Relationship between bone mineral density of the proximal femur and strength of hip muscles in postmenopausal women

The relationship between muscle strength and bone density is well known, bu t only a limited number of studies relating muscle strength to bone mineral density of a site-specific limb have been performed. The main purposes of this study were as follows: (1) to assess the relationship between the stre ngth of hip muscles and bone mineral density of the proximal femur in 100 p ostmenopausal women; (2) to compare strength values of three subgroups, whi ch were formed on the basis of the femoral neck Z-scores. By using an isoki netic dynamometer (Cybex 350), muscle strength tests were performed for hip muscles and bone mineral density measurements were obtained by dual energy x-ray absorptiometry. Statistical analysis demonstrated a moderately posit ive correlation between bone mineral density of the femoral neck and hip mu scle strength (with abductors: r = 0.267, P = 0.008; with adductors: r = 0. 276, P = 0.007). A moderate correlation was also found between bone mineral density of Ward's triangle and hip adductors (r = 0.327; P = 0.001). When muscle strength mean values of subgroups were compared with each other, the re was no statistically significant differences. These data may suggest tha t the isokinetic strength of hip muscles may not contribute to the bone min eral density of the proximal femur.