Final answer:
The non-linear relationship between muscular movements and joint movements is influenced by factors such as the change in pivot point and the dimensions of the system.
Step-by-step explanation:
There are several factors responsible for the non-linear relationship between muscular movements (linear actions) and joint movements (angular actions). One factor is the change in the pivot point of the joints as they are flexed, which affects the lever arms and the mechanical advantage of the system. This means that the force exerted by the muscles to produce a certain joint movement may vary depending on the position of the joint. Additionally, the dimensions of the system, such as the length of bones and the arrangement of muscles, also play a role in the non-linear relationship between muscular and joint movements.