Abstract
Background & Objective: There is an increasing demand for computer aided instruments in medicine to assist doctors and technicians. This paper presents a simulation of skeletal model of human upper extremity, which monitors position, orientation, trajectory, force and torque generated by upper limb movement.

Materials and Methods: An artificial upper limb model is prepared with servo motors and aluminium T- section which moves in 2D vertical XY plane and whose control is through PC through user friendly software. In first phase: Values of time,power and torque were estimated for each joint after making the robot-model move in flexion and extension with different weights. In second phase: same values were estimated after strapping subjects arm and making the robot-model move in flexion and extension.

Results: Values of Power and Time taken by joints to lift weight at different speeds showed that torque and power are higher for higher flexion angle as well as higher load value. Experimental values for flexion of wrist (p<0.05), elbow (p<0.01), shoulder (p<0.05) with subjects, showed that time taken by elbow was lesser than that taken by wrist and time taken by shoulder was still lesser than elbow for same amount of weight lifted. Results considering force sensor showed that motor torque rises when load is lifted against gravity.

Conclusion: This model could be used as a tool in neuromuscular disorders for enhancing the functionality of robot assisted upper limb therapy and data from model could help the therapist to know about actual resistance force at each joint and quality of exercise trajectory achieved by each subject.

Key words: Torque; Upper Extremity; Power; Robotics; Anthropomorphic Arm; Simulation