eMedicine Specialties > Sports Medicine > Lower Limb

Iliopsoas Tendinitis

Joseph P Garry, MD, Director of Sports Medicine and Sports Medicine Fellowship, Department of Family Medicine, Associate Professor of Family Medicine and Exercise & Sport Science, East Carolina University Brody School of Medicine
Kathleen M Walsh, EdD, ATC-L, Director of Sports Medicine and Athletic Training, Department of Health Education, Assistant Professor, East Carolina University
Contributor Information and Disclosures

Updated: Aug 29, 2006

Introduction

Background

Hip and pelvis injuries represent 2-5% of all sports injuries. Among these injuries, groin pain is the most common finding. The most common sports-related injuries in the hip, pelvis, and thigh area are musculotendinous, (eg, quadriceps strain, adductor tendinitis) and, less commonly, iliopsoas tendinitis. Iliopsoas tendinitis and iliopsoas bursitis are closely interrelated because inflammation of one inevitably causes inflammation of the other, due to their close proximity. Therefore, these 2 conditions are essentially identical in terms of presentation and management.

In basic terms, iliopsoas tendonitis is an inflammation of the tendon or area surrounding the tendon. Major causes of iliopsoas tendinitis are acute trauma and overuse resulting from repetitive hip flexion.

Frequency

United States

No data on prevalence of iliopsoas tendinitis exists. Despite this, it is a relatively uncommon and poorly recognized cause of anterior hip or groin pain. Iliopsoas tendinitis is noted to affect young adults more commonly, with a slight female predominance.

Functional Anatomy

The pelvis links the trunk and lower extremities. The hip, a ball and socket joint, allows for 3 degrees of freedom. Range of motion (ROM) of the hip includes approximately 120° of flexion, 20° of extension, 40° of abduction, 25° of adduction, and 45° each of internal rotation and external rotation. The resting position of the hip is considered to be 30° of flexion and 30° of abduction.

The psoas and iliacus muscles originate from the lumbar spine and pelvis, respectively, and are innervated by the upper lumbar nerve roots (ie, L1, L2, L3). These muscles converge to form the iliopsoas muscle, which inserts onto the lesser trochanter of the proximal femur as the iliopsoas tendon. The psoas major tendon exhibits a characteristic rotation through its course, transforming its ventral surface into a medial surface. The iliac portion of this tendon has a more lateral position, and the most lateral muscle fibers of the iliacus muscle insert onto the lesser trochanter without joining the main tendon.

The iliopsoas muscle passes anterior to the pelvic brim and hip capsule in a groove between the anterior inferior iliac spine laterally and iliopectineal eminence medially. The musculotendinous junction is consistently found at the level of this groove. The iliopsoas muscle functions as a hip flexor and external rotator of the femur.
 
An ilio-infratrochanteric muscular bundle has been described, which likely relates to the iliopsoas tendon. This muscular bundle arises from the interspinous incisure and anterior inferior iliac spine (above the origin of the rectus femoris muscle), courses along the anterolateral edge of the iliacus muscle, and inserts without a tendon onto the anterior surface of the lesser trochanter. The iliopsoas bursa lies between the musculotendinous junction and the pelvic brim. This bursa is the largest in the body and may extend proximally into the iliac fossa or distally to the lesser trochanter. Communication between this bursa and the hip joint occurs in approximately 15% of all adults.

A variety of terms have been used to describe and classify tendon injuries. Tendonitis is typically associated with an acute injury through which failure of the tendon fibers and disruption of the vascularized peritendinous connective tissue produces an acute inflammatory response within the tendon. Tendinitis may be acute, subacute, or chronic, depending on the duration of symptoms.

Peritendinitis is a condition in which an acute injury produces an inflammatory response in only the soft tissue surrounding a tendon, without disruption of the tendon fibers. On the other hand, tendinosis is often associated with chronic microtrauma to the tendon, such as repetitive overload. In the case of tendinosis, fiber failure tends to be characterized by intrasubstance failure, compared with peritendinous disruption, which occurs in tendinitis. Microscopic findings in tendinosis include fibrillar degeneration, angiofibroblastic proliferation, myxoid degeneration, fibrosis, and, occasionally, chronic inflammation.

Sport Specific Biomechanics

Acute injury and overuse injury are the 2 main causes of iliopsoas tendinitis. The acute injury typically involves an eccentric contraction of the iliopsoas muscle, but also may be due to direct trauma. Overuse injury may occur in activities involving repeated hip flexion or external rotation of the thigh. Activities that may predispose to iliopsoas tendinitis include dancing, ballet, resistance training, rowing, running (particularly uphill), track and field, soccer, and gymnastics.

During the adolescent growth spurt, the hip flexors tend to become relatively inflexible. This inflexibility can lead to problems in younger athletes because stress placed on the iliopsoas musculotendinous unit increases and general biomechanics are altered. Tightness of the iliopsoas, tensor fascia lata, or rectus femoris can lead to inhibition of the gluteus maximus, allowing for an anterior pelvic tilt. This in turn leads to adverse affects on the kinetic chain. Excessive anterior tilt can lead to increased lumbar lordosis with resultant stress on the lower lumbar discs, facet joints, and sacroiliac joints and may result in increased knee flexion at heel strike and during midstance phases of the gait cycle. The subsequent increase in eccentric load across the knee extensor mechanism may result in patellar tendon injuries. With increased knee flexion, compressive forces at the patellofemoral contact surface increase and may predispose to patellofemoral problems.

Clinical

History

Patients often present with complaints of an insidious onset of anterior hip or groin pain. As in other cases of tendinitis, initially the patient may note pain after onset of aggravating activity with resolution soon thereafter. This condition may progress to pain that persists during activity but subsides with rest, and eventually to pain during activity and at rest. The average time from initial onset of symptoms to diagnosis has been noted to range from 32-41 months.

• At presentation, patients may note pain with specific sports-related activities, such as jogging, running, or kicking. Pain with simple activities, such as putting on socks and shoes, rising from a seated position with the hips flexed for some time, walking up stairs or inclines, or brisk walking may be reported.
• Pain may radiate down the anterior thigh toward the knee.
• Reports of an audible snap or click in the hip or groin commonly are reported and associated with internal snapping hip syndrome.
• Patients may report anterior knee pain consistent with patellar tendinitis or patellofemoral dysfunction, which may be the result of a tight iliopsoas muscle.

Physical

Physical examination should focus on complete examination of the abdomen, hip, and groin. In females, a complete pelvic examination also should be considered.

• Inspection
• • The hip may be held in slight flexion and external rotation to ease tension on the musculotendinous unit.
  • Gait may demonstrate a shortened stride length on the affected side and increased knee flexion in the heel strike and midstance phases.
     
• Palpation
• • An anterior pelvic tilt may be appreciated due to subsequent tightening of the iliopsoas muscle.
  • Direct deep palpation to the area of the femoral triangle, which is bordered superiorly by the ilioinguinal ligament, medially by the adductor longus muscle, and laterally by the sartorius muscle, results in direct palpation of the iliopsoas musculotendinous junction.
  • Tenderness over the iliopsoas tendon's insertion may be noted by palpating the lesser trochanter under the gluteal fold with the patient lying in a prone position.
     
• Functional testing
• • Functional testing includes resisted hip flexion at 15° with palpation of the psoas muscle below the lateral half of the inguinal ligament.
  • The patient also may be asked to sit with knees extended and subsequent elevation of the heel on the affected side. Pain caused by this maneuver (a positive Ludloff sign) is consistent with an iliopsoas tendinitis because the iliopsoas is the sole hip flexor activated in this position.
  • The snapping hip sign or extension test also may be performed. Start with the affected hip in a flexed, abducted, and externally rotated position (knee is flexed for ease of testing), and passively move the hip into extension. This may result in an audible snap or palpable impulse over the inguinal region. Pain associated with this maneuver is highly suggestive of iliopsoas tendinitis or bursitis.

Causes

The 2 most common causes of iliopsoas tendinitis are acute injury and overuse injury. The acute injury often involves eccentric contraction of the iliopsoas muscle or rapid flexion against extension force/resistance but may less commonly result from direct trauma. The overuse phenomenon may occur in any activity resulting in repeated hip flexion or external rotation of the femur.

• Among dancers, a narrow bi-iliac width, greater abduction, decreased lateral rotation, and greater strength in the lateral rotators have been described more commonly with snapping hip syndrome, which is related to iliopsoas tendinitis.
• Rheumatoid arthritis may be a cause of iliopsoas bursitis.

References

• Contusions
• Femoral Head Avascular Necrosis
• Femoral Neck Stress Fracture
• Groin Injury
• Hip Fracture
• Hip Overuse Syndrome
• Lumbosacral Disc Injuries
• Lumbosacral Radiculopathy
• Osteitis Pubis
• Slipped Capital Femoral Epiphysis
• Snapping Hip Syndrome

• Foot, Ankle, Knee, and Hip Center
• Sports Injury Center
• Arthritis Center
• Tendinitis Overview
• Tendinitis Causes
• Tendinitis Symptoms
• Tendinitis Treatment
• Bursitis Overview