Handle positions in a holding task as a function of task height.

Six handle positions in a two-handed container holding task were tested with the container at floor, waist and shoulder heights. Fifteen male and fifteen female manual materials handlers participated. Handle-position effects on forces exerted, heart rate and psychophysical indices were large compared with the effect produced by a 25% change in container weight. As in a previous study (at waist height only) and an industrial survey, handle positions providing both horizontal and vertical stability were better than symmetrical positions. Optimal angles of handle to container changed greatly with task height, giving almost horizontal angles at floor level and almost vertical angles at waist and shoulder level. Implications for the design of handle cutouts on containers are discussed