Protein builds and repairs tissue so I would say it helps build muscles because it builds and helps repair them when they are torn from exercise.
Answer:
Total force is altered by the starting resting length. In either lengthening the muscle or shortening it, both methods changed the total force generated by the muscle. If the muscle is lengthened the passive force increases, and if the muscle is shortened the active force increases. With each force (a&p) the total force is changed depending on the amount of either A or P forces.
