Unit 5. Shoulder Anatomy PDF

KINESIOLOGY SHOULDER JOINT  INTRODUCTION Most mobile and unstable Wide range of motion Muscles work as a "team" to produce coordinated action SCAPULOHUMERAL RITHM 2  INTRODUCTION Joints in the shoulder complex...

KINESIOLOGY SHOULDER JOINT  INTRODUCTION Most mobile and unstable Wide range of motion Muscles work as a "team" to produce coordinated action SCAPULOHUMERAL RITHM 2  INTRODUCTION Joints in the shoulder complex First group scapulohumeral joint (glenohumeral) (GHj) subdeltoid joint Second Group scapulothoracic joint (STj) acromioclavicular joint (ACj) sternocostoclavicular joint (ACCj) 3  FIRST GROUP: GLENOHUMERAL J. Ball and Socket Incongruous articulation, poor intrinsic stability Static or primary stabilizers – joint capsule – ligamentous complex – glenoid labrum Secondary or dynamic stabilizers – Rotator cuff 4 FIRST GROUP: GLENOHUMERAL J Movements in 3 planes: – Flexion / Extension – abduction / adduction – Internal / external rotation + Horizontal abduction / adduction 5 FIRST GROUP: SUBDELTOID J. Anatomical false joint True Physiological Joint Important in movement ABD shoulder subacromial bursa avoids friction 6  SECOND GROUP: SCAPULOTHORACIC J. Anatomical false joint True Physiological Joint 2 slip planes are: – omoserratic space – Thoracoserratic space 7  SECOND GROUP: SCAPULOTHORACIC J. Great shoulder width thanks to this joint. – Protraction and retraction : 15cm – Elevation and depression: 10-12cm – Upward and downward rotation: 60º 8  SECOND GROUP: ACROMIOCLAVICULAR J. Plane joint Sliding movements. Limited by Coronoid and Trapezoid Ligaments 9 SECOND GROUP: STERNOCOSTOCLAVICULAR J. Saddle Joint Articular disc divides the cavity Slide an Roll 10 GENERAL OSTEOKINEMATICS From neutral position of GLENOHUMERAL joint Implication of ST, AC and SCC Movement ROM Flexion 180º Extension 45º-55º ABDuction 180º ADDuction 45º internal rotation 75º-85º external rotation 60º-70º 11 GLENOHUMERAL KINEMATICS FLEXION-EXTENSION Fixed point: glenoid twist No rolling or slide: posterior spining Anterior translation due to posterior capsular tension 12 GLENOHUMERAL KINEMATICS. ABD / ADD Cranial roll of the head while gliding downwards Add → opposite direction 13  GLENOHUMERAL KINEMATICS. ABD / ADD Importance of the supraspinatus action Without abd slide, the roll compress the humerus against the coracoacromial arch: subacromial impingement 14  GLENOHUMERAL KINEMATICS. ABD / ADD ABD FRONTAL PLANE vs SCAPULAR PLANE Sagittal not natural or functional. - Front Plane abd. Difficulty in reaching full ROM due to compression structures. - Scapular Plane Abd No structural compression. More efficient supraspinatus action 15 GLENOHUMERAL KINEMATICS. Internal and External Rotation ER: The head rolls posterior and glides anterior IR in the opposite way Simultaneous glide and roll allows head to roll over a smaller surface 16 GLENOHUMERAL JOINT ARTHROKINEMATICS: SUMMARY Convex rule in open kinetic chain Osteokinematic (OKC) Arthrokinematic (glide) Flexion Posterior spin Extension Anterior spin Abduction Inferior Aduction Superior Internal Rotation Posterior External Rotation Anterior Horizontal ABD Anterior Horizontal ADD Posterior 17  AC and SCC KINEMATICS Only passive movements All scapular movement = clavicular movement (AC and SCC) Allow for wider ROM added to glenohumeral motion For example: shoulder abduction (Total of 180º): – 60º lateral (upward rotation) of the scapula: 20º Acromioclavicular + 40º Sternoclavicular 18  AC JOINT STABILIZERS Static. – Joint capsule: reinforced by capsular ligaments – Ligaments: Cononoid and Trapezoid ligaments. In addition to the acromioclavicular that reinforces the joint capsule – articular disc Dynamic. – Deltoid and upper trapezius muscles 19  AC OSTEOKINEMATICS Upward and downward rotation Rotations adjustments in the horizontal plane Rotations adjustments in the sagittal plane 20  SCC JOINT STABILIZERS Static. – Fibrous capsule – Ligaments: anterior and posterior sternoclavicular, the costoclavicular on each side, and the midline interclavicular. – Articular disc Dynamic. – There are not many muscles around – Subclavius muscle 21 SCC OSTEOKINEMATICS 22  SCC ARTHROKINEMATICS Elevation-depression: convex rule Protraction-retraction: concave rule??? ? ? 23  SCAPULOTHORACIC JOINT Larger shoulder amplitude thanks to ST AC and SCC movement allow for ST motion 24 SCAPULOTHORACIC JOINT. Elevation and depression Elevation – SCC and AC – Scapula follows path of clavicle Opposite for depression 25  SCAPULOTHORACIC JOINT. Protraction and Retraction Protraction – Horizontal plane rotations of SCC and AC – Scapula follows clavicle path Opposite for retraction 26  SCAPULOTHORACIC JOINT. Rotations Upward rotation – Arm raise – Sum of SCC elevation and AC upward rotation 27  SCAPULOTHORACIC JOINT. Rotations Downward rotation – arm comes back – Sum of SCC depression and downward rotation AC 28  KINETICS MUSCULAR ACTIONS – Proximal stabilizers – Distal mobilizers Optimal function of the entire shoulder complex is based on the functional interdependence between the proximal stabilizers and the distal mobilizers. Proximal control = effective distal movement 29 GLOBAL FLEXION FIRST Stage. 0-30º/60º. GH motor muscles: – anterior deltoids – Coracobrachialis – Clavicular pectoralis major Movement limits. − Coracohumeral ligament strain 30 GLOBAL FLEXION SECOND Stage. 30º/60º-120º. STj Upward rotation of the scapula ACj and SCCj Participation motor muscles (+ previous): – serratus major – upper trapezius Movement limits: – latissimus dorsi – pectoralis major. 31  GLOBAL FLEXION THIRD Stage. 120º-180º Shoulder joint lock Spinal intervention begins In ipsilateral flexion, it produces contralateral lat. flex. – Contraction spinal muscles opposite side In bilateral flexion, it produces lumbar lordosis. – Bilateral lumbar spinal contraction. 32  EXTENSION 45º-55º Involved: scapulohumeral and scapulothoracic. – Scapulohumeral motor muscles. Post. deltoid, teres major and minor – Scapulothoracic motor muscles (downward rotation and adduction) – Rhomboids – Middle trapezius – Latissimus dorsi. 33 GLOBAL ABDUCTION FIRST Stage. 0º-90º. motor muscles: – Deltoids, especially the middle fasciculus and supraspinatus. – Plane of the scapula (30º of flexion). 34  GLOBAL ABDUCTION SECOND Stage. 90º-150º Upward rotation of Scapula orienting glenoids Axial rotation AC and SCC motor muscles – Serratus and Upper Trapezius movement limits – Maximum reached in the scapula and resistance of the adductor muscles 35 GLOBAL ABDUCTION THIRD Stage. 150º-180º contralateral tilt of the spine due to contraction of the spinal muscles of the opposite side the spinal muscles contract bilaterally, producing a lumbar hyperlordosis 36 GLOBAL ADDUCTION 30º-45º When arm is in ABD → the ADD is made by eccentric contraction of ABD muscles. Motor muscles. – GHj flex. Pectoralis Major and Anterior Deltoid – GHj extension. Teres major and minor, Latissimus dorsi – STj flex. serratus major – STj extension. rhomboids 37 EXTERNAL ROTATION 60º-70º motor muscles: – Infraspinatus and teres minor. The movement of scapular adduction is added by the action of the Rhomboids and the middle portion of the Trapezius. 38 INTERNAL ROTATION 75º-85º motor muscles: – Teres major – Latissimus dorsi – Subscapularis – Pectoralis Major The abduction movement of the scapula is added to the Serratus Major and Pectoralis Minor action 39 MOVEMENT LIMITS LIGAMENTS – CORACOHUMERAL LIGAMENT – GLENOHUMERAL LIGAMENT 40 CORACOHUMERAL LIGAMENT Lesser Tubercle fasciculus → extensión Greater tubercle fasciculus → flexión Abduction → relaxes and in adduction→ Tension External rotation →Tension and internal rotation → relaxation 41  GLENOHUMERAL LIGAMENT ABD → Tension in lower and middle fascicles ADD → relaxes the superior fascicle – If movement is in the plane of the scapula, the tension of the fascicles of the ligament is delayed and the amplitude of Abduction in the glenohumeral increases up to 110º External rotation → tenses all three fascicles and internal rotation relaxes all Global relaxation in flexion and tension in extension 42  MUSCULAR ACTIONS 1. MUSCLES OF THE SCAPULOTHORACIC JOINT 2. MUSCLES THAT ELEVATE THE ARM 3. MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER 4. MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER 43  MUSCLES OF THE SCAPULOTHORACIC JOINT ELEVATORS Upper trapezius levator scapulae Rhomboids ideal posture 44  MUSCLES OF THE SCAPULOTHORACIC JOINT ST JOINT DEPRESSORS lower trapezius latissimus dorsi Pectoral Minor subclavius 45 MUSCLES OF THE SCAPULOTHORACIC JOINT ST JOINT DEPRESSORS ????? 46  MUSCLES OF THE SCAPULOTHORACIC JOINT ST JOINT PROTRACTORS Serratus major Rotation axis SCC 47  MUSCLES OF THE SCAPULOTHORACIC JOINT ST JOINT RETRACTORS Middle trapezius + Rhomboids and lower trapezius – – rowing, climbing – They are synergists and antagonists.  MUSCLES OF THE SCAPULOTHORACIC JOINT ST UPWARD AND DOWNWARD ROTATORS The muscles that perform these actions are discussed below in the context of movement of the entire shoulder. 49  MUSCULAR ACTIONS 1. MUSCLES OF THE SCAPULOTHORACIC JOINT 2. MUSCLES THAT ELEVATE THE ARM 3. MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER 4. MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER 50  MUSCLES THAT ELEVATE THE ARM Deltoid Supraspinatus GH Muscles Coracobrachialis Long head of bíceps Serratus anterior ST Muscles Trapezius Subscapularis Supraspinatus Rotator Cuff Muscles Infraspinatus 56 Teres minor  GH Muscles ABD – Anterior and middle deltoids – Supraspinatus Flexión – Anterior deltoids – Coracobrachialis – biceps long head 52  ST Muscles Serratus anterior Upper trapezius – Move the scapula and make a stable point for distal mobilizers Deltoid and Supraspinatus Axis, muscle fibers lever action 53  Rotator Cuff Muscles FUNCTIONS: 1. Dynamic joint stability regulators 2. Arthrokinematics Controllers 54  Rotator Cuff Muscles FUNCTIONS: 1. Dynamic joint stability regulators – Mobile GH = cuff stabilizes – Anatomical organization makes protective cuff – Stabilize and center the glenoid head 55  Rotator Cuff Muscles FUNCTIONS: 2. Arthrokinematics Controllers – Coaptation force – Without the force of the supraspinatus, the predominant action of the deltoids = impingement of the head with the acromion 56  MUSCULAR ACTIONS 1. MUSCLES OF THE SCAPULOTHORACIC JOINT 2. MUSCLES THAT ELEVATE THE ARM 3. MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER 4. MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER 57 MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER Major isometric moment of the shoulder – agonists. Latissimus dorsi and sternocostal portion pectoralis major (major extensors and add of the shoulder) – Synergist. Teres major, triceps long head, posterior deltoid, infraspinatus and teres minor. 58  MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER Rhomboids stabilize scapula in ADD and GH extension. Retraction and downward rotation All rotator cuff is active during this movement. 59  MUSCULAR ACTIONS 1. MUSCLES OF THE SCAPULOTHORACIC JOINT 2. MUSCLES THAT ELEVATE THE ARM 3. MUSCLES THAT MOVE IN ADD AND EXTEND THE SHOULDER 4. MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER 60  MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER INTERNAL ROTATORS Subscapularis, anterior deltoid, pectoralis major, latissimus dorsi, and teres minor +IR and – ER Head Roll and slides over glenoid 61  MUSCLES THAT INTERNALLY AND EXTERNALLY ROTATE THE SHOULDER EXTERNAL ROTATORS infraspinatus, teres minor, and the posterior portion of the posterior deltoid Supraspinatus synergist -ER + IRI concentric and eccentric 62