My question is: 1.In this lab, internal torque was derived from muscle force alone. Are there any other internal structures that could generate a torque at the shoulder (i.e. not muscle)? And if so, how? 2.In this lab, we assumed that the moment arm of the muscle did not change between the 90 and 45 conditions. Can you think of any factors which might dictate, or change, the moment arms of muscles?

3.Knowing what you do about how limb position can impact moment arms (particularly external), can you provide an example of how someone might unknowingly use this idea to "cheat" during an exercise?