To Produce Smooth Movement at a Joint

Question

To produce smooth movement at a joint
A) the prime mover and antagonists must contract
B) the antagonist and synergists must contract
C) the prime mover and synergists must contract
D) both a and b above

Accepted Answer

Smooth movement at a joint is produced when the prime mover and the synergists contract together. The prime mover provides the main force for the movement while the synergists help to stabilize the joint and ensure the movement is smooth. The antagonists then relax to allow the movement to occur smoothly. Therefore, choice B is incorrect as the antagonists should not contract during smooth movement. Choice A is incorrect as the antagonists should only relax during smooth movement. Choice D is incorrect as only choices A and B are combined, which is not the correct combination for smooth movement.