Effects of exoskeleton use on movement kinematics during performance of common work tasks: A case study

Background: An exoskeleton may assist performance of basic work-related tasks. Its application should not alter user kinematics, which compromise user safety. Objective: This case study was used to assess whether people wearing a lower-body K-SRD^™ exoskeleton could complete common work tasks without altering kinematics that may increase injury risk. Methods: Three males performed three tasks: kneeling and standing (kneel), lifting and lowering a weighted box floorto-waist (lift), and stair-climbing with a weighted box (climb), all repeated with and without exoskeleton use (EXO, NONE). Results: Kinematics with EXO often mimicked NONE. Hip and knee flexion with EXO often exceeded NONE without increasing heart rate for kneel. During lift with EXO, participants avoided greater lateral trunk flexion associated with injuries and used the preferred semi-squat technique. Participants produced more foot clearance with EXO than NONE during climb. Other outcomes of heart rate, perceived exertion, fatigue, and usability were mixed. Conclusions: EXO augmentation does not need to alter movement kinematics during performances of kneel, lift, and climb tasks. EXO kinematic alterations did not appear to compromise user safety in terms of lateral trunk bending. It may encourage good technique, such as greater foot clearance to avoid tripping, for some tasks, and changes in lifting strategies to avoid extreme flexion and protect passive tissues.