Therapeutic Kinesiology:Musculoskeletal Systems, Palpation, and Body Mechanics

Therapeutic Kinesiology Instructor Manual: Ch16 p.1 TK INSTRUCTOR MANUAL: CHAPTER 16 The Shoulder Girdle Chapter manuals include: Objectives Lecture Notes Suggested Classroom and Student Development Activities For other chapter-by-chapter resources, see: Key Term Quizzes Muscle Origin and Insertion Worksheets Muscle OIAs List by Chapter MyTest Test Bank For additional resources see “Teaching Tips and Tools”: 7 research-based learning principles for kinesiology courses in massage 5-step self-directed learning cycle for body mechanics courses Tools that build metacognitive skills: e.g., concept (mind) maps, grading rubrics, and self-assessments inventories OBJECTIVES List and describe the bony landmarks on the four bones making up the shoulder girdle. Demonstrate the palpation of the bony landmarks of the shoulder girdle. List four joints in the shoulder girdle and their classifications and range of motion. Name the major ligaments of the shoulder girdle and the location and function of each one. Describe and contrast two injuries—a shoulder dislocation and a shoulder separation. Describe the structure and function of the coracoacromial arch. Describe the neutral position of the shoulder girdle and the criteria for scapula neutral. Define scaption and describe how it relates to efficient arm movement. Define and describe the scapulohumeral rhythm. Identify the origins, insertions, and actions of the muscles of the scapula and shoulder. Identify trigger point locations and pain referral patterns for the scapula and shoulder muscles. Demonstrate the active movement and palpation of each scapula and shoulder muscle. LECTURE NOTES BONES OF THE SHOULDER GIRDLE Introduction A bony yoke suspended by muscular tensions Suspends arms laterally for free swinging motion Allows mobility and articulation of arms Shoulder girdle alignment requires: Maintaining neutral alignment of girdle Balancing muscular pulls that support girdle Coordinating optimal muscle firing sequence Bones of the shoulder girdle Humeri (singular: humerus) Clavicles Scapulae Bony landmarks of humerus relative to shoulders Head of humerus Greater tubercle Lesser tubercle Deltoid tuberosity Clavicle A round, S-shaped bone Provides horizontal struts across shoulder yoke Provides attachment sites for muscles Most frequently broken bone in body Scapula Flat, irregular triangular bone; the "shoulder blade" Bony landmarks of the scapula Coracoid process Acromion process Spine of the scapula Infraspinous fossa, supraspinous fossa, subscapular fossa Inferior angle and superior angle Lateral border, medial border, superior border Supraglenoid tubercle and infraglenoid tubercle Glenoid fossa JOINTS AND LIGAMENTS OF SHOULDER GIRDLE Linked movement of four joints allows arm/hand mobility Glenohumeral joint Acromioclavicular joint Sternoclavicular joint Scapulothoracic joint Glenohumeral (GH) joint: Ball-and-socket joint Between glenoid fossa and humeral head Most mobile, least stable joint in body Glenoid labrum deepens joint, stabilizes shallow socket Glenohumeral ligament: Cuff encasing joint capsule Lax in neutral position (with arm hanging) Taut in abduction (closed-packed position) Subdeltoid space Between GH joint and acromion process Cushioned by subdeltoid bursa and subacromial bursa Protects underlying supraspinatus and biceps brachii tendons Coracohumeral ligament spans anterior border Runs from coracoid process to greater tubercle Limits GH hyperextension and lateral rotation Prevents inferior dislocation of GH joint Glenohumeral joint motion Flexion: 180 degrees Hyperextension: 45 degrees Medial rotation: 70 degrees Lateral rotation: 90 degrees Abduction: 180 degrees Adduction: 30 degrees Horizontal adduction and abduction Circumduction Combination of movement in all three planes Inscribes a cone-like shape GH can circumduct in all three planes Common GH joint injury: Shoulder dislocation Humeral head is pulled out of socket From severe overstretching, falls, ballistic movement Most common dislocation in inferior direction Can also dislocate posteriorly or anteriorly Once dislocated, easy to reinjure, usually reoccurs Scapulothoracic joint Not a true anatomic joint Articulating space between scapula and ribs Moves with acromioclavicular and sternoclavicular joints Increases range of motion of GH joint Range of motion Elevation and depression Protraction and retraction Upward and downward rotation Anterior tilt Acromioclavicular (AC) joint: Plane synovial joint Between lateral clavicle and acromion process Gliding motion Allows independent motion between scapula and clavicle Provides horizontal stabilization of shoulder Acromioclavicular ligaments Superior acromioclavicular (AC) ligament Inferior acromioclavicular (AC) ligament Coracoacromial ligament Coracoclavicular ligament: Two parts Trapezoid ligament Conoid ligament Common AC joint injury: Shoulder separation Occurs during falling, impact accidents Falling on an outstretched hand (FOOSH) Impact thrusts shoulder into elevation Impact falls result in varying degrees of separation Grade 1: minor ligamentous strain Grade 2: partial ligamentous tear Grade 3: complete ligamentous rupture, separation of joint surfaces Sternoclavicular (SC) joint: Plane synovial joint Between medial clavicle, first rib, manubrium Gliding motion Only joint connecting shoulder girdle to axial skeleton Articulating disk absorbs impact, reduces friction Stabilized by sternoclavicular and costoclavicular ligaments Neutral position of scapula Position of optimal alignment Markers of scapula neutral position Medial scapular border parallel to spine Medial scapular border 56 cm lateral to spine Scapula rests flat against thorax Superior angle higher than acromion, level with T-1 Medial spine of scapula level with T-3 Inferior angle of scapula level with T-7 or T-8 Scaption and shoulder abduction Scaption: Plane determined by direction glenoid fossa faces Plane of scaption 30 degrees from frontal plane Abduction in plane of scaption more efficient Problems with abduction in frontal plane Retracts scapular Can impinge subacromial space Shoulder abduction requires following actions: GH joint flexes and laterally rotates Scapula upwardly rotates Clavicle laterally rotates and elevates Scapulohumeral rhythm Ratio of movement between GH/scapulothoracic joints Measure of scapular stability Measure of coordinated muscle firing sequence Markers of ideal rhythm Scapula stable until 90 degrees of GH flexion Scapula stable until 60 degrees of GH abduction Scapula moves with humerus in about 1-to-2 ratio Adhesive capsulitis Abnormal thickening/inflammation of GH joint capsule Adheres shoulder ligaments and tendons Also called "frozen shoulder" due to restriction of GH abduction Painful arc with lateral rotation/abduction of GH More prevalent in women, has an emotional component Cause unknown, can occur after shoulder injury MUSCLES OF THE SHOULDER GIRDLE Overview Extrinsic muscles of posterior shoulder Rotator cuff muscles Scapular muscles Primary shoulder flexors and adductors Primary shoulder abductors Extrinsic muscles of posterior shoulder Trapezius: Different functions in upper, middle, and lower O: External occipital protuberance, superior nuchal line, nuchal ligament, SPs C7 to T12 I: Lateral third of clavicle, acromion process, and spine of scapula A: Elevates, depresses, retracts, and upwardly rotates scapula; bilaterally extends head; unilaterally side-bends head and neck to same side; rotates head/neck to opposite side Latissimus dorsi: "Swimmer's muscle," only muscle that attaches arms to pelvis O: Spinous processes of T-7 to L-5, sacrum, posterior iliac crest, and bottom ribs I: Medial lip of bicipital groove A: Adducts, extends, and medially rotates shoulder; depresses shoulder girdle and retracts scapula Teres major: "Lat's little helper" O: Lower third of posterior, lateral border of scapula I: Medial lip of bicipital groove A: Assists adduction, medial rotation, and extension of shoulder Rotator cuff muscles Tendons encapsulate GH, stabilizes ball in socket Supraspinatus: Always under load, prevents GH downward displacement O: Supraspinous fossa I: Greater tubercle of humerus A: Abducts GH joint, stabilizes head of humerus in glenoid fossa Infraspinatus: Fibrous multipennate muscle O: Infraspinous fossa I: Middle facet of greater tubercle of humerus A: Laterally rotates /adducts GH joint, stabilizes humeral head in glenoid fossa Subscapularis: Fibrous multipennate muscle O: Subscapular fossa I: Lesser tubercle of humerus A: Medially rotates GH joint, stabilizes head of humerus in glenoid fossa Teres minor O: Upper two-thirds of lateral, posterior surface of scapula I: Greater tubercle of humerus A: Laterally rotates and adducts GH joint, stabilizes head of humerus in glenoid fossa Scapular muscles (Figure 16.48) Rhomboid major and minor: Parallelogram-shaped, antagonists to serratus anterior O: Minor on spinous processes of C7 to T1, major on SPs of T2 to T5 I: Medial border of scapula A: Retracts and downwardly rotates scapula Serratus anterior: Called the "finger muscle" O: Lateral surfaces of 1st to 9th ribs I: Anterior side of superior angle, medial border, and inferior angle of scapula A: Protracts and stabilizes scapula, assists GH joint flexion and adduction, assists upward scapular rotation, lower fibers depress scapula, upper fibers elevate scapula Levator scapula: Often dysfunctional with trigger points O: Transverse processes of C1 to C4 I: Superior angle of scapula (medial aspect) A: Elevates scapula when neck is fixed, side-bends neck when scapula is fixed Scapular winging Faulty pattern: Medial scapula border lifted From serratus anterior weakness, inhibition, or paralysis Two types True winging: entire medial border raised. Pseudo-winging: part of medial border raised. Primary shoulder flexors and adductors Pectoralis major: Large chest muscle O: Clavicular head – Medial half of clavicle Sternal head – Sternum and cartilage of 2nd to 7th ribs Abdominal head – Aponeurosis of external oblique and medial portion of costal arch I: Lateral lip of bicipital groove A: Adducts and medially rotates glenohumeral (GH) joint; clavicular head flexes GH joint; sternal head extends GH joint, assists elevation of thorax when shoulder is fixed Pectoralis minor: Crosses brachial plexus, tightness can impinge nerves O: Anterior surfaces of 3rd, 4th, and 5th ribs I: Coracoid process of scapula A: Elevates upper ribs when scapula is fixed, tilts scapula when ribs are depressed Subclavius: Small, anterior clavicular stabilizer O: Inferior surface of middle clavicle I: Medial aspect of 1st rib A: Stabilizes sternoclavicular joint, depresses clavicle Primary shoulder abductors Deltoid: Thick, fleshy muscle that caps shoulder O: Lateral third of clavicle, lateral edge of acromion process, lateral half of scapular spine I: Deltoid tuberosity A: Abducts, adducts, flexes, and extends shoulder Coracobrachialis: Anterior border of armpit O: Coracoid process of scapula I: Anteromedial shaft of humerus I: Assists shoulder flexion and adduction SUGGESTED CLASSROOM AND STUDENT DEVELOPMENT ACTIVITIES PROVIDE AN OVERVIEW OF THE CLASS Before class, write a short schematic overview of the class on the board, then go over it at the beginning of class. For example: Today's class covers: Bones of the shoulder Joints and ligaments Muscles of shoulder Activities: Review, lecture and assessments, palpation exercises, recap PALPATION EXERCISES Bony landmarks of the shoulder girdle (p. 552) Scapula (p. 555) Acromioclavicular and sternoclavicular joints (p. 567) Trapezius, latissimus dorsi, and teres major (p. 577) Rotator cuff: supraspinatus, infraspinatus, subscapularis, and teres minor (p. 583) Rhomboids, serratus anterior, and levator scapula (p. 588) Pectoralis major, pectoralis minor, and subclavius (p. 595) Deltoid and coracobrachialis (p. 600) EXPLORING TECHNIQUE EXERCISE Passive range of motion for the shoulder (p. 562) Assessing the neutral position of the shoulder girdle (p. 570) Treating the levator scapula (p. 591) SELF-CARE EXERCISES Neuromuscular patterning for the scapulohumeral rhythm (p. 572) Stretching the levator scapula (p. 588) Stretching the pectoralis muscles (p. 597) Finding scapula neutral (p. 602) © 2013 by Education, Inc. Foster, Instructor Resources for Therapeutic Kinesiology