Lesson
Muscles - continued
Muscle Roles
-Agonists (prime movers)CAUSE MOVEMENT (eg. brachialis, biceps b. in elbow flexion)
-Assistant Agonist (eg. brachioradialis, ECRL, pronator teres in elbow flexion)
-Synergists PREVENT UNWANTED MOVEMENT for more prime-mover efficiency
ALSO act as FIXATORS/STABILIZERS against a FORCE OR
(eg. quadriceps ie rectus femoris in hip flexion; pronator teresin elbow flexion)
-Antagonists RELAX TO PERMIT PRIMARY MOVEMENT, CONTRACT TO ACT AS BRAKE AT
COMPLETION OF MOVEMENT, esp. FAST, FORCEFUL MOTION (eg. triceps in elbow flexion)
-Stabilizers hold body parts immobile while others moves (eg. rhomboids stabilize scapula in flexion)
-Neutralizers prevents unwanted action of a muscle (eg. in elbow flexion pronator teres helps to prevent unwanted elbow supination effect of biceps brachii)