Development and Usability of a Prototype Upper Extremities Lever-Driven Exercise System

The purpose of this paper is to present the design, construction, and technical aspects of a prototype upper extremities lever-driven exercise system, called FIT-WHEEL (Functional and Intelligent Training system for WHEELchair users), as well as the preliminary experimental measurements conducted to test the device’s usability in healthy individuals. FIT-WHEEL was developed to provide a training modality that combines the known benefits of eccentric exercise and lever-propelled wheelchairs. Eleven healthy male participants performed, seven days apart, a moderate intensity concentric and eccentric exercise protocol on FIT-WHEEL consisting of 30 trials of both upper extremities at 30% of peak concentric and peak eccentric force, respectively. At the end of each exercise bout, participants completed a number of valid and reliable instruments examining attitudes, intention and enjoyment during concentric or eccentric exercise on the FIT-WHEEL system as well as the usability of the two exercise protocols on the novel lever-driven exercise system. Statistical analyses revealed high scores in all the examined parameters (attitudes, intention, enjoyment, and usability) in both eccentric and concentric exercise protocols, without any significant differences emerging between them. Moreover, total mechanical work during eccentric exercise was 18.3% higher compared to concentric exercise performed on the FIT-WHEEL training system (p = 0.001). The preliminary experimental results discussed serve as an initial step to implement lever-driven eccentric exercise in wheelchair dependent populations in the future and evaluate the potential long-term benefits and limitations.