The association between knee joint biomechanics and neuromuscular control and moderate knee osteoarthritis radiographic and pain severity

SummaryObjectiveThe objective of this study was to determine the association between biomechanical and neuromuscular factors of clinically diagnosed mild to moderate knee osteoarthritis (OA) with radiographic severity and pain severity separately.MethodThree-dimensional gait analysis and electromyography were performed on a group of 40 participants with clinically diagnosed mild to moderate medial knee OA. Associations between radiographic severity, defined using a visual analog radiographic score, and pain severity, defined with the pain subscale of the WOMAC osteoarthritis index, with knee joint kinematics and kinetics, electromyography patterns of periarticular knee muscles, BMI and gait speed were determined with correlation analyses. Multiple linear regression analyses of radiographic and pain severity were also explored.ResultsStatistically significant correlations between radiographic severity and the overall magnitude of the knee adduction moment during stance (r2=21.4%, P=0.003) and the magnitude of the knee flexion angle during the gait cycle (r2=11.4%, P=0.03) were found. Significant correlations between pain and gait speed (r2=28.2%, P<0.0001), the activation patterns of the lateral gastrocnemius (r2=16.6%, P=0.009) and the medial hamstring (r2=10.3%, P=0.04) during gait were found. The combination of the magnitude of the knee adduction moment during stance and BMI explained a significant portion of the variability in radiographic severity (R2=27.1%, P