plural snack bars. snack bar. noun. plural snack bars. Learner's definition of SNACK BAR. [count] : a public place where small meals and snacks are served usually at a counter. There's a snack bar at the pool where we can get nachos.
All muscles exert their force by pulling between at least two points of attachment. The movement that results from contraction is called the action of the muscle. Typically, one attachment remains stationary and is called the origin and the other attachment moves and is called the insertion. Almost all muscles cross at least one joint (moveable connection between two bones) and cause an action across that joint.
Agonist muscles cause a movement to occur through their own contraction. For example, the triceps brachii contracts during the up phase of a push-up (elbow extension). During the down phase of a push-up, the same triceps brachii actively controls elbow flexion while relaxing.ntagonist muscles oppose a specific movement. This controls a motion, slows it down, and returns a limb to its initial position. Antagonism is not an intrinsic property; it is a role that a muscle plays depending on the motion. If a motion is reversed, agonist and antagonist muscles switch roles.