Seeking to find an agreeable handle size for hand tools to be used by either males or females when a custom-fit handle isn’t feasible, researchers recently suggested that the ideal grip handle diameter could be 33 mm. At this size, it is postulated that the least amount of hand muscle contraction is required by males and females to hold/carry a tool.
To determine an appropriate size, researchers used a validated, three dimensional hand model to estimate maximum muscle force that can be generated at varying grip sizes for males and females. The maximum grip force for females was 570 N at 32 mm grip diameter while the maximum male grip force was 710 N at 34 mm grip diameter.
The least amount of hand muscle activity required to hold a handle likely occurs at the grip size that is associated with maximum force. Based on this theoretical model, the authors suggest that a 33 mm handle diameter would be ideal to reduce the risk of forearm/hand cumulative trauma disorders related to tool use.
Sancho-Bru JL, Giurintano DJ, Perez-Gonzalez A, Vergara M. “Optimum Tool Handle Diameter for a Cylinder Grip.” Journal of Hand Therapy. 16:337-342, 2003.
Editor’s note: Ideally, rather than find a single size of handle that would be acceptable for most members of a workforce, ergonomics would more accurately be employed to provide various sizing through selection or adjustability.
This article originally appeared in The Ergonomics Report™ on 2004-03-01.