Int. J. Hum. Comput. Stud. | 2019
Development of an EMG-based exergaming system for isometric muscle training and its effectiveness to enhance motivation, performance and muscle strength
Abstract
Abstract Isometric exercises can be used for general strength conditioning or rehabilitation. To maximize their benefits without excess muscle fatigue, such exercises must be performed under medical prescription, which also needs to specify their intensity and duration. However, at home or at a clinic they are rarely real-time monitored or evaluated, which may delay or prevent goal achievement, with negative influence on participants’ motivation. Therefore, in this paper, it is introduced the development and clinical evaluation of an exergaming platform based on ElectroMyoGraphy (EMG) for the real-time monitoring and performance assessment of personalized isometric exercises. The system enables medical personnel to create personalized exergame sessions that oversee in real time the behavior of the main character in a game, based on the muscle force of the user, estimated from an EMG signal. In addition, it evaluates exercise performance, in terms of muscle contraction duration and relative effort during work and rest intervals. A data storage capability enables users to upload results in a cloud database, which can be accessed remotely by healthcare providers through an application. The system operates firstly by obtaining an EMG-force model for isometric contractions of the flexor digitorum superficialis muscle, which was then integrated in the exergaming platform. Then, a 4-week randomized controlled clinical trial was conducted with tailored isometric handgrip exercises using the proposed system versus conventional handgrip exercises to assess motivation and grip strength in patients with distal radius fracture. Exercise performance and subjective workload ratings were additionally evaluated. Results notably show that handgrip exercises with the proposed system yield an improvement in grip strength of 40.2% over conventional handgrip exercises, while experiencing higher motivation levels, contrasting with lower frustration and mental demand levels. However, continued research is ongoing to generalize the findings of the clinical trial to a larger patient population.