Adaptations of Bone and Bone Vasculature to Muscular Stretch Training

The magnitude of bone formation and remodeling is linked to both the magnitude of strain placed on the bone and the perfusion of bone. We have previously reported an increase in bone perfusion and bone density that occurs in the femur of old rats with moderate aerobic exercise training. The purpose of this study was to determine the acute and chronic effects of static muscle stretching on bone blood flow and to determine whether chronic stretching affects bone remodeling. Old male Fischer 344 rats were randomized to either a naive or stretch-trained group. Static stretching of ankle flexor muscles was achieved by placement of a dorsflexion splint on the left ankle for 30 min/day, 5d/wk for 4wks. The right hindlimb served as a contralateral control (unstretched) limb. Bone blood flow was assessed during and after an acute bout of stretching in naive rats, and at rest and during exercise in stretch-trained rats. Following 4 weeks of daily muscle stretching, micro-CT analysis was used to determine the volume...