Skeletal_muscles are named using these criteria: the direction of the muscle fibers, the relative size of the muscle, the location of the muscle, the number of origins, the location of the origin and insertion, the shape of the muscle and the specific action that the muscle performs.

There are various types of skeletal muscle actions, including prime_movers (agonists), antagonists, synergists, and fixators.

NOTE:

Humans have a single trapezius muscle and a single deltoid_muscle, but cats have three of each. They are the clavotrapezius, acromiotrapezius, spinotrapezius, clavodeltoid, acromiodeltoid, and spinodeltoid.