Shoulder Anatomy and Physiology REVIEW Mr. Brewer

Boney Anatomy Major Points: 4 Bones: - Humerus (Upper Arm Bone) - Scapula (Shoulder Blade) - Clavicle (Collar Bone) - Sternum (Breast Plate/Bone) 4 Joints: - AC Joint (Acromioclavicular) - SC Joint (Sternoclavicular) - Glenohumeral Joint (“Shoulder Joint”) - Scapulothoracic Joint (Considered a “False Joint”) Structures: - Glenoid Labrum Bursa: - Subdeltoid Bursa - Subscapular Bursa - Subacromion Bursa - Subcoracoid Bursa

Boney Landmarks Humeral Landmarks: Greater Tubercle Lesser Tubercle Bicipital Groove Olecranon Process Head of the Humerus *NOTE: The bicipital groove is formed by the Greater and Lesser Tubercles and guides the biceps tendon to it’s insertion point on the glenoid and labrum.

Boney Landmarks Clavicle Landmarks: Sternal End Middle 1/3 Acromial end *NOTE: Middle 1/3 is the most vulnerable part of the clavicle for a fracture. *NOTE the STERNAL end is more stable and secure, thus less likely to be injured than the Acromial end.

Boney Landmarks Scapula: - Spine of the Scapula - Inferior Angle - Lateral Border - Medial Border - Acromion Process - Coracoid Process - Glenoid Fossa

Scapula Continued Key Points: Spine of the Scapula separates the supraspinous surface from the infraspinous surface on the posterior(dorsal) surface. The Glenoid Fossa is a cavity that provides a smooth area for the head of the Humerus to articulate with, while allowing a wide range of motion. Sitting on the Glenoid Fossa is the LABRUM. The Labrum acts as shock absorber, reduces bone-to-bone wear and tear, and also provides additional depth to the cavity to allow the head of the Humerus to sit with more stability on the glenoid.

Boney Landmarks Sternum 3 Major Parts: Manubrium Body Xiphoid Process

Structures Glenoid Labrum Acts as a shock absorber. Reduces bone-to-bone contact Provides additional depth of the joint for stability. LONG HEAD of the Biceps attaches to the superior aspect of the Glenoid Fossa AND the Glenoid Labrum. Fibers of the Long Head of the Biceps form the Labrum.

Miscellaneous Facts The SC joint (Sternoclavicular) is much more stable and secure than the AC joint (Acromioclavicular). When you refer to a “separarted shoulder”, it is the AC joint that is affected.

Muscles Elbow Movements: Elbow Flexion: Biceps Brachii Brachioradialis Brachialis Elbow Extension: - Triceps Flexion Extension

Muscles Shoulder Flexion: Anterior Deltoid Shoulder Extension: - Posterior Deltoid

Muscles Shoulder Adduction: Shoulder Abduction: Latissimus Dorsi (Lat) Lat Pulldown Shoulder Adduction: Latissimus Dorsi (Lat) Shoulder Abduction: SUPRASPINATUS Only Rotator Cuff Muscle to act primarily as a shoulder abduction. Typically done at 45 degrees of horizontal adduction as well.

Muscles Internal Rotation: External Rotation: Subscapularis Infraspinatus Teres Minor Internal Rotation

Scapular Movements Scapular Elevation: Scapular Depression: Levator Scap Upper Trapezius Scapular Depression: Lower Trapezius Scapular Retraction: Rhomboids (Major and Minor) Scapular Protraction: Serratus Anterior