Grip Strength Normative Data For the Harpenden Dynamometer

Abstract

Grip strength measurement provides an objective index about the functional integrity of the upper extremities. The Harpenden(R) dynamometer is a new mechanical device used to assess grip strength; however, there is a dearth of information on its ability to reproduce results and a scarcity of norms to which patient data can be compared. The purposes of this study were to determine the reliability of the Harpenden dynamometer and to establish normative data for the dynamometer. In a pilot study, the authors recruited 120 college students (60 male and 60 female) and measured their right and left hand grip strength on two different occasions 1 week apart. No significant differences (p > 0.05) were found between the readings on day one and day two, and all Pearson product-moment correlation coefficients (calculated for the male and female data separately and combined) were greater than 0.90 (p < 0.001). During the main study, grip strength of both extremities was measured in 960 subjects (480 men and 480 women) ranging in age from 7 to 84 years. In both hands, grip strength increased with chronological age and peaked between 30-39 years in males and 20-29 years in females. The student t-test result revealed that grip strength in males was consistently higher (p < 0.01) than females for all ages except during the first decade of life. After 30, male grip strength is nearly double female grip strength. The paired t-test showed that right hand grip strength was significantly (p < 0.0001) greater than left hand grip strength at all ages. The one-way analysis of variance and Scheffé post hoc test for strength data in both extremities revealed that, in general, there were significant (p < 0.05) differences in grip strength with each corresponding decade. The authors have presented grip strength norms for both sexes at different ages and discussed the clinical relevance of their findings. J Orthop Sports Phys Ther 1991;14(4):155-160.