Understanding Muscle Roles & Agonist-Antagonist Pairs

Five vocabulary flashcards covering key terms related to muscle roles and agonist–antagonist relationships from the lecture notes.

Prime Movers (Agonists)

The primary muscles directly responsible for executing a movement; they initiate the action and shorten during contraction (e.g., quadriceps for knee extension).

Synergists

Muscles that assist the prime mover by adding extra force, guiding the movement, or stabilizing intermediate joints to ensure smooth action.

Fixators

Muscles that stabilize the origin point of the prime mover's attachment, allowing the prime mover to act more efficiently on the intended joint.

Agonist

The muscle or muscle group that contracts to cause a particular movement; the 'worker' in the team that initiates the movement and typically shortens (concentric contraction). Example: biceps during a bicep curl.

Antagonist

The muscle or muscle group that opposes the action of the agonist; it typically relaxes or lengthens to allow the movement (eccentric contraction or relaxation). Example: triceps during a bicep curl.