Handle designs affect the biomechanics of arm and wrist motion. Carpal tunnel syndrome and some related hand and elbow disabilities seem to be relieved by adjustments in the shape or length of handles. for many tools, bending the handle reduces the bending of the wrist. with some handle designs, forces are transferred from the wrist and elbow to more powerful shoulder and back muscles. Bent handle for such tools as pliers, compression cutting tools, hammer, and lopping shears seem to reduce repeated trauma disorders and enhance use.