to reduce muscle spasm after initial injury. Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeds is clearly less with COX-2 inhibitors than with traditional NSAIDs. Ongoing analysis of cost avoidance of GI bleeds will further define the populations that will find COX-2 inhibitors the most beneficial.

Drug Category: Nonsteroidal anti-inflammatory drugs

DOC for this condition; in cases of severe pain, opioid analgesic agents may be prescribed. Muscle relaxants often are used to reduce muscle spasm after initial injury.

Drug Category: Muscle relaxants

Indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute painful musculoskeletal conditions.

Drug Category: Acetamide local anesthetic

Used for local pain relief

FOLLOW-UP

Section 8 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Outpatient Care

• See Physical Therapy for a discussion of proper treatment guidelines following a groin strain.

Deterrence

• Thermal pants have been described to help prevent hamstring injury in rugby players. This observation probably is applicable to adductor injuries as well. Heat increases the extensibility of the collagen in the tendons. In a study by Nikolaou, load to failure was lower and mean stiffness was noted to be higher in cold muscle. This finding suggested that warm muscle may be protective.
• Elastic bandages have been used by athletic trainers to help give support to the adductor muscles after injury (see Image 11).
• Proper stretching and warming up is effective in preventing muscle strains. Adequate strengthening of the adductor muscles can prevent overload of the musculotendinous junction and is an important component of prevention. Strengthening of the abdominal muscles and lumbar muscles also is important.

Complications

• Proper treatment of an acute adductor strain is important to prevent complications and development of a chronic strain. If the athlete develops chronic symptoms, his/her length of rehabilitation becomes prolonged and return to participation is delayed. A common complication that results is a tight weak adductor muscle, which is prone to recurring strains when the athlete returns to activity.

Patient Education

• The patient needs to be educated on proper treatment following an acute groin injury. PRICE needs to be emphasized to ensure that swelling is reduced. In the acute stage, inform patients to avoid activities that may be harmful and promote increased blood flow to the adductor muscles, such as hot packs, hot showers, or massage. The athletic trainer and/or physical therapist should instruct the patient in proper exercises to rehabilitate the adductor muscles and enable the patient to return safely to participation in his/her sport or activity.
• For excellent patient education resources, visit eMedicine's Sports Injury Center. Also, see eMedicine's patient education article Muscle Strain.

MISCELLANEOUS

Section 9 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• As is the case in many injuries involving athletes, outside influence on the physician to return the athlete to play before he/she is medically ready can be a problem. The best interest of the player must take precedence in this situation. Returning a player with an adductor injury to his/her sport too quickly can have a detrimental effect on his/her future career. Adductor injuries have a tendency to become chronic when not properly treated.

MULTIMEDIA

Section 10 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Lateral lunge.
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Media file 2:  Lateral lunges.
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Media file 3:  Lateral lunges.
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Media file 4:  Lateral lunges.
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Media file 5:  Lateral lunges.
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Media file 6:  X lunges. Starting position.
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Media file 7:  X lunges.
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Media file 8:  X lunges. Back to the starting position.
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Media file 9:  X lunges.
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Media file 10:  Hip flexor stretch.
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Media file 11:  Hip flexor stretch, isolation of the rectus femoris.
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Media file 12:  Elastic bandage applied to give pain relief from an adductor strain.
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REFERENCES

Section 11 of 11

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

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Article Last Updated: Feb 21, 2007