Effects of ulnar deviation of the wrist combined with flexion/extension on the maximum voluntary contraction of grip

Abstract

Work-related musculoskeletal disorders (WMSDs) is related with the frequency of exertion for repetitive tasks requiring heavy load. Different researchers have reported that a poor posture is very much responsible for WMSD if combined with increased load and/or frequency. In the assembly tasks in different industries involve the gripping very commonly. Therefore in the present study it was tried to find the effect of a wrist posture on grip strength. For design of experiment, subjects, flexion/extension and ulnar deviation of the wrist were taken as independent variables and the dependent variable was maximum voluntary contraction (MVC) of grip. The results showed that the effect of flexion/extension angle, ulnar angle and the subject on MVC grip were highly significant (i.e., p<0.001, 0.001 and 0.002 respectively). The two-way interaction effect of flexion/extension angle of the wrist and the subject on MVC grip was also found significant at p<0.001. The other interaction effects were not found significant. MVC grip was found maximum at the neutral wrist posture.