Systems and methods are disclosed for generating a 3D avatar or instructions for movement of robotic limbs using a biomechanical analysis of observed actions with a focus on representing actions through computer-generated 3D avatars or instructions for movement of robotic limbs. Physical quantities of biomechanical actions can be measured from the observations, and the system can analyze these values, compare them to target or optimal values, and use the observations and known biomechanical capabilities to generate 3D avatars or instructions for movement of robotic limbs.