Establishing the torsional rigidity of a rotation module responsible for the flexion-extension motions of the elbow

Abstract

The paper presents and discusses a system devised for the mobilisation of the elbow including a pair of agonist-antagonist pneumatic muscles aimed mainly at ensuring the accuracy of the rotation angle. This system is of SISO type (single input - single output) with the variable Δp (the pressure by that one of the muscles is charged symmetrically in the detriment of the other) as its input value. Further discussed are the dependency of the equilibrium angle on Δp and the possibility of controlling the torsional rigidity by adjusting the sum of the feed pressures.