Implications: Successful completion of this proposed project will provide the necessary groundwork to move forward with a multicenter clinical trial on a large number of subjects with a variety of neuromuscular conditions. The measurement device will allow us to correlate change in BMD with the specific load history for each participant, thereby allowing us to determine whether physical interventions can lead to increased BMD in individuals with neuromuscular disabilities. Analysis of the data will help define a dose-dependent relationship between load, duration and changes in BMD, thereby guiding providers and therapists in prescribing standing interventions.