Gluteus MediusEdit
The gluteus medius is a thick, fan-shaped muscle on the lateral aspect of the hip. It is one of the principal gluteal muscles, lying just below the iliac crest and over the greater trochanter of the femur. Its robust tendon contributes importantly to hip abduction and to stabilizing the pelvis during single-leg stance, such as when walking. In everyday function, the gluteus medius works in concert with the gluteus minimus and the tensor fasciae latae to position the thigh and maintain pelvic balance during locomotion. The muscle is innervated by the Superior gluteal nerve and supplied by branches of the superior gluteal artery.
This muscle’s role extends beyond simple abduction. The anterior fibers can assist in medial rotation and flexion of the hip, while the posterior fibers contribute to lateral rotation and extension. Because it acts as a pelvis stabilizer, weakness or injury to the gluteus medius can lead to gait abnormalities and pelvic drop during walking, a classic sign known as the Trendelenburg sign in clinical examination.
Anatomy
Originating from the outer surface of the ilium between the anterior and posterior gluteal lines, the gluteus medius inserts onto the lateral surface of the greater trochanter of the femur. Its broad attachment spreads into a tendon that blends with nearby structures of the hip region. The muscle lies superficial to the gluteus minimus and deep to the gluteus maximus in most regions, forming a key part of the lateral hip contour.
- Origin: ilium (outer surface, between anterior and posterior gluteal lines)
- Insertion: greater trochanter (lateral surface)
Innervation and vascular supply are essential for function: - Innervation: Superior gluteal nerve (L4–S1) - Blood supply: branches of the superior gluteal artery
Function and biomechanics
The gluteus medius is best known for its primary action: abduction of the thigh at the hip. This abduction is crucial for maintaining a level pelvis during the stance phase of gait and for allowing smooth, coordinated movement of the lower limb. The anterior portion of the muscle can assist with hip flexion and internal rotation, whereas the posterior portion can assist with hip extension and external rotation. The integrated action of the gluteus medius with the gluteus minimus and tensor fasciae latae helps stabilize the pelvis across a range of hip positions and during dynamic activities such as walking, running, and climbing stairs.
During gait, the gluteus medius counters the tendency of the pelvis to drop on the swinging side. Strong remodeling or training of this muscle supports efficient locomotion and reduces compensatory movements that can place additional stress on the lower back and knee.
Clinical significance
Weakness, injury, or pathology of the gluteus medius can produce noticeable functional deficits and pain. Clinically, the most recognizable consequence of diminished gluteus medius strength is a positive Trendelenburg sign, where the pelvis tilts downward on the side opposite the weakness during single-leg weight bearing.
- Tendinopathy and tears: The gluteus medius tendon can be stressed by repetitive hip movement or acute injury, leading to pain over the lateral hip and difficulties with abduction. Greater trochanteric pain syndrome is one related condition that can involve the gluteus medius tendon or its surrounding structures.
- Nerve injury: Damage to the Superior gluteal nerve—for example, in certain hip surgeries or traumatic injuries—can produce weakness of the gluteus medius and related muscles, with gait disturbances as a result.
- Imaging and diagnosis: Evaluation often relies on clinical examination supplemented by imaging such as MRI or ultrasound to assess tendon integrity, muscle bulk, and nearby bony structures.
Management typically emphasizes targeted rehabilitation and strengthening of hip abductors, including the gluteus medius, to restore pelvic stability and improve pain. Central elements include progressive resistance training, neuromuscular re-education, and activity modification. In persistent cases, interventions such as corticosteroid injections or, rarely, surgical repair or debridement of the tendon may be considered, sometimes in conjunction with another hip procedure. Rehabilitation strategies frequently incorporate guidance from physical therapy physical therapy specialists and, when indicated, imaging-guided procedures.