A Model to Assess Fatigue at Joint-Level Using the Half-Joint Concept

In this paper we focus on the modeling and evaluation of performance factors as human fatigue at joint level. We introduce the concept of half-joint pair to calculate fatigue at joint level, that is, at muscle groups level. The fatigue model is designed to enable to a posture optimization algorithm to adapt the human posture so that when fatigue appears it can be reduced. An Inverse Kinematics solver gets values of joints fatigue and evaluates whether it is necessary to minimize fatigue values. We use an activation/deactivation pattern for each half-joint to set/unset a fatigue reduction constraint when fatigue value reaches an established threshold. We make a comparison between experiments performed using several male and female and simulations generated by our animation environment.