Rules for Muscle Function and Shoulder Complex Movements, Study notes of Physical Education and Motor Learning

Download Rules for Muscle Function and Shoulder Complex Movements and more Study notes Physical Education and Motor Learning in PDF only on Docsity! Rules to Remember 1. Muscles only pull 2. Muscles pull toward their center from all attachments sites 3. Therefore, any bone can move (reverse action)  One bone usually more fixed by opposing forces/torques 4. Whether a bone moves or not depends on whether the opposing forces/torques are larger than the force/torque produced by the muscle 5. For linear motion, force must be produced by muscle 6. For rotation (angular motion) to occur at a joint, muscle must produce torque (have a moment arm) across that joint 7. Muscle must cross the joint  –Anterior to joint – flexion  –Posterior to joint – extension  –Medial to joint – adduction  –Lateral to joint – abduction  –Rotation? These are general rules only. The real key to knowing whether a muscle will cause a rotation is the location of the line of pull of the muscle and its moment arm relative to the joint axis (ML, AP, SI). Shoulder Complex Movements •Shoulder Girdle –Elevation & depression (L/FP) –Protraction & retraction (L/FP, A/TP) –Upward & downward rotation (A/FP) –Upward & downward tilt (A/SP) •Shoulder (glenohumeral) –SP  flexion, extension, hyperextension –FP  abduction, adduction –TP  medial rotation, lateral rotation, horizontal adduction, horizontal abduction Linear motion of the scapula or humerus relative to each other at this joint can occur in all planes.