The current increase in health awareness has led to greater attention to exercise. However, the growing number of competitors in various sports has caused a concomitant increase in the number of injuries during matches. After an injury, an immediate return to competition is difficult. A related problem is the shortage of athletic trainers. Strong teams such as professional, corporate, and university teams retain athletic trainers who can create unified plans spanning from injury to recovery, including subsequent recurrence prevention. However, only a fraction of teams can maintain such support staff, and so measures to accommodate the increase in the competitive population in various sports are beginning to fall increasingly behind. Competitive sports are supported by the continued influx of amateur athletes, and so when members quit due to injury or injury aggravation, it is undesirable both for the individual and for the sport as a whole. Thus, there is a need to develop rehabilitation devices that can provide an environment in which the user can safely be rehabilitated while determining his or her own state of recovery even if no athletic trainer is available. Conventional rehabilitation devices have emphasized recovery of cardiopulmonary function or the function of specific joints, with little to no development of devices aiming for an early return to competition. Against this background, the objective of this study is to design and develop a rehabilitation device that prevents reduced range of motion in joints and also prevents decreased muscle strength and . *1 正員,山形大学大学院理工学研究科(〒992-8510 山形県米沢市城南 4-3-16) *2 元 山形大学大学院理工学研究科 *3 山形大学大学院理工学研究科(現 技研(株) (〒175-0081 東京都板橋区新河岸 2-8-24) ) *4 山形大学大学院理工学研究科(現 会津オリンパス(株) (〒965-8520 福島県会津若松市門田町大字飯寺字村西 500) ) *5 山形大学大学院理工学研究科(現 アルパイン(株)