I fully agree with the answer given above by Hamdy Elsaid....
The first step should be get a full knowledge of anatomy muscles, attachments and sizes etc. Also, it would be worth reading previous work on other joints and muscular systems etc. Human upper limb system for example has been fairly well examined for years (from DR Wilkie...), see references in,
Article: Isometric tension development in a human skeletal muscle in relation to its working range of movement: The length tension relation of biceps brachii muscle
H.M. Ismail · K.W. Ranatunga
Full-text · Article · Jan 1979 · Experimental Neurology references in,