Techniques for establishing a biomechanical model of a user performing motion are described. A plurality of sensor modules corresponding to a set of designated body parts (e.g., arms or legs) of the user generate sensing signals when the user performs a pose. Sensing data including accelerometers and/or gyroscopes data generated from the sensing signals is analyzed to detect a medio-lateral direction of each of the designated body parts to infer the pose from the captured motion of the user.