Solving direct (forward) and inverse kinematic problems of multi-joint systems. Optimization in the neural control of movements - minimal jerk, minimal energy, minimal torque change models. Geometric and material and neuro-mechanical muscle characteristics. Electromyography. Redundancy of the motor system. Variances in movement execution, controlled and uncontrolled manifolds. Muscle- and joint synergies. Sensory-motor transformations, high dimensional biological coordinate systems. Dimension reduction methods, non-negative matrix factorization, principal component analysis, and their application in control of human-machine interfaces. Body-machine interface. Motor impairments and medical rehabilitation. Application of functional electrical neuro-muscular stimulation.