The effect of dynamic muscle stimulation on the musculo-skeletal remodeling

Elucidation of the interactive mechanism between musculoskeletal circulations and bone remodeling is crucial in developing new intervention to prevent bone loss under a microgravity environment. The overall hypothesis is that dynamic muscle stimulation can enhance fluid circulation in bone, regulate osteogenic adaptation, and inhibit bone loss in a functional disuse condition. Using a hindlimb suspension rat model, electro-induced dynamic muscle contraction was induced as replacement of the normal weight-bearing activity of the hindlimb. Dynamic muscle contraction loading at 20 Hz and 50 Hz demonstrated increase of BV/TV, Conn.D, and Tb.N at the metaphyseal regions, when comparing to the hindlimb suspension control. In addition, stimulation at 20 Hz and 50 Hz can also alleviate the reduction of the cross-sectional fiber area. These results demonstrated that dynamic electro-induced muscle contraction can indeed initiate an adaptive response to inhibit bone loss and reduce muscle atrophy under a functional disuse environment.