Muscle Actions Flashcards
Coracobrachialis
Flexion and adduction of shoulder joint
Levator Scapulae
origin fixed: Elevates scapula
insertion fixed: Lat flexes cervical vertebrae and rotates bilaterally: may assist in extension
Latissimus Dorsi
extension, adduction, medial rotations of shoulder
Lower Trapezius
Scapular adduction, depression, + upward rotation
Middle Trapezius
Scapular Adduction
Upper Trapezius
Elevation of scapula + shoulder, capital ext, rotation of head to opposite side
Pectoralis Minor
Scapular Protraction, elevation of ribs in forced inspiration w/ scapula fixed by elevator scapula
Pectoralis Major
Whole: Adducts and medially rotates humerus, elevation of sternum in forced inspiration
Pectoralis Major (Clavicle)
Horizontal shoulder adduction, flexion and medial rotation
Pectoralis Major (Stern)
horizontal shoulder adduction, shoulder extension
Teres Major
Medially rotates, adducts and extends the shoulder joint
Subscapularis
Medially rotates the shoulder joint, + stabilizes the head of the humerus in the glenoid cavity during movements of the joint
Supraspinatus
Abducts the shoulder joint and stabilizes the head of the humerus in the glenoid cavity
Infraspinatus
Stabilize and externally rotate
Teres Minor
Laterally rotates the shoulder joint and stabilizes the head of the humerus in the glenoid cavity
Rhomboid Major
Scapular retraction
Rhomboid Minor
Scapular retraction and elevation
Serratus Anterior
Scapular abduction, holds scapula against thoracic wall, works w/ trap to rotate scapula upward
Deltoid
Abduction of shoulder
Middle Deltoid
Abduction of the shoulder joint, performed chiefly by the middle fibers w/ stabilization by the ant. and post. fibers
Triceps
Shoulder(long head) and elbow extension
Biceps
Supinates forearm when elbow is flexed
Scalenes
Cx flexion, lateral flexion same side, aides inspiration
Transverse Abdominus
Supports abdominal wall, aides forced expiration and raising intra abdominal pressure
Sternocleidomastoid
(unilateral) Lateral flex head to same side, rotates head to opposite side; bilaterally extends head