A Constant Force Resistive Exercise Unit

In space, muscles atrophy and bones weaken due to long-term disuse in response to the lack of a gravity resistance vector against which to eccentrically and concentrically do work. To counteract the negative effects of microgravity on muscles and bones, research suggests that astronauts perform muscle-strengthening resistive exercises while in space. Since the lack of gravity renders weight-bearing exercise and traditional weight machines useless, Valeo, Inc. has designed a gravity-independent constant force resistive exercise unit (CFREU) based on uniquely designed constant torque spring force packs. The CFREU has the ability to allow both eccentric and concentric muscle contractions during exercise while providing a constant force over the entire range of motion of an exercise. The CFREU additionally allows a variety of exercises to be performed, is safe, easy to operate during exercise, requires no power, and has a potential to provide an increased eccentric to concentric muscle loading ratio. The CFREU design essentially resembles a traditional isokinetic machine (with the replacement of the weight stacks by the force packs), thereby providing crewmembers with the familiarity and comfort of a typical weight-lifting routine.