Question

a muscle that opposes, or reverses, a particular movement is a(n)
a) antagonist
b) synergist
c) agonist (prime mover)
d) fixator

Explanation:

• An antagonist muscle opposes or reverses a movement. For example, when the biceps (agonist) contracts to flex the elbow, the triceps (antagonist) relaxes. When the triceps contracts (antagonist action), it extends the elbow, reversing the flexing movement.
• A synergist helps the agonist muscle. An agonist (prime mover) is the main muscle causing a movement. A fixator stabilizes a bone or joint.

Answer:

A. antagonist