PT 112: Shoulder Anatomy PDF - Lesson 3, Study Guide

PT 112 LESSON 3: SHOULDER REGION – ANATOMY, PHYSIOLOGY, AND CONDITIONS 2ND SEMESTER - PRELIMS | A.Y. 2023-2024 | PROF. MIKO LOUIE A. YU SCAPULAR LANDMARKS...

PT 112 LESSON 3: SHOULDER REGION – ANATOMY, PHYSIOLOGY, AND CONDITIONS 2ND SEMESTER - PRELIMS | A.Y. 2023-2024 | PROF. MIKO LOUIE A. YU SCAPULAR LANDMARKS SHOULDER COMPLEX Superior Angle of the Scapula: T2 Extremely complicated region of the body Spine of Scapula: T3 High degree of mobility but not without compromising stability Inferior Angle of the Scapula: T7 ○ ↑ Mobility, ↓ Stability Normal space for medial border of the scapula: 2 Fingerbreadths Involved in overhead activities in sports and daily function ○ Susceptible to repetitive and overuse type of injuries HUMERUS ○ Overuse injuries are common Humeral Head - forms ⅓ of the sphere Movement and stabilization of the shoulder requires integrated Anatomical Neck function of the Rotator Cuff Muscles, Joint Capsule, and Scapular Surgical Neck - prone to damage Stabilizing Muscles Caff ○ Axillary nerve damage → Deltoid and Teres Minor are 6 Moving Areas for Mobility: ○ True Joints - bone to bone articulation Potator s affected Tuberosities - attachments for the rotator cuff muscles 3 degrees of freedom Bicipital Groove - passage for the Long Head of the Biceps Sternoclavicular Joint ○ “Intertubercular Groove” Acromioclavicular Joint ○ Holds the Transverse Humeral Ligament Glenohumeral Joint Yergason Test - done when the THL is torn ○ False Joints - “Functional Joints” If torn, the humeral head will pop out Bicipital Groove Radial Groove - where radial nerve passes through Subacromial ○ “Spiral Groove” Scapulohumeral Joint CLAVICLE Long slender bone that lies horizontally at the roof of the neck Orientation: ○ Middle ⅔ - convex anteriorly / concave posteriorly ○ Lateral ⅓ - convex posteriorly / concave anteriorly Transmits forces from the UE to the Axial Skeleton ○ Most commonly fractured MOI: Multiplicityof Infection (MO1) ○ Fall on outstretched hand (FOOSH) Recap: ○ Fall on shoulder (FOS) ○ Medially directed blow to shoulder Rotator Cuff Muscles: SITS Supraspinatus: Abduction First bone to ossify and the last one to complete ossification Infraspinatus: ER Costoclavicular Space - space behind clavicle and first rib Teres Minor: ER ○ Structures passing: Subclavian Artery and Brachial Plexus Subscapularis: IR ○ Only Rotator Cuff Muscle having a different action STERNOCLAVICULAR JOINT (SC JOINT) True Joint 3˚ of Freedom SCAPULA ○ Elevation/Depression Flat triangular bone that lies on the posterior thoracic wall between ○ Retraction/Protraction the 2nd and 7th ribs ○ Rotation (Posteriorly) Parts: Articulations: 1. Acromion Process - summit of the shoulder ○ Medial End of the ○ Orientation: PLS (posterior, lateral, and Clavicle superior) ○ Manubrium Sternum 2. Coracoid Process ○ Cartilage of the 1st Rib ○ Orientation: AS (anterior, superior) Joins the Appendicular Skeleton to the Axial Skeleton ○ Coracoacromial Ligament - prevents superior SC Joint + AC Joint = Humerus moves through full 180˚ abduction translation of humerus Important for shoulder flexion and abduction 3. Spine of Scapula 4. Glenoid Fossa TYPES OF ACROMION Type I - Flat (17%) ○ Least commonly injured ACROMIOCLAVICULAR JOINT (AC JOINT) Type II - Curved (43%) 3˚ of Freedom Type III - Hooked (39%) Augments the ROM of the Humerus in the Glenoid ○ 70% of Rotator Cuff Muscles are associated with a Articulations: hooked acromion ○ Acromion Process of the Scapula ○ Commonly associated with Shoulder Impingement ○ Lateral End of the Clavicle Type IV - Convex or Upturned (1%) Depends on ligaments for its strength ○ Least commonly injured LIGAMENTS OF THE AC JOINT Coracoclavicular Ligament - primary support of the AC Joint PT 112: PRINCIPLES OF PT EVALUATION LESSON 3 ace 16