Shoulder & Arm Anatomy PDF

Shoulder & Arm Shoulder and Arm Learning Objectives Recognize the surface anatomy including skin and fascial structures of the shoulder and arm. Name and locate the bones, bony landmarks, and joints for the shoulder and arm and describe the connections between them and the soft tissues of the sh...

Shoulder & Arm Shoulder and Arm Learning Objectives Recognize the surface anatomy including skin and fascial structures of the shoulder and arm. Name and locate the bones, bony landmarks, and joints for the shoulder and arm and describe the connections between them and the soft tissues of the shoulder and arm. Name and locate the muscles of the shoulder and arm, including their specific origins and insertions and the action(s) of each shoulder and arm muscle. Name and locate major joint structures of the shoulder and arm, including ligaments and bursae and common injuries of this region. © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Surface Features Visible on the Shoulder and Arm Anterior view (p. 46) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Surface Features Visible on the Shoulder and Arm Anterior/lateral view (p. 46) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Surface Features Visible on the Shoulder and Arm Posterior view (p. 46) © 2019 Books of Discovery, booksofdiscovery.com Bones Shoulder & Arm Bones of the Shoulder and Arm Anterior view Clavicle: (Collarbone) It runs horizontally across the chest. Articulates laterally with the acromion process of scapula, medially with the sternum. Scapula (Shoulder blade): Flat bone that sits on the posterior aspect of the rib cage Humerus: Upper arm. Head of the humerus forms the ball of the ball-and- socket joint. (p. 48) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Bony Landmarks of the Shoulder and Arm Scapula (Anterior view) Borders: Medial (vertebral) = red Lateral = yellow Superior = blue Angles: Superior = green Inferior = lilac Lateral angle = dark purple (pp. 49-50) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm Bony Landmarks of the Shoulder and Arm Scapula (Anterior view) Glenoid cavity: shallow cup-shaped socket, reinforced and deepened by the labrum Infraglenoid tubercle: attachment for the long head of the triceps brachii Supraglenoid tubercle: attachment point for the long head of the biceps brachii Coracoid process: hook-like projection on the anterior scapula, attachment site for pec minor, short head of biceps brachii, and coracobrachialis muscles. (pp. 49-50) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm Supraspinous fossa: depression above the Bony Landmarks of the Shoulder and Arm spine and home to the supraspinatus muscle. Scapula (posterior view) Infraspinous fossa: depression below the spine and home to the infraspinatus muscle. Spine of the scapula: a prominent ridge that separates the two posterior fossae Acromion process: bony projection of the spine that extends over the shoulder joint. Attachment for deltoid and trapezius muscles. Superior notch: an indentation on the superior border, where the suprascapular nerve passes through it. (pp. 49-50) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Bony Landmarks of the Shoulder and Arm Humerus (anterior view) Greater tubercle: Insertion point for supraspinatus, infraspinatus and teres minor Lesser tubercle: Insertion for subscapularis Intertubercular groove: Occupied by the tendon of the long head of the biceps brachii Capitulum: articulates with the radius bone of forearm Trochlea: articulates with the ulnar bone of forearm (p. 50) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Bony Landmarks of the Shoulder and Arm Humerus (posterior view) Deltoid Tuberosity: Insertion site of deltoid muscle Medial and lateral epicondyles: where medial (ulnar) and lateral (radial) collateral ligaments attach Lateral supracondylar ridge: attachment point for brachioradialis and wrist extensors (p. 50) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Bony Landmarks of the Shoulder and Arm Clavicle Conoid Tubercle: Serves as an attachment point for the conoid ligament, part of the coracoclavicular ligament, which helps stabilize the clavicle. Trapezoid Line: Serves as an attachment point for the trapezoid ligament, also part of the coracoclavicular ligament. Subclavian Groove: Provides an attachment site for the subclavius muscle, which helps stabilize the clavicle. (p. 50) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm Label the parts to the Scapula I J B C B D D N A M L K E H F F H G (p. 50) © 2019 Books of Discovery, booksofdiscovery.com  Joints and Joint Actions  Shoulder & Arm Glenohumeral Joint: A ball-and-socket joint formed between the head of the humerus and the glenoid cavity Joints of the Shoulder of the scapula. Provides the shoulder with a Glenohumeral Acromioclavicular wide range of motion, including flexion, extension, abduction, adduction, internal rotation, and external rotation. Acromioclavicular (AC) Joint: Where the clavicle meets the acromion process of the scapula. It’s a synovial joint that allows small gliding movements that adjust the positioning of the scapula, enhancing shoulder motion. (pp. 102-103) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Joints of the Shoulder Sternoclavicular A saddle-type synovial joint between the sternal end of the clavicle and the manubrium of the sternum. It is the only direct bony connection that links the upper appendicular skeleton (the appendages) and the axial skeleton. (p. 101) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Scapulothoracic joint It is actually considered a “false joint” because it doesn’t have the usual components of a joint, such as a joint capsule, synovial fluid, and articulating cartilage. (p. 101) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Movements of the Shoulder Joint Shoulder flexion and extension Flexion: movement of humerus straight anteriorly Extension: movement of humerus straight posteriorly (p. 63) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Abduction: upward lateral movement of humerus out to the side, away from body Adduction: downward movement of humerus Movements of the Shoulder Joint medially toward body from abduction Shoulder abduction and adduction (p. 64) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Horizontal abduction: movement of humerus in a horizontal or transverse plane Movements of the Shoulder Joint away from chest Shoulder horizontal abduction and horizontal adduction Horizontal adduction: movement of humerus in a horizontal or transverse plane toward & across chest (p. 63) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Movements of the Shoulder Joint Shoulder lateral rotation and medial rotation Internal rotation: movement of humerus medially around its long axis toward midline External rotation: movement of humerus laterally around its long axis away from midline (pp. 64-65) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Movements of the Scapulothoracic Joint Scapula adduction (retraction) and abduction (protraction) Adduction (retraction): scapula moves medially toward spinal column Abduction (protraction): scapula moves laterally away from spinal column (p. 66) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm Movements of the Scapulothoracic Joint Scapula upward and downward rotation Upward rotation: turning the glenoid fossa upward & moving inferior angle superolaterally away from spinal column to assist in raising arm Downward rotation: returning the inferior angle inferomedially toward spinal column & glenoid fossa to normal position (p. 66) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Scapulohumeral rhythm: for Movements of the Scapulothoracic Joint the first 30 degrees of shoulder abduction, the Scapulohumeral Rhythm scapula doesn’t rotate. After that, the inferior angle starts to move upward. There is a rhythm of the two movements occurring together: for every 2 degrees of shoulder abduction, the scapula rotates 1 degree. https://www.youtube.com/watch?v=H4nfQEeJmFo (p. 66) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm Movements of the Scapulothoracic Joint Scapular Elevation and Depression Elevation: upward or superior movement of scapula, as in shrugging shoulders Depression: downward or inferior movement of scapula, as in returning to normal position (p. 66) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Joint Actions of the Shoulder and Paired Action at the Shoulder Girdle Shoulder joint Shoulder girdle Abduction Upward rotation Adduction Downward rotation Flexion Elevation/upward rotation Extension Depression/downward rotation Internal rotation Abduction (protraction) External rotation Adduction (retraction) Horizontal extension Adduction (retraction) Horizontal flexion Abduction (protraction) (pp. 63-66) © 2019 Books of Discovery, booksofdiscovery.com Muscles Shoulder & Arm Overview Muscles that move shoulder, arm, ribs, head, neck, and elbow. (pp. 61-62) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Shoulder Muscle Group #1 Deltoid Trapezius Latissimus Dorsi Teres Major (pp. 67-73) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Deltoid A All fibers: Abduct the shoulder (glenohumeral joint) Anterior fibers: Flex the shoulder (G/H joint) Medially rotate the shoulder (G/H joint) Horizontally adduct the shoulder (G/H joint) Posterior fibers: Extend the shoulder (G/H joint) Laterally rotate the shoulder (G/H joint) Horizontally abduct the shoulder (G/H joint) O Lateral one-third of clavicle, acromion, and spine of scapula I Deltoid tuberosity N Axillary C5, 6 (pp. 67-68) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Trapezius A Upper fibers: Bilaterally: Extend the head and neck Unilaterally: Laterally flex the head and neck to the same side Rotate the head and neck to the opposite side Elevate the scapula (scapulothoracic joint) Upwardly rotate the scapula (S/T joint) Middle fibers: Adduct the scapula (S/T joint) Stabilize the scapula (S/T joint) Lower fibers: Depress the scapula (S/T joint) Upwardly rotate the scapula (S/T joint) O External occipital protuberance, medial portion of superior nuchal line of the occiput, ligamentum nuchae, and spinous processes of C-7 through T-12 I Lateral one-third of clavicle, acromion, and spine of the scapula N Spinal portion of cranial nerve XI (accessory) and ventral ramus C2, 3, 4 (pp. 68-70) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Latissimus Dorsi A Extend the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) Medially rotate the shoulder (G/H joint) O Inferior angle of scapula, spinous processes of last six thoracic vertebrae, last three or four ribs, thoracolumbar fascia, and posterior iliac crest I Intertubercular groove of the humerus N Thoracodorsal C6, 7, 8 (pp. 71-73) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Teres Major A Extend the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) Medially rotate the shoulder (G/H joint) O Inferior angle and lower one-third of lateral border of the scapula I Crest of the lesser tubercle of the humerus N Lower subscapular C5, 6, 7 (pp. 71-73) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Rotator Cuff Muscles (Group #2) Supraspinatus Infraspinatus Teres Minor Subscapularis (pp. 74-81) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Supraspinatus A Abduct the shoulder (glenohumeral joint) Stabilize the head of humerus in glenoid cavity O Supraspinous fossa of the scapula I Greater tubercle of the humerus N Suprascapular C4, 5, 6 (pp. 74-76) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Infraspinatus A Laterally rotate the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) Stabilize the head of humerus in glenoid cavity O Infraspinous fossa of the scapula I Greater tubercle of the humerus N Suprascapular C(4), 5, 6 (pp. 74-77) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Teres Minor A Laterally rotate the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) Stabilize the head of humerus in glenoid cavity O Upper two-thirds of lateral border of the scapula I Greater tubercle of the humerus N Axillary C5, 6 (pp. 74-77) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Subscapularis A Medially rotate the shoulder (glenohumeral joint) Stabilize the head of humerus in glenoid cavity O Subscapular fossa of the scapula I Lesser tubercle of the humerus N Upper and lower subscapular C5, 6, 7 (pp. 74-78) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Rotator Cuff Tendon (pp. 79-81) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Shoulder Muscle Group #3 Rhomboid Major Rhomboid Minor Levator Scapula Serratus Anterior Pectoralis Major Pectoralis Minor Subclavius (pp. 82-94) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Rhomboid Major A Adduct the scapula (scapulothoracic joint) Elevate the scapula (S/T joint) Downwardly rotate the scapula (S/T joint) O Spinous processes of T-2 to T-5 I Medial border of the scapula between the spine of the scapula and inferior angle N Dorsal scapular C4, 5 (pp. 82-83) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Rhomboid Minor A Adduct the scapula (scapulothoracic joint) Elevate the scapula (S/T joint) Downwardly rotate the scapula (S/T joint) O Spinous processes of C-7 and T-1 I Upper portion of medial border of the scapula, across from spine of the scapula N Dorsal scapular C4, 5 (pp. 82-83) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Levator Scapula A Unilaterally: Elevate the scapula (scapulothoracic joint) Downwardly rotate the scapula (S/T joint) Laterally flex the head and neck Rotate the head and neck to the same side Bilaterally: Extend the head and neck O Transverse processes of first through fourth cervical vertebrae I Medial border of scapula, between superior angle and superior portion of spine of scapula N Cervical 3, 4, and dorsal scapular C4, 5 (pp. 83-85) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Serratus Anterior A With the origin fixed: Abduct the scapula (scapulothoracic joint) Upwardly rotate the scapula (S/T joint) Depress the scapula (S/T joint) Hold the medial border of the scapula against the rib cage With the scapula fixed: May act to elevate the thorax during forced inhalation O External surfaces of upper eight or nine ribs I Anterior surface of medial border of the scapula N Long thoracic C5, 6, 7, 8 (pp. 86-88) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Pectoralis Major A All fibers: Adduct the shoulder (glenohumeral joint) Medially rotate the shoulder (G/H joint) Assist to elevate the thorax during forced inhalation (with the arm fixed) Upper fibers: Flex the shoulder (G/H joint) Horizontally adduct the shoulder (G/H joint) Lower fibers: Extend the shoulder (G/H joint) O Medial half of clavicle, sternum, and cartilage of first through sixth ribs I Crest of greater tubercle of humerus N Upper fibers: Lateral pectoral C5, 6, 7 Lower fibers: Lateral and medial pectoral C6, 7, 8, T1 (pp. 89-91) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Pectoralis Minor A Depress the scapula (scapulothoracic joint) Abduct the scapula (S/T joint) Downwardly rotate the scapula (S/T joint) With the scapula fixed: Assist to elevate the thorax during forced inhalation O Third, fourth, and fifth ribs I Medial surface of coracoid process of the scapula N Medial pectoral, with fibers from a communicating branch of the lateral pectoral C(6), 7, 8, T1 (pp. 92-93) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Subclavius A Depress the clavicle and draw it anteriorly Elevate the first rib (to assist during inhalation) Stabilize the sternoclavicular joint O First rib and cartilage I Inferior surface of middle one-third of clavicle N Subclavian C5, 6 (p. 94) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Shoulder Muscle Group #4 Biceps Brachii Triceps Brachii Coracobrachialis (pp. 95-99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Biceps Brachii A Flex the elbow (humeroulnar joint) Supinate the forearm (radioulnar joints) Flex the shoulder (glenohumeral joint) O Short head: Coracoid process of scapula Long head: Supraglenoid tubercle of scapula I Tuberosity of the radius and aponeurosis of the biceps brachii N Musculocutaneous C5, 6 (pp. 95-96) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Triceps Brachii A All heads: Extend the elbow (humeroulnar joint) Long head: Extend the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) O Long head: Infraglenoid tubercle of the scapula Lateral head: Posterior surface of proximal half of the humerus Medial head: Posterior surface of distal half of the humerus I Olecranon process of the ulna N Radial C6, 7, 8, T1 (pp. 97-98) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Coracobrachialis A Flex the shoulder (glenohumeral joint) Adduct the shoulder (G/H joint) O Coracoid process of the scapula I Medial surface of mid-humeral shaft N Musculocutaneous C6, 7 (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #1. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #2. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #3. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #4. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #5. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm #6. Name the muscle! (p. 99) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Look How Far You’ve Traveled © 2019 Books of Discovery, booksofdiscovery.com Ligaments & other structures Shoulder & Arm Axilla Structures of the Axilla (pp. 100-101) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Ligaments of the Shoulder The three glenohumeral ligaments: Superior Middle Inferior The inferior is most important for stabilizing the abducted or externally rotated shoulder. (p. 102) © 2019 Books of Discovery, booksofdiscovery.com  Shoulder & Arm 1. Coracohumeral: stabilizes the humeral head by connecting it to the coracoid Ligaments of the Shoulder process 2. Coracoacromial: makes an arch 3 4 between the coracoid and acromial processes of the scapula 3. Acromioclavicular: connects the 2 acromion process to the clavicle, supporting the AC joint 1 4. Coracoclavicular: connects the coracoid process to the clavicle. Has two parts (trapezoid and conoid ligaments) (p. 102) © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Nerves of the Shoulder All shoulder joint muscles are innervated from the brachial plexus. (p. 102) © 2019 Books of Discovery, booksofdiscovery.com Common Injuries Shoulder & Arm Rotator Cuff Injuries Supraspinatus attach to greater tubercle from above (Abduct) Infraspinatus attach to greater tubercle posteriorly (Ext. Rot.) Teres Minor – attach to greater tubercle posteriorly (Ext. Rot.) Subscapularis – attach to lesser tubercle anterior (Int. Rot.) These small muscles cover the head of the humerus and attach it to the scapula. They can sometimes get overworked or impinged in the subacromial space. © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Shoulder Subluxation and Dislocation A wide range of motion of the shoulder joint in many different planes requires a significant amount of laxity. The price of greater mobility is reduced stability, so a shoulder can dislocate or sublux (partially dislocate). © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Labrum Tear The glenoid labrum is a fibrocartilaginous rim around the glenoid cavity that deepens the glenoid fossa, provides cushioning, and slightly enhances stability of the joint. Superior Labrum, Anterior to Posterior tears (SLAP tears), also known as labrum tears can occur from acute trauma (falling on an outstretched arm) or from repetitive shoulder motion (throwing athletes). © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm Winged Scapula This is a postural condition where the medial border of the scapula is prominent and peels away from the rib cage to visibly protrude posteriorly. It is often due to a weak serratus anterior but can involve other muscles like a tight pec minor. © 2019 Books of Discovery, booksofdiscovery.com Shoulder & Arm End of the Trail Thank you! © 2019 Books of Discovery, booksofdiscovery.com