Evaluation of a treadmill with vibration isolation and stabilization (TVIS) for use on the International Space Station

A treadmill with vibration isolation and stabilization designed for the int ernational Space Station (ISS) was evaluated during Shuttle mission STS-81. Three crew members ran and walked on the device, which floats freely in ze ro gravity. For the majority of the more than 2 hours of locomotion studied , the treadmill showed peak to peak linear and angular displacements of les s than 2.5 cm and 2.5 degrees, respectively. Vibration transmitted to the v ehicle was within the microgravity allocation limits that are defined for t he ISS. Refinements to the treadmill and harness system are discussed. This approach to treadmill design offers the possibility of generating 1G-like loads on the lower extremities while preserving the microgravity environmen t of the ISS for structural safety and vibration free experimental conditio ns.