KINESIOL 1A03 Lecture Notes - Lecture 11: Levator Scapulae Muscle, Shoulder Girdle, Latissimus Dorsi Muscle

• School: McMaster University
• Department: Kinesiology
• Course: KINESIOL 1A03
• Professor: Krista Howarth

Document Summary

Origin attachment of a muscle"s tendon to the stationary bone (usu proximal) Insertion attachment of the muscle"s other tendon to the movable bone (usu distal) Belly (body) fleshy portion of the muscle btw the tendons. Lever- rigid structure that can move around a fixed point called a fulcrum. A lever is acted on at two different points by two different forces: the effort, which causes mvmt and the load or resistance, which opposes mvmt. Most skeletal muscles are arranged in opposing pairs at joints e. g. flexors-extensor, abductors-adductors. Prime mover or agonist (leader) contracts to cause an action while the other muscle. Antagonist stretches and yields to the effects of the prime mover. If primer mover and its antagonist contract at the same time with equal force, there will be no mvmt. Synergist muscles that prevent unwanted mvmts at intermediate joints or to otherwise aid the mvmt of the primer mover by contract and stabilizing the intermediate joints.