| The loss of bone density, decrease in muscle strength and balance, and increase in falls that occur with aging and extended musculoskeletal unloading will conspire to increase the incidence of bone fractures. Loss of postural stability manifests as changes in sway characteristics, which can be used to assess a person's risk for an injury causing fall. Daily treatment of low magnitude mechanical signals (LMMS), introduced as whole body vibration (WBV) has been shown to improve bone and muscle mass in both humans and animals. In this proposal, a novel method of predicting and reducing fall risk is explored. In the first series of experiments, aspects of safety and transmissibility of LMMS is examined, in order to better understand the degree to which low magnitude acceleration effectively transmits through the human body, and the feasibility of delivering these treatments to those with debilitating conditions such as spinal cord injury or cerebral-palsy. Translating this to the clinic, a long term study was performed which demonstrated the ability of LMMS to maintain muscular and postural health during extended bed-rest. In this study, it was found the LMMS had little effect on bone loss showed significant benefit in maintaining both muscle strength and postural control. Finally, a group of studies were performed in which postural control in the elderly population was examined, and a novel method of predicting fall risk was developed. In both the bed-rest and fall-risk studies, a short duration (10 minutes per day) of extremely low magnitude (0.3g), high frequency (30Hz) mechanical signal treatment is implemented as a non-drug, non-invasive countermeasure to musculoskeletal degeneration. The results of the experiments presented in this thesis demonstrate that mechanical signals, and LMMS is particular, may help maintain or even recover musculoskeletal health in those most at risk of the effects of osteoporosis. |
