Grip strength in different positions of elbow and shoulder

Abstract

This study investigated the effect of shoulder position on grip strength in 80 men and 80 women. A Jamar dynamometer was used to measure the grip strength in the four testing positions. The four hand strength tests consisted of three positions in which the elbow was maintained in full extension combined with varying degrees of shoulder flexion (ie, 0°, 90°, and 180°) and of one position in which the elbow was flexed at 90° with the shoulder in 0° of flexion. Only the dominant hand was tested. The highest mean grip strength measurement was recorded when the shoulder was positioned at 180° of flexion with elbow in full extension; whereas the position of 90° elbow flexion with shoulder in 0° of flexion had the lowest grip strength score. In addition, the grip strength measured with the elbow in extension, regardless of shoulder position (ie, 0°, 90°, and 180° of flexion), was significantly higher than when the elbow was flexed at 90° with the shoulder positioned at 0° of flexion. Finally, grip strength differed significantly for both sexes and for each age group. The grip values of the standardized 90° elbow flexed position were further analyzed to determine the average performances in the study population. For men, grip strength peaked within the 20 to 39 years age group and gradually declined thereafter. For women, the highest mean grip strength measurement was recorded in the 40- to 49-year-old age group and the deteriorated with age. The findings are valuable in the evaluation and rehabilitation training of hand injured patients.