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

ABSTRACT

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 (ß=0.44; p<0.001) and for BSId (ß=0.32; p=0.003). This was also true in concentric net impulse for Z (ß=0.37; p=0.001) and for BSId (ß=0.40; p<0.001). Additionally, knee extension force (ß=0.30; p<0.001) and figure-of-eight-running test (ß= -0.32; p<0.001) were among strongest independent predictors for BSId after adjustments. For SSImax(mid), concentric net impulse (ß=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.