Skeletal robustness and bone strength as measured by anthropometry and ultrasonography as a function of physical activity in young adults

During the last 10 years, skeletal robustness in children has generally decreased. The reasons for this phenomenon, as well as its outcomes, are undetermined so far.The present study explores the association between anthropometric skeletal measurements, bone quality measurements, and physical activity in young adults.118 German young men (N = 68; 19-25 years old) and women (N = 50; 19-24 years old) were investigated by anthropometric methods (i.e., height, weight, shoulder, elbow breadth, and pelvic breadth) and quantitative ultrasound measurement (QUS). Strength and stability of Os calcis have been determined by speed of sound (in m/s) and broadband ultrasound attenuation (in dB/Mhz); individual physical activity was analyzed by a pedometer and by questionnaire.The results show a correlation between sports hours per week and bone quality index in males. But no correlation exists between anthropometric data and QUSs for either sexes, as well as no correlation between total steps per day and internal bone quality or external bone dimensions.These results are discussed in the context of generally decreasing physical activity, the outcomes of prevention programs as well as evolutionary adaptation of human phenotypic plasticity in a changing environment.