The gluteus medius muscle is one of the three gluteal muscles — commonly referred to as butt muscles. Its action is to pull the thigh away from the middle of the body in order to keep the knee and muscles aligned properly. The muscle is also important in controlling the stability and level of the hip joint. If the gluteus medius muscle is weak then it can cause a number of different problems, including knee pain.
The origin of the gluteus medius is just below the crest of the ilium. From there it covers part of the outer hip before attaching to the femur. The innveration of the muscles is via the superior gluteal nerve. Due to its location — the muscle attaches to both the hip and leg — it is important for a number of activities such as stepping sideways.
Hip abduction is the primary purpose of the gluteus medius although it plays a part in a number of other actions. For example, the posterior part of the muscle is used to rotate the hip externally while the anterior fibers rotate it internally. When walking, the gluteus medius has the important role of supporting the body while it is standing on one leg, which helps to prevent the pelvis from being pulled downwards.
The Trendelenburg test is commonly used to test for weakness. If the pelvis falls downwards when a person stands on one leg then this is usually a sign of weakness. On the other hand, if the pelvis stays level then the gluteus medius is usually functioning correctly.
Stretching and strengthening the gluteus medius is important for a number of reasons. Not only does it reduce the risk of injury to the muscle itself but also to the hip and knee. Standing and laying abduction exercises are commonly used for strengthening the muscle along with “crab” walks. These can be performed by walking sideways with an exercise band providing tension.
There are two other gluteal muscles — the gluteus maximus and minimus. Both are located in the same region but have different roles to play in stability and movement. The gluteus maximus, for example, is the largest of the three and is used for extending as well as rotating the hip. In contrast, the smallest is the gluteus minimus, which is important in hip abduction and internal rotation. This muscle is used in daily activities such as getting out the side of a car.