Abstract: The purpose of this study was to examine the relationship between hand size and grip strength at various handle positions using the Jamar handheld dynamometer in females. Eighty-eight female physical therapy students between the ages of 20 and 40 were recruited. Subjects were weighed and their height measured. Right hand size was determined by measuring from the distal tip of the third digit to the radiocarpal joint with a tape measure. Subjects were divided into two groups by hand size (<7.0 and ≥7.0 inches). The order of handle positions was randomly selected. Subjects were seated according to the American Society of Hand Therapists’ recommended testing position with shoulder adducted and neutrally rotated, elbow flexed to 90° and forearm and wrist in neutral. Subjects maximally squeezed the handle of the dynamometer with the right hand for 3 s. This process was repeated three times at each handle position. A repeated measures ANOVA was performed comparing the change in average grip strength between position 2, 3 and 4 for small and large hands. The mean age of the two groups were similar (25.96 vs. 25.89, p=0.95). Subjects with smaller hands were shorter (61.7 vs. 65.5 inches, p=0.0001) and produced lower grip strengths than those with large hands at all positions (p=0.0084). Height and hand size were strongly correlated (r=0.74, p=0.0001) as were height and weight (r=0.66, p=0.0001) and weight and hand size (r=59, p=0.0001). Height was the most strongly correlated with grip strength at all positions followed by hand size then weight. Age was shown not to be significantly correlated with grip strength in this study. These findings suggest that handle position 2 and 3 produce similar grip strength measurements even in women with smaller hands. Position 4 is significantly worse than positions 2 and 3.
Keywords: Grip, Jamar dynamometer, Grip strength, Hand size
