tokens: The upper limb is modeled as a kinematic chain consisting of : three degrees of freedom ( DoF ) for the shoulder spherical joint ( i.e. abduction - adduction , flexion - extension and internal - external rotation of the upper arm ) , one DoF for the revolute elbow joint ( i.e. forearm flexion - extension , indicated ) , three DoF for the wrist spherical common ( i.e. pronation - supination , ulnar - radial deviation and flexion - extension of the hand ) .