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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
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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 • 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 theShoulder Girdle • Sternoclavicular • sternum (manibrum) and clavicle • arthrodial (gliding) joint • ligaments • anterior sternoclavicular ligament • posterior sternoclavicular ligament • costoclavicular ligament • interclavicular ligament
Joints of theShoulder Girdle • Acromioclavicular • Acromion Process of scapula and clavicle • arthrodial (gliding) joint • ligaments • coracoclavicular ligaments • trapezoid ligament • conoid ligament • superior & inferior acromioclavicular ligaments
Joints of theShoulder Girdle • Scapulothoracic Joint • Scapula and thoracic region • not really synovial joint • supported by muscles, not ligaments
Movements allowed bythe Shoulder Girdle • Abduction (Protraction) • Adduction (Retraction) • Inward (downward) rotation: inferior angle moves medially • Outward (upward) rotation • Depression: inferior movement • Elevation: superior movement
Muscles of theShoulder 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 • adduction • elevation • depression • outward rotation • Head • extension / hyperextension • rotation • lateral flexion
Levator Scapulae (p129) • Origin • 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 • 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 • 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 • Anterior surfaces of the 3rd - 5th ribs • Insertion • Coracoid process of scapula • Action • Rib elevation • Scapular depression
Subclavius (p133) • Origin • 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: • 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 • elevation, depression • 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