Correlation between Q angle and hip abductor muscle strength in patients with knee osteoarthritis

Abstract

The Q angle has a major impact on the lower limb’s static alignment in the frontal plane; also, the lever-arm distance between the hip and knee joint centers also changes the hip abductor muscles’ ability to produce torque. An association between Q angle and hip muscle strength has been investigated in different population. However, the relationship between Q angle and hip abductor muscle strength in early knee osteoarthritis has not been investigated. Therefore, the objective of the study was to investigate the correlation between Q angle and hip abductor muscle strength in patients with initial stage of knee osteoarthritis (OA). This is a correlation study. Fifty-four involved OA knee among 32 patients (26 female and 6 male), with mean age of 49.38 ± 5.68 years, were included in the study. The Q angle was measured by universal goniometer, and the hip abductor muscle strength was measured by a hydraulic handheld dynamometer. Spearman’s correlation coefficient test showed that Q angle is significantly (weak negative) correlated (r =  − 0.31; p < 0.05) with hip abductor muscle strength, in patients with knee osteoarthritis. There is a correlation between Q angle and hip abductor muscle strength in patients with knee OA. So, with the decrease in hip abductor, muscle strength may lead to increase in Q angle, which may be a factor responsible for early-stage degenerative changes in knee OA.