There are three main gluteus muscles that traverse the outside of the hip – the gluteus maximus, gluteus medius and gluteus minimus.  The gluteus maximus is the largest and helps move the thigh back (extension) and rotate the thigh out (external rotation).  While gluteus maximus is the largest, it is gluteus medius that is the most important for normal hip function and walking.  The gluteus medius muscle is for the hip what the rotator cuff muscles are for the shoulder.  Most importantly, the gluteus medius keeps the pelvis level when walking and running, and it also functions in abduction (moving the thigh and leg directly out to the side).  When this muscle is weak or injured, pain and an abnormal gait can result.  The majority of pain in this area is related to tendonitis, which can be treated with rest, activity modification, anti-inflammatory medications (NSAIDs), physical therapy, and occasionally injections.  The tendon of the gluteus medius muscle can also be torn, which typically happens over time like a rotator cuff.  This also causes pain, an abnormal gait and very commonly causes weakness.  When the tendon is partially or completely torn, non-surgical options, including rest, activity modification, anti-inflammatory medications (NSAIDs), physical therapy, and occasionally injections, can help symptoms, but these cannot heal the tendon.  When non-surgical treatments fail to improve symptoms and strength, the tendon can be repaired surgically with good results.