Five Additional Terms

Isotonic Contraction Contraction in which the muscle shortens – Examples include: Bending the knee Rotating the arm Smiling

Isometric Contraction Contraction in which muscle length does not change – Example: Pushing against an immovable object (wall) Trying to lift a building

Synergist Help prime movers by producing the same movement or by reducing undesirable movements. – Example: Moving the bones in your hand.

Fixator Specialized synergists that are responsible for stabilization of a joint/muscle – Example: Muscles that maintain posture in spinal column

Tone State of constant, partial contraction of a muscle – Keeps muscle firm, healthy, and ready for use!!