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.
Vertebrates move by the actions of muscles on bones. Tendons attach many skeletal muscles across joints, allowing muscle contraction to move the bones across the joint. Muscles generally work in pairs to produce movement: when one muscle flexes (or contracts) the other relaxes, a process known as antagonism.