Structural Analysis of the Human Knee Kinematic Chain

Abstract

The human knee is one of the most important joints for the function of walking. Due to its constant use and the load it supports, injuries can occur, which makes it necessary to use equipment to assist at the movement. Being a complex joint, human knee natural movement is difficult to reproduce. The use of equipment that presents restrictions on natural motion can cause injuries and overload other human joints. Hence the need to study anatomy from a mechanical point of view. This paper presents the structural analysis of the human knee, through graph theory. The relation between human body components and mechanical elements is established and the kinematic chain that represents the human knee is defined. The results show the kinematic chain that represents the human knee. However, actuation redundancies can be observed since a mechanical joint represents an agonist muscle in contraction and antagonist muscle in expansion. Therefore is proposes an equivalent kinematic chain without actuation redundancies. Important considerations are made to apply later in the design of prostheses, orthoses, and exoskeleton, aiming at greater proximity of movements of the knee.