Anatomy and Physiology of Human Movement 420:050 The Shoulder Girdle Anatomy and Physiology of Human Movement 420:050

Objectives Bones, bony landmarks and joints Muscles Movements

The Shoulder Girdle The scapula and clavicle Two joints Functions Dynamic stability Increased ROM

From Seeley RR, Stephens TD, Tate P; anatomy and physiology, ed 7, New York, 2006, McGraw-Hill

From Seeley RR, Stephens TD, Tate P; anatomy and physiology, ed 7, New York, 2006, McGraw-Hill

Joints Shoulder girdle (scapulothoracic) Scapula moves on the rib cage Joint motion occurs at sternoclavicular joint & to a lesser amount at the acromioclavicular joint

Joints Sternoclavicular (SC) Anteriorly with protraction (Multiaxial) arthrodial/gliding classification Movements Anteriorly with protraction Posteriorly with retraction Superiorly with elevation Inferiorly with depression

Joints Acromioclavicular (AC) Movements Often injured Arthrodial/gliding classification Movements Some gliding & rotational motion accompanying other shoulder girdle & shoulder joint motions Often injured

Objectives Bones, bony landmarks and joints Muscles Movements

Muscles Five muscles primarily involved in shoulder girdle movements All originate on axial skeleton & insert on scapula and/or clavicle Do not attach to humerus & do not cause shoulder joint actions Functions: Stability ROM of shoulder joint

Shoulder Girdle Muscles Five muscles primarily involved in shoulder girdle movements Trapezius - upper, middle, lower Rhomboid - deep Levator scapula Serratus anterior Pectoralis minor - deep

Trapezius

Levator Scapulae

Rhomboids

Serratus Anterior

Pectoralis Minor

Subclavius

Objectives Bones, bony landmarks and joints Muscles Movements

Movements Focus on specific bony landmarks inferior angle glenoid fossa acromion process Shoulder girdle movements = scapula movements

Movements Elevation Depression upward or superior movement, as in shrugging shoulders Depression downward or inferior movement, as in returning to normal position

Movements Abduction (protraction) Adduction (retraction) scapula moves laterally away from spinal column Adduction (retraction) scapula moves medially toward spinal column

Movements Upward rotation Downward rotation turning glenoid fossa upward & moving inferior angle superolaterally away from spinal column Downward rotation returning inferior angle inferomedially toward spinal column & glenoid fossa to normal position

Shoulder Girdle Movements Elevation Shoulder Girdle Movements Abduction Adduction Upward Rotation Downward Rotation Depression

Movements Anterior tilt (upward tilt) Posterior tilt (downward tilt) Rotational movement of scapula about frontal axis Occurs during glenohumeral hyperextension Posterior tilt (downward tilt) Occurs during glenohumeral hyperflexion

Movements Lateral tilt (outward tilt) Rotational movement about its vertical axis Occurs during protraction Medial tilt (return from lateral tilt, inward tilt) Occurs during retraction

Movements Shoulder joint & shoulder girdle work together Shoulder girdle movement independent Upward/downward rotation? Shoulder girdle muscles Stabilize scapula Enhance ROM of shoulder joint

ELEVATION Proximal attachment: Above or below scapula/clavicle? How many muscles fit this criteria? Upper fibers trapezius Middle fibers trapezius Rhomboids Levator Scapulae

DEPRESSION Proximal attachment: Above or below scapula/clavicle? How many muscles fit this criteria? Lower fibers trapezius Pectoralis minor Subclavius

RETRACTION Proximal attachment: In front (ribs) or behind (spine)? How many muscles fit this criteria? Trapezius (all fibers) Rhomboids Levator scapulae

PROTRACTION Proximal attachment: In front (ribs) or behind (spine)? How many muscles fit this criteria? Serratus anterior Pectoralis minor

UPWARD ROTATION Upward or downward torque? How many muscles fit this criteria? Trapezius (all fibers) Serratus anterior

DOWNWARD ROTATION Upward or downward torque? How many muscles fit this criteria? Pectoralis minor Rhomboids