The fibers of the muscle converge into a strong flattened tendon that inserts on the lateral surface of the greater trochanter. More specifically, the muscle's tendon inserts into an oblique ridge that runs downward and forward on the lateral surface of the greater trochanter. Before the insertion the fibers cross from anterior to posterior and vice versa.[1]
Relations
A bursa, the Bursa trochanterica m. glutaei medii, separates the tendon of the muscle from the surface of the trochanter over which it glides.[2] The deep surface of the gluteus medius is in relation to the gluteus minimus.[3]
Variations
The posterior border may be more or less closely united to the piriformis, or some of the fibers end on its tendon.
Function
The anterior part acting alone helps to flex and internally rotate the hip.
The posterior part acting alone helps to extend and externally rotate the hip.
The anterior and posterior parts working together abduct the hip and stabilize the pelvis in the coronal plane.[4]
Most of the muscle inserts behind the centre of rotation of the hip. However, its function changes in different positions of the femur. For example: If the leg is flexed, the whole muscle will flex.[5]
The posterior fibres of gluteus medius contract to produce hip extension, lateral rotation and abduction. During gait, the posterior fibres help to decelerate internal rotation of the femur at the end of swing phase.
Together with the gluteus minimus and other short pelvi-trochanteric muscles it centers and stabilises the hip. Thus, its preservation and the accurate anatomical reconstruction of the femoral offset and anteversion is of quintessential importance for the result of surgical hip replacement.[6]
Position of gluteus medius muscle (shown in red). Hip bone is shown in semi-transparent.
Origin and attachment areas.
Origin zone at the ilium.
Attachment zone at the trochanter major.
Attachment zone at the trochanter major.
The fibers of the gluteus medius cross from anterior to posterior and vice versa before its insertion at the greater Trochanter. The iliotibial tract has been partially removed.
Structures surrounding right hip-joint.
Gluteus medius muscle (shown in green text)
Adduction and abduction of the femur. The centre of rotation of the hip has been marked.
^Hermann Braus, Curt Elze: Anatomie des Menschen. Ein Lehrbuch für Studierende und Ärzte. Erster Band. Bewegungsapparat. 3. Auflage. Julius Springer, Berlin 1954. Digitalisat der Universität Heidelberg. p. 459 – 461.
^Hahn von Dorsche, Herwig; Dittel, Reinhard (2006). Anatomie des Bewegungssystems (in German) (2nd ed.). Bad Hersfeld: Neuromedizin Verlag. pp. 269, 277–278, 289–290. ISBN978-3-930926-18-3.
^Schünke, M., Schulte, E., Schumacher, U., Ross, L. M., & Lamperti, E. D. (2006). Thieme atlas of anatomy. Stuttgart: Thieme. page 424
^Siegfried Mollier: Plastische Anatomie. Die konstruktive Form des menschlichen Körpers. Bergmann, München 1924.
^Adalbert Kapandji: Funktionelle Anatomie der Gelenke. Übersetzt von Jürgen Koebke (Erstausgabe in 3 Bänden, Ferdinand Enke, 1984). Deutschsprachige Gesamtausgabe durch Stefan Rehart. Thieme, Stuttgart 2016. Band 2, S. 50 – 57, 66 – 69, 74 – 75.
^Gogu, Swetha; Gandbhir, Viraj N. (2024), "Trendelenburg Sign", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID32310447, retrieved 2024-09-29