Footedness related differences in femoral bone mineral density in elderly women with osteoporosis

Purpose: The presumed link between lateralized habitual motor activity and bilateral skeletal asymmetry, as result of bone functional adaptation, is the basis for inferences about bone mineral distribution; consequently, bone loss and osteoporosis. As there is no research connecting directly footedness with osteoporosis, the present study was designed to investigate their relation, in elderly women with osteoporosis. Methods: A sample of 420 white, Caucasian race women, older than 65 years, with previous diagnosis of osteoporosis, was recruited for the study. Finally, 164 women met the inclusion criteria and participated. The femoral neck and total hip bone mineral density (BMD) differences between right and left hips of 105 right-footed and 59 non-right-footed women, and the between footedness groups differences of the above right-left BMD differences, were measured with Dual-energy X-ray Absorptiometry (DXA). Results: In right-footers, total hip right-left BMD differences were statistically significant, favoring left femur [t(104) = -2.79, p < .01, two tailed]. In non-right-footers, femoral neck right-left BMD differences were statistically significant, favoring right femur [t(58) =2.025, p < .05, two tailed]. Femoral neck and total hip right-left BMD differences of right- versus non-right-footed women were statistically insignificant. Conclusion: The dominance of the right lower limb had an asymmetric effect on left total hip BMD, while non-right-footedness favored right femoral neck BMD. The findings highlighted the influence of load bearing effects of the body weight and muscle contractions on femoral BMD. We noted a possible association between footedness and BMD, as a result of bone functional adaptation.