Grip forces of the fingertips.
OBJECTIVE
A model has been developed for the power grip on a cylindrical handle. The model gives estimates of the forces acting on the fingertips as functions of total grip force, diameter of the handle, and hand size.


METHODS
The data in the literature were used to estimate the parameters of the model. An experiment was conducted to verify that the distribution of the forces is independent of the force level.


BACKGROUND
In the authors' opinion, the outcomes of the various experiments described in the literature can be represented in a compact model without too much information loss.


METHODS
The forces acting on the fingertips of 10 subjects were measured with three different handle diameters and five grip force levels.


RESULTS
The force sharing turned out to be independent of the grip force and the diameter of the handle.


CONCLUSIONS
It is advantageous to shape the handle so that the local diameters at the fingers are proportional to the finger lengths.


CONCLUSIONS
Knowing the force distribution of the power grip is important in design of handles. Experimental data presented in a concise form is needed also in the development of biomechanical models.
Department of Physiology, Finnish Institute of Occupational Health, Musculoskeletal Research Unit, Topeliuksenkatu 41 a A, FIN-00250 Helsinki, Finland. jouni.freund@occuphealth.fi
Jouni
J
Freund
Risto
R
Toivonen
Esa-Pekka
EP
Takala
D001696:Biomechanical Phenomena; D005260:Female; D005385:Fingers / Q000502:physiology*; D018737:Hand Strength; D006801:Humans; D008297:Male