Variable Resistance Suit (VARS) for Enhancing Resistance Training

Abstract

Muscle disorders and induced muscle atrophy impose critical risks to the well-being of an individual, limiting normal activities of daily living. Several resistance training methods exist that have effectively reversed the progression of muscle atrophy. Weightlifting and hydrotherapy are the two widely practiced schemes for resistance training; however, there is the potential risk of excessive loads exerted on the muscles during weightlifting, and limited accessibility and cost are barriers to hydrotherapy. An alternative is using a resistance band. Some limitations include engaging multiple muscles/joints while only unidirectional resistance is feasible. To address these limitations, a VAriable Resistance Suit (VARS) is designed to provide speed-dependent, bi-directional, and variable resistance at a single joint. As a proof of concept, an elbow module of VARS is developed and validated experimentally. A pilot study shows the changes in flexor and extensor muscle activations in response to eight different levels of resistance modulated by VARS. The clinical implications of VARS remain as future work, but the functionalities implemented in the presented VARS prototype and preliminary results suggest that VARS could be a viable solution and complementary to existing tools and techniques utilized in resistance training.