Structure and function of the hip abductors in hip osteoarthritis (OA)

World-first techniques have been developed in our laboratory for the examination of the hip abductors (gluteus medius (Gmed) and gluteus minimus (Gmin)) using intramuscular electromyography (EMG). These muscles are well known to be the key hip stabilizers during gait but we have shown them to be composed of multiple segments with unique functional characteristics.

Hip OA is frequently characterized by atrophy of these muscles and this results in significant functional deficits that are not improved by current rehabilitation programs. An improved understanding of the function of these unique muscle segments in hip OA patients will assist in developing more effective rehabilitation programs. Our work has seen the development of close links with allied health staff at Bendigo Health for the recruitment of participants. Our study has confirmed atrophy and increased levels of fatty infiltration in these muscles compared to a matched control group using magnetic resonance imaging (MRI). The EMG data on individual segments is currently being analyzed and will provide world-first data in an OA population. A second study looking at the function of these muscle segments before and after hip replacement surgery is now underway.