Last month we discussed the very defined gluteus maximus, so this month we feel it is appropriate to talk about the smaller, but no less important gluteus medius.
The front part of the gluteus medius helps to bend the hip and rotate it inwardly. The back part helps to kick back the hip and rotate it outwardly.
Probably the most important job of the gluteus medius, when the front part and back parts work together, is stabilization of the hips during walking. When one side of the gluteus medius is weak it causes the opposite hip to fall when standing on one leg. Notice in the picture (A), the hips are level when standing on the right leg because the right gluteus medius is strong, but in (B) the right gluteus medius is weak, so the left hip falls. In physical therapy, this is referred to as a right Trendelenburg sign.