i have a robotic arm .. i need to obtain the torque of the servo motor in the shoulder .. i succeeded to move the arm in motion analysis using ( constant speed motor , segments , Data points, ) but they all give me high torque .. around 37 kg.cm  which is for this arm is very high .,, so i want to try the servo motor approach...  when i use the servo motor  the arm dosen't move although the motion analysis calculate and no redundancies appear ... help me please ?!

i need the steps of how to use the servo motor properly ....