Effect of Hand Grip and Center of Mass Location on Muscle Activity While Manipulating a Surgical Table Segment

OCCUPATIONAL APPLICATIONSHand grip location relative to the center of mass of an object can impact the activity of trunk and upper limb muscles. Aligning the hand grip location with the center of mass in the anterior/posterior direction minimizes muscle activity. Whether a proximal or distal grip requires more effort appears to be muscle dependent. Our work illustrates how design features influencing hand grip and center of mass location, such as handles and hand-operated mechanisms, can impact the user. Reducing physical effort via design is important to improve usability and help mitigate the high incidence of musculoskeletal injury resulting from manual materials handling tasks.