PHTY101 Lecture Notes - Lecture 4: Serratus Anterior Muscle, Rotator Cuff, Upper Extremity Of Humerus
Document Summary
Teres minor and infraspinatus external rotation: the prevent the superior glide of the humeral head. Deltoid sometimes pulls the humerus upwards during abduction (causing it to hit the acromion) Teres minor, lower fibres of infraspinatus and the lower half of subscapularis provide a medial, downward pull to counteract this. Upper traps: mover (lateral rotation), and synergist (cancels the depression of lower traps) Middle traps: synergist (cancel protraction of the serratus anterior) Hence the net movement is lateral rotation. Lower traps: mover (lateral rotation), and synergist (cancel elevation of upper traps) Serratus anterior: mover (lateral rotation) and synergist (cancel retraction of middle traps) 2. 4 describe and state the functional significance of scapulohumeral rhythm. Describe the relationship of scapular and humeral movements during full abduction from the anatomical position: this is the repeatable coordination of movement between the humerus and the scapula. It is used to bring normal and most efficient shoulder motion.
