The effect of upper-extremity posture on maximum grip strength

Abstract

The objective of this study was to determine and document the position of peak grip strength in different shoulder, elbow, and wrist posture combinations. Fifteen (15) male subjects performed maximal exertions with their dominant hands in nine wrist postures, three elbow postures, and two shoulder postures. Analysis of the data revealed that shoulder and elbow angles had significant effect upon the grip strength. Similarly, it was seen that grip strength at elbow at 135 degrees flexion was significantly different from those with elbow at 90 and 180 degrees. Further, the results revealed that peak grip strength occurred at a combined posture of shoulder abducted 0 degrees, elbow flexed 135 degrees, and the wrist in the neutral posture. Decrements of up to 42% in grip strength could be seen as elbow and wrist angles deviated. This means that use of handtools at deviated postures of shoulder, elbow, and wrist would decrease the percent of MVC at which a worker operated. Hence, the implementation of the finding of this study might be a reduction in the risk of injury, increase in productivity, and well-being of the workers.