Biomechanical Consequences of the Hand's Action on Unstable Handle

The concept of muscular stabilization refers to imposing active muscular constraints on the joint degrees of freedom that are not used in a given motor task and the stabilization of unstable working objects. The human organism bears considerable cost due to the realization of this process, which in the case of muscular static force developed in relation to an unstable working object reaches approximately 24%. The aim of this article is twofold: (a) to determine the useful efficiency of the hand-working object system with an unstable handle in relation to the released muscular force and power dynamics and (b) to identify the relative contribution of the upper extremity muscles engaged in the realization of motor or stabilizing functions in the electromyography (EMG) sphere.