The impact of finger position on pinch strength

Introduction Pinch strength is a widely used measurement of hand function, but digit position on the pinch gauge has not been described in the literature. The aim of this study was to assess for differences in tip, lateral, and three-jaw-chuck pinch force when the digits are placed on the groove or bridge of a Bernadette and Linda pinch gauge. Methods Thirty-six healthy volunteers each pinched six times in random order: one for each type of pinch force with the digits placed in each position. Results There were no significant differences in pinch strength measurements based on digit position, except for three-jaw-chuck pinch which was slightly higher on the groove. Equivalence was found within one pound for tip and lateral pinch but not for three-jaw-chuck. Conclusion Variations in finger position may result in similar pinch strength measurements for tip and lateral pinch. Clinicians may reliably assess lateral and tip pinch using either position; however, standardized positioning is still recommended.