Pre-operative hip abductor muscle function in osteoarthritis, a comparison with healthy asymptomatic individuals

grantor: University of TorontoHip abductor muscle function was examined in 17 young healthy males (YN), nine older healthy individuals (ON) and 11 patients with hip osteoarthritis (HOA). Tensor Fascia Latae (TFL) and Gluteus Medius (Gmed) electromyography during isokinetic hip abduction and ambulation were recorded. The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index was used as a measure of clinical status. Isometric (ISO), concentric (CON) and eccentric (ECC) hip abductor muscle strength were decreased in HOA patients (p $<$ 0.005) when compared to ON individuals. Increased activity of TFL and decreased activity of Gmed were observed during the stance phase of gait in HOA patients. Gait velocities were decreased in HOA patients (p $<$ 0.03). Patients spent proportionately less time in single support and more time in double support during the stance phase of gait. Significant positive correlations between gait velocity and CON hip abductor strength (r = 0.56, p = 0.013) and between gait velocity and ECC hip abductor strength (r = 0.54, p = 0.016) were found. WOMAC signal measures 'pain' and 'difficulty' while walking significantly related to CON (r = $-$0.94, p = 0.0001, r = $-$0.66, p = 0.027) and ECC (r = $-$0.84, p = 0.0003, r = $-$0.60, p = 0.048) hip abductor strength. Although a relationship exists between pain and hip abductor muscle strength, and between gait velocity and hip abductor muscle strength, the relationship between pain and gait velocity requires further investigation.M.Sc