A muscle that assists an agonist by causing a like movement or by stabilizing a joint over which an agonist acts is a(n) a. antagonist, b. prime mover, c. synergist, d. agonist.

Video transcript

Hey, everyone. Let's take a look at this question together. The movement of the body involves the coordinated action of several muscles acting together the fibers of which of the falling muscles are stretched and relaxed. When the prime mover is active, is it answer choice? A agonists answer choice B, the fixators answer choice C synergist or answer choice D the antagonists let's work this problem out together to try to figure out which of the following answer choices is the correct answer. So in order to solve this question, we have to recall what we know about the different muscles that are involved in stretching and relaxation in relation to the prime mover. And we note that another term for the prime mover is called the agonist. Since the prime mover is the muscle that provides the primary force or the action. And the agon muscles when the prime mover is active are the muscles that contract. So we are looking for the muscles that are stretched and relaxed, which means that these are the muscles that are opposite of the muscles that contract. So they are the muscles that are opposite of the agonist. And we know that the muscles that are opposite of an agonist are the muscles that are the antagonist. Since the antagonistic muscles are those that oppose the action of the prime mover or the agon muscles. And the antagonistic muscles are the ones that are stretched and relaxed when that prime mover is active. Therefore, answer choice D antagonists is the correct answer. Since the agon muscles are the ones that contract when the prime mover is active. And the synergist are those muscles that assist the agon muscles. So answer choices A and C are incorrect and fixators answer choice B is incorrect since they don't involve any significant stretching or relaxation, giving us the correct answer, which is answer choice D I hope you found this video to be helpful. Thank you and goodbye.