Measuring Muscle Activation with the HRX-1 Wrist Manipulation Robot

A portable robotic system, such as the HRX-1 robot designed for neuromechanics and rehabilitation research, enables motor assessment and training across diverse settings including clinics, laboratories, and home environments. This study presents the findings of wrist muscle activation measurements conducted using the HRX-1 robot in conjunction with surface electromyography (sEMG) electrodes on a cohort of fifteen healthy participants. Participants were seated and instructed to resist and maintain wrist flexion and extension against torques applied to their hand by the robot. Muscle activation data were recorded using two 32-channel highdensity surface EMG electrodes placed on the forearm to capture activity from the flexor and extensor muscle groups. The analysis focuses on identifying the number of active regions within the recorded muscle activations under each experimental condition. As expected, flexor muscles were most active during wrist flexion and extensor muscles were most active during wrist extension. There was also no statistically significant change in the number of muscle regions active when torque was increased in each configuration.