Evaluation of a dual-scales method to measure weight-bearing through the legs, and effects of weight-bearing inequalities on hip bone mineral density and leg lean tissue mass.

OBJECTIVE To investigate: the accuracy of measuring relative left/right weight-bearing using two identically calibrated weighing scales; the short-term weight-bearing tendencies in a general population of 9 participants and long-term in 42 females; the effect weight-bearing inequalities on hip bone mineral density and leg lean tissue mass. METHOD Participants were measured standing astride two scales. Short-term volunteers were measured 10 times on one visit, with repositioning between measurements and the long-term group were measured on three visits at 6 month intervals. Baseline bilateral hip and total body Dual X-ray Absorptiometry scans were performed on the long-term group. RESULTS The short-term Coefficient of Variation is 5.41% and long-term 7.01%. No significant correlations were found between hip bone density differences and weight-bearing inequalities, although a weak correlation of r = 0.31 (p = 0.047) was found for differences in leg lean tissue mass. CONCLUSION Left/right weight-bearing measured using two scales is a consistent method for evaluating weight distribution through the legs. The short- and long-term weight-bearing tendencies showed a similar degree of variation. Weight-bearing inequalities were not associated with any significant left/right differences in bone mineral density at the hip, but were weakly associated with left-right differences in leg muscle mass.