The Effect of Forearm Position, Hand Dominance, and Gender on Hand Grip Strength in Healthy Young Adults

Objective The aim of this study was to examine hand grip strength measured in different forearm positions in healthy young individuals and to evaluate the effects of forearm position, hand dominance, and gender on grip strength. Methods A total of 141 healthy volunteer individuals aged between 18–30 years (78 females, 63 males) were included in this descriptive and comparative cross-sectional study. Hand grip strength measurements were performed using the J-Tech Commander Echo Wireless digital hand dynamometer in accordance with the standard measurement protocol recommended by the American Society of Hand Therapists (ASHT). Measurements were taken in three different forearm positions—supination, neutral, and pronation—in both the dominant and non-dominant hands. Three repeated measurements were obtained for each position and the maximum value was used in the analyses. Descriptive statistics, paired samples t-test, independent samples t-test, and repeated measures analysis of variance were used in the statistical analyses. Results Grip strength values measured in the supination position were found to be the highest in both sexes, followed by the neutral position, while the lowest values were obtained in the pronation position. Grip strength values measured in the dominant hand were significantly higher than those in the non-dominant hand in all positions (p<0.001). In addition, the grip strength values of male participants were significantly higher than those of female participants in all positions (p<0.001). Repeated measures analysis of variance showed significant main effects of forearm position (F=368.85; p<0.001; η²p=0.515), hand dominance (F=432.47; p<0.001; η²p=0.384), and gender (F=184.61; p<0.001; η²p=0.210) on grip strength. Conclusion Forearm position is an important determinant of hand grip strength. Grip strength values are highest in the supination position and lowest in the pronation position. In addition, the dominant hand advantage and gender differences significantly influence grip strength. These findings emphasize the importance of standardizing forearm position in grip strength measurements and provide position-specific reference values for healthy young individuals.