Maximum acceptable manual arm forces for above-shoulder work

Developed by: Drs. David Rempel & Jim Potvin

Description: A tool that allows users to estimate safe maximum hand forces for a given hand location, force direction, and duty cycle. This tool works by multiplying the maximum hand force for a 25th percentile adult female in an ideal scenario, then reducing that force based on the arm position relative to the shoulder and the work-to-rest ratio for a given task. Use equations 1-4, 7, and 8 to compute the maximum hand force; the resource provides an example calculation.

Keywords: hand, force, max, limit, safe, push, pull, grab, grasp, female, glenohumeral joint, impingement