The gluteus medius, one of the three
gluteal muscles
The gluteal muscles, often called glutes are a group of three muscles which make up the gluteal region commonly known as the buttocks: the gluteus maximus, gluteus medius and gluteus minimus. The three muscles originate from the ilium and sa ...
, is a broad, thick, radiating
muscle. It is situated on the outer surface of the
pelvis.
Its posterior third is covered by the
gluteus maximus, its anterior two-thirds by the
gluteal aponeurosis
The gluteal aponeurosis is a fibrous membrane, from the fascia lata, that lies between the iliac crest and the superior border of the gluteus maximus
The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost o ...
, which separates it from the
superficial fascia and integument.
Structure
The gluteus medius muscle starts, or "originates", on the outer surface of the
ilium between the
iliac crest
The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
Structure
The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the poster ...
and the
posterior gluteal line
The gluteal lines are three curved lines outlined from three bony ridges on the exterior surface of the ilium in the gluteal region. They are the anterior gluteal line; the inferior gluteal line, and the posterior gluteal line.
The gluteus mini ...
above, and the
anterior gluteal line below; the gluteus medius also originates from the
gluteal aponeurosis
The gluteal aponeurosis is a fibrous membrane, from the fascia lata, that lies between the iliac crest and the superior border of the gluteus maximus
The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost o ...
that covers its outer surface.
The fibers of the muscle converge into a strong flattened
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
that inserts on the lateral surface of the
greater trochanter
The greater trochanter of the femur is a large, irregular, quadrilateral eminence and a part of the skeletal system.
It is directed lateral and medially and slightly posterior. In the adult it is about 2–4 cm lower than the femoral head.Stan ...
. More specifically, the muscle's tendon inserts into an oblique ridge that runs downward and forward on the lateral surface of the greater trochanter.
Relations
A
bursa separates the tendon of the muscle from the surface of the trochanter over which it glides.
Variations
The posterior border may be more or less closely united to the
piriformis
The piriformis muscle () is a flat, pyramidally-shaped muscle in the gluteal region of the lower limbs. It is one of the six muscles in the lateral rotator group.
The piriformis muscle has its origin upon the front surface of the sacrum, and in ...
, or some of the fibers end on its tendon.
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.
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.
[Schünke, M., Schulte, E., Schumacher, U., Ross, L. M., & Lamperti, E. D. (2006). Thieme atlas of anatomy. Stuttgart: Thieme. page 424]
Clinical significance
Dysfunction of the gluteus medius or the
superior gluteal nerve can potentially be indicated by a positive
Trendelenburg's sign
Trendelenburg's sign is found in people with weak or paralyzed abductor muscles of the hip, namely gluteus medius and gluteus minimus. It is named after the German surgeon Friedrich Trendelenburg. It is often incorrectly referenced as the Tr ...
.
Additional images
File:Gluteus medius muscle - animation04.gif, Position of gluteus medius muscle (shown in red). Hip bone
The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the ilium, isch ...
is shown in semi-transparent.
File:Gray344.png, Structures surrounding right hip-joint.
File:Slide2hh.JPG, Gluteus medius muscle (shown in green text)
See also
*
Trendelenburg gait
Trendelenburg gait, named after Friedrich Trendelenburg, is an abnormal gait. It is caused by weakness or ineffective action of the gluteus medius muscle and the gluteus minimus muscle.
Gandbhir and Rayi point out that the biomechanical action ...
References
External links
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{{DEFAULTSORT:Gluteus Medius Muscle
Hip abductors
Hip lateral rotators
Hip medial rotators
Muscles of the gluteus
Hip muscles
Muscles of the lower limb