Maximum handgrip force in relation to upper limb posture--a meta-analysis.

Abstract

It is essential to establish normative values of handgrip force in relation to factors influencing the force. This study developed a predictive equation that expresses the maximum force of the handgrip in relation to upper limb posture and gender. To create the equation, data from published studies on experimental results of maximum handgrip force in different upper limb postures were used. Selected were only those studies that describe upper limb posture during experiments clearly enough so that it could be transferred according to the Seven Degrees of Freedom Model, which unambiguously defines upper limb posture with values of seven angles. A predictive equation for male maximum handgrip force in relation to angles of wrist flexion/extension, wrist adduction/abduction, forearm pronation/supination, elbow flexion, shoulder flexion/extension, shoulder horizontal adduction/abduction, and arm medial/lateral rotation along the long axis was developed. Also developed was a mathematical formula that expresses maximum handgrip force for men in relation to maximum handgrip force for women. The equation is general and can be used for calculating norm values. It can also be applied to a specific population by performing an experimental study for one upper limb posture and assessing maximum force on the basis of the predictive equation for others.