Shoulder Girdle KIN 245

Bones of the Shoulder Girdle Scapula (shoulder) Clavicle (small key) Link to Axial skeleton via sternoclavicular joint (an anterior joint) Lack of posterior attachment to the axial skeleton allows for a wide ROM Functions to allow attachment areas for numerous muscles that move the shoulder and elbow

Landmarks Borders Angles Acromion process Spine of scapula superior, medial, lateral Angles inferior, superior Acromion process Spine of scapula Glenoid fossa Coracoid process (like a crow’s beak) Supraspinatus, Infraspinatus, Subscapular fossa

Joints of the Shoulder Girdle Sternoclavicular sternum (manibrum) and clavicle arthrodial (gliding) joint ligaments anterior sternoclavicular ligament posterior sternoclavicular ligament costoclavicular ligament interclavicular ligament

Joints of the Shoulder Girdle Acromioclavicular Acromion Process of scapula and clavicle arthrodial (gliding) joint ligaments coracoclavicular ligaments trapezoid ligament conoid ligament superior & inferior acromioclavicular ligaments

Joints of the Shoulder Girdle Scapulothoracic Joint Scapula and thoracic region not really synovial joint supported by muscles, not ligaments

Movements allowed by the Shoulder Girdle Abduction (Protraction) Adduction (Retraction) Inward (downward) rotation: inferior angle moves medially Outward (upward) rotation Depression: inferior movement Elevation: superior movement

Muscles of the Shoulder Girdle Posterior trapezius levator scapula rhomboids (major and minor) Anterior pectoralis minor seratus anterior subclavius

Trapezius (p134) Origin: Superior nuchal line Occipital protuberance Ligamentum nuchae C7 and T12 vetebrae

Trapezius Insertion Lateral 1/3 of clavicle Acromion process of scapula Spine of scapula

Trapezius Action Scapula Head adduction elevation depression outward rotation Head extension / hyperextension rotation lateral flexion

Levator Scapulae (p129) Origin Insertion Action Transverse processes of the 1st four cervical vertebrae Insertion Vertebral (medial) border of the scapula above base of scapular spine Action Scapula elevation, inward rotation, adduction

Rhomboid Muscles (p131) Origin Insertion Lower part of ligamentum nuchae Spinous process of the 7th cervical and 1st five thoracic vert. Insertion Vertebral border of the scapula

Rhomboid Muscles Action Scapular adduction inward rotation elevation

Serratus Anterior (p132) Origin Insertion lateral, anterior surface of the upper 8/9 ribs Insertion Anterior aspect of the vertebral border of the scapula

Serratus Anterior Action Scapular abduction outward rotation depression

Pectoralis Minor (p130) Origin Insertion Action Anterior surfaces of the 3rd - 5th ribs Insertion Coracoid process of scapula Action Rib elevation Scapular depression

Subclavius (p133) Origin Insertion Action Superior aspect of 1st rib (around costal cartilage) Insertion Inferior groove mid-portion of clavicle Action scapular depression stabilization of sternoclavicular jt.

Summary Shoulder Girdle bones: clavicle, scapula joints: muscles sternoclavicular acromioclavicular scapulothoracic muscles anterior: pectoralis minor, serratus anterior, subclavius posterior: levator scapulae, rhomboids, trapezius

Shoulder Girdle The arm travels through a wide range of movements, the scapula cooperates by placing the glenoid fossa in the most favorable position for the head of the humerus (scapulohumeral rhythm)

Movements of the Shoulder Girdle Clavicle elevation, depression protraction, retraction (or forward and backward horizontal movements) Scapula abduction, adduction inward and outward rotation

Muscle Analysis Chart Identify muscles that move the scapula abduction adduction elevation depression upward rotation downward rotation

Muscles that move the scapula abduction serratus anterior pectoralis minor adduction trapezius (middle and lower fibers) rhomboids

Muscles that move the scapula elevation trapezius (upper & middle fibers) levator scapulae rhomboids (slight) depression trapezius (lower fibers) pectoralis minor subclavius (clavicle depression)

Muscles that move the scapula outward rotation trapezius (middle and lower fibers) serratus anterior inward rotation rhomboids Levator scapulae