Relationship between lower limb neuromuscular performance and bone strength in postmenopausal women with mild knee osteoarthritis.

OBJECTIVES To investigate whether neuromuscular performance predicts lower limb bone strength in different lower limb sites in postmenopausal women with mild knee osteoarthritis (OA). METHODS Neuromuscular performance of 139 volunteer women aged 50-68 with mild knee OA was measured using maximal counter movement jump test, isometric knee flexion and extension force and figure-of-eight-running test. Femoral neck section modulus (Z, mm(3)) was determined by data obtained from dual-energy X-ray absorptiometry. Data obtained using peripheral quantitative computed tomography was used to asses distal tibia compressive (BSId, g(2)/cm(4)) and tibial mid-shaft bending (SSImax(mid), mm(3)) strength indices. RESULTS After adjustment for height, weight and age, counter movement jump peak power production was the strongest independent predictor for Z (β=0.44; p<0.001) and for BSId (β=0.32; p=0.003). This was also true in concentric net impulse for Z (β=0.37; p=0.001) and for BSId (β=0.40; p<0.001). Additionally, knee extension force (β=0.30; p<0.001) and figure-of-eight-running test (β= -0.32; p<0.001) were among strongest independent predictors for BSId after adjustments. For SSImax(mid), concentric net impulse (β=0.33; p=0.002) remained as the strongest independent predictor after adjustments. CONCLUSIONS Neuromuscular performance in postmenopausal women with mild knee OA predicted lower limb bone strength in every measured skeletal site.