Forces applied to large hand wheels

This is a report of a study conducted to establish the population isometric strength capabilities of subjects generating force using a hand wheel. Wheel force strength of 125 males and 125 females was measured using two different handgrip configurations: grasping the rim of the wheel and grasping the spoke. In addition, two separate procedures for generating and measuring strength were used: a 3 s average during a 6 s trial, and a ramp to maximum exertion level and then relax. The task simulated setting a handbrake on a typical railroad box car. Results indicated that grip characteristics and grip strength play an important role in isometric wheel force strength capabilities. The average tangential forces ranged from 393 to 614 N for males, and from 235 to 348 N for females, depending upon the grip configuration and the method used to measure strength. Standard whole-body strength measures for the legs, arms, torso and grip were also measured and demonstrated to be effective in predicting the wheel force strength capabilities of the subjects.