Robotic exoskeleton-guided wrist motion assessment in young and older adults

This paper describes motion assessment in young adults (YA) and older adults (OA) during the use of an upper limb rehabilitation robot (ULRR). An experimental protocol was proposed to collect kinematic and surface electromyographic (sEMG) data from 20 participants. The protocol included the use of the ULRR along with an interface to execute standardized wrist movements randomly (flexion, extension, radial deviation, and ulnar deviation) at fixed intervals. For the sEMG, representative features were computed, and for the kinematic data, compensatory movements, reaction times, range of movement, and smoothness of movement were estimated. The results showed significant differences in the calculated metrics between YA and OA. The OA group reported 15.5% more compensatory movements and an average of 37 ms increment compared with YA times. Finally, the velocity curves showed more frequency components in OA, which, along with the estimation of the Spectral Arc Length, indicated a smoother movement in the YA group. These outputs can be used to create personalized therapies or to develop a methodology for assessing robotic rehabilitation.