Optimizing handle size based on normalized hand size in a maximum vertical torque task.
Ergonomics in the Digital Age: Proceedings of the XVth Triennial Congress of the International Ergonomics Association, and The 7th Joint Conference of the Ergonomics Society of Korea/Japan Ergonomics Society. Seoul, Korea: Ergonomics Society of Korea, 2003 Aug; :1-4
An experiment was performed to evaluate the effect of handle size (from 25 to 50mm diameter) on handle comfort, finger force capability and torque performance, and to predict the optimal handle size based on a 'Normalized Hand Size (NHS)' in a maximum vertical torque task. Subjective comfort ratings were also recorded for each handle on a 7-point scale. Analysis of subjective ratings showed that the 45mm handle was rated as the most comfortable size followed by the 50mm handle. Most subjects rated the 25mm handle as "uncomfortable". The analyses of maximum torque showed that the 45 and 50mm handles produced 1.78 to approximately 1.8 times of the torque which could be achieved with the 25mm handle, whereas the finger force capabilities of these large handles were only 72 to approximately 78% of the smallest handle. The ratio of handle circumference to user's hand length, the NHS, was calculated and related to all dependent measures. Results indicate that an NHS of 87% and 78% of hand length maximized comfort and torque, respectively. From these ratios, the optimal handle size can be recommended based on the users' hand size in a vertical torque task.
Musculoskeletal-system; Ergonomics; Motion-studies; Posture; Musculoskeletal-system-disorders
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Ergonomics in the Digital Age: Proceedings of the XVth Triennial Congress of the International Ergonomics Association, and The 7th Joint Conference of the Ergonomics Society of Korea/Japan Ergonomics Society