GAIT COMPENSATIONS IN PATIENTS WITH OSTEOARTHRITIS OF THE HIP AND THEIR RELATIONSHIP TO PAIN AND PASSIVE HIP MOTION

This study related mechanisms of gait compensations to the level of pa in and to limitations in passive motion in patients with osteoarthriti s of the hip. Joint motion, moments, and intersegmental forces were ca lculated for 19 patients with unilateral osteoarthritis of the hip (12 men and seven women) and for a group of normal subjects (12 men and s even women) with a similar age distribution. The patients who had oste oarthritis walked with a decreased dynamic range of motion (17 +/- 4 d egrees) of the hip and with a hesitation or reversal in the direction of the sagittal plane motion as they extended the hip. The patients wi th a hesitation or reversal in motion had a greater loss in the range of motion of the hip during gait (p < 0.004) and a greater passive fle xion contracture (p < 0.022) than those with a smooth pattern of hip m otion. This alteration in the pattern of motion was interpreted as a m echanism to increase effective extension of the hip during stance thro ugh increased anterior pelvic tilt and lumbar lordosis. The patients w ho had osteoarthritis of the hip walked with significantly decreased e xternal extension, adduction, and internal and external rotation momen ts (p < 0.008). The decreased extension moment was significantly corre lated with an increased level of pain (R = 0.78; p < 0.001). This find ing suggests that decreasing muscle forces (hip flexors) may be one me chanism used to adapt to pain.