Low Cost Biofeedback System for Muscular Strength Analysis and Training

Muscular strength is a critical biological variable in order to perform any motor tasks associated with activities based on our daily life. Although advances in this area have been increased, it involves complex biomechanical and physiological mechanisms to be understand, which makes it still a challenge in his area. Diseases such as stroke (cerebrovascular accident - CVA) cause loss of muscle strength and affect severely the balance. This study aims to develop a low cost system for training and analysis of force in a biofeedback path. Both homemade hardware and software were implemented by consisting of an electromyography (EMG) system, a handgrip dynamometer and an inertial sensors based on accelerometer and gyroscope. EMG and muscular strength data were collected from a male volunteer of 44 years old. EMG data are compared to the medical literature. These preliminary tests showed that the system meets the hardware and software requirements for use in biofeedback according to the medical compliance for this type of device. Results from handgrip tests showed that the wrist angle is very important to determine correctly the muscular strength. The proposed system might be used to evaluate muscular strength in post-stroke patients.