Kinesiology 2241A/B Lecture Notes - Lecture 12: Human Musculoskeletal System, Length Overall, Scapula

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 2241A/B
• Professor: Thomas Richard Jenkyn

Document Summary

Wedge = machine b/c changes direction of force. Lever = machine push one side then force on the other. Long rigid segment + point of rotation = fulcrum. Force applied to rigid segment = rotates around fulcrum (creates new force) Lever changes magnitude + direction of force applied to it. Musculoskeletal system - bones = rigid segments + fulcrum is the joints. Pulls along line of action along back of calcaneous (lever) Force applied - don"t want force but want ankle to rotate. Force = a vector (therefore = 4 characteristics) Direction of pull changes direction of the muscle (lg range of motion, muscle switches what they do) Draw +ve + -ve lines of action (tells you what the muscle has) Example: gastronemius loa will work w/ ankle (not always flexion) i. Amount of activation (from brain via motor nerve) Force determined by muscles - length compared to optimal length.