noun
agonist
A muscle whose contraction produces a particular movement.
During an elbow curl, the biceps acts as an agonist.
Etymology
Greek agōnistēs named a contestant or combatant. In muscle terminology, the agonist is the active performer of a movement, contrasted with an antagonist whose action opposes it.
More examples
- The agonist contracts while an opposing muscle lengthens.
- Different movements recruit different muscles as agonists.
- The therapist identifies the main agonist for knee extension.
Forms
agonist · agonists
Similar words
- prime mover
- Specifies the muscle chiefly responsible for a movement.
- synergist
- Assists the main muscle rather than necessarily providing primary force.