Postural analysis and workspace design using an analytically derived inverse kinematics model

A kinematics model of the upper limb was developed using three degrees of freedom on the shoulder and one on the elbow. Whilst the direct kinematics equation computes the position of the hand, the inverse kinematics equation provides the upper limb's joint angles related to a given posture. Only after defining a discomfort cost function that accounts for the joint's displacement from the neutral position, the inverse kinematics equation for this model proved analytically solvable. Such solution was used in conjunction with observational postural assessment methods in order to improve the subjective estimation of the joint angles. Besides that, it was shown the utility of the direct kinematics equation in the rearrangement of the elements of the workplace.