The effects of working height on a manual lifting task

Confusion exists in the manual lifting and handling literature between the effects of working height at the bottom and top of a lift. This study varied both heights and measured the maximum weight lifted for male and female subjects using a non-compact box. Both bottom and top height affected weight lifted. The actual weights lifted and the relationships between male and female performance were consistent with the literature. It was found that the maximum voluntary strength at the top of the lift was not a good prediction of performance, suggesting that skill as well as strength define performance limits for this task. The implications for performance models are discussed.