Shoulder WWAMI

The Shoulder Region : 

The Shoulder Region March 10th, 2010 Dan Topping, MD dtopping@wsu.edu

Objectives for the lecture are to learn… : 

Objectives for the lecture are to learn… The bones that make up the shoulder (girdle) The joints of the shoulder region The movements/kinesiology of the shoulder region The muscles of the shoulder region and their innervation The blood supply to the shoulder region Common pathology of the shoulder region

Introduction to the shoulder : 

Introduction to the shoulder Upper limb = mobile Positions the hand to accomplish its fine movements Described as a region Most flexible joint/structure in the body Flexibility = instability and injury Common cause of physician visits

What is the pectoral girdle? : 

What is the pectoral girdle? clavicle and scapula

Slide 5: 

Scapula

Slide 6: 

Clavicle(left) Superior View Inferior View

Sternoclavicular joint : 

Sternoclavicular joint

Slide 8: 

THE ONE-AND-ONLY SYNOVIAL JOINT THAT ATTACHES THE UPPER LIMB TO THE TRUNK IS THE STERNOCLAVICULAR JOINT

Sternoclavicular joint : 

Sternoclavicular joint Superficial, easy to examine the joint Stability: one of the least dislocated joints in the body

Articular fibrocartilage disc : 

Articular fibrocartilage disc

Costoclavicular ligament: very strong major stabilizing factor of the SC joint : 

Costoclavicular ligament: very strong major stabilizing factor of the SC joint

Costoclavicular ligament : 

Costoclavicular ligament FULCRUM

Slide 13: 

Kinematics about the SC joint 3 degrees of freedom

The scapula and clavicle articulate at the acromioclavicular joint : 

The scapula and clavicle articulate at the acromioclavicular joint Bones of the AC joint are not stable

Slide 15: 

AC joint with lots of tough ligaments

Slide 16: 

Interaction of the AC joint with the Scapula 3 degrees of freedom

Glenohumeral joint : 

Glenohumeral joint

Ball is much larger than the socketGolf-ball-on-a-tee relationship : 

Ball is much larger than the socketGolf-ball-on-a-tee relationship What prevents the ball and socket from dislocating?

Check reins at end-range: capsule and ligaments : 

Check reins at end-range: capsule and ligaments

Slide 21: 

Rotator cuff as it attaches onto the humerus “SITS” Greater Tubercle Supraspinatus Infraspinatus Teres Minor Lesser Tubercle Subscapularis

Slide 22: 

Periarticular tissues that support the GH joint

Slide 23: 

Tendons that support the GH joint

Glenoid labrum : 

Glenoid labrum Fibrocartilage that deepens the socket Attached to the edge of the glenoid rim Partial attachment to the long head of the biceps tendon

Slide 25: 

Kinematics about the GH joint (3 degrees of freedom)

Slide 26: 

Bursa of the Shoulder (Lateral View)

Shoulder Bursa (Anterior View)Notice the relationship of the subdeltoid and subacromial bursae to the coracoacromial arh : 

Shoulder Bursa (Anterior View)Notice the relationship of the subdeltoid and subacromial bursae to the coracoacromial arh

Slide 28: 

Schematic of the ST (Scapulothoracic Joint)

Slide 29: 

Scapulohumeral Rhythm GH joint abduction/ flexion occurs simultaneously with scapular upward rotation

For full abduction to occur: : 

For full abduction to occur: 1st 30 degrees: glenohumeral joint Then, movement occurs at the glenohumeral joint AND the pectoral girdle (upward rotation). Glenohumeral movement Scapular (pectoral girdle) movement

Movements of the Scapulothoracic Joint : 

Movements of the Scapulothoracic Joint Elevation/Depression Protraction/Retraction Rotation

Slide 32: 

Elevators Upper trapezius Levator scapulae Rhomboids

Slide 33: 

Depressors Trapezius (lower) Pec minor Subclavius Latissimus Dorsi

Slide 34: 

Protractor Serratus Anterior Pectoralis major

Slide 35: 

Retractors Middle trapezius Rhomboids Lower trapezius

Rotation (upward) : 

Rotation (upward) Upper Trapezius Lower Trapezius Serratus Anterior (These work together as a force couple)

Force couple : 

Force couple

Winged ScapulaWeakness in the Serratus Anterior : 

Winged ScapulaWeakness in the Serratus Anterior

Scapular stabilization : 

Scapular stabilization

Rotation (downward) : 

Rotation (downward) Lower pec major Pec minor Rhomboids Levator scapulae

Scapular depression : 

Scapular depression

Movement of the Glenohumeral Joint : 

Movement of the Glenohumeral Joint Flexion Extension Abduction Adduction Internal Rotation External Rotation

Slide 43: 

Flexion Anterior deltoid Coracobrachialis Biceps brachii

Slide 44: 

Flexion Anterior deltoid Coracobrachialis Biceps brachii

Slide 45: 

Extension Posterior deltoid Latissimus dorsi Teres major Long head of triceps brachii

Abduction: deltoid and supraspinatusDeltoidsupraspinatus(1) : 

Abduction: deltoid and supraspinatusDeltoidsupraspinatus(1)

Slide 47: 

Adductors Latissimus dorsi Teres major Pectoralis major

Slide 48: 

External rotators Infraspinatus Teres minor

Slide 49: 

Internal rotators Subscapularis Pectoralis Major Teres Major

Attachment sites of the anterior humerus : 

Attachment sites of the anterior humerus

Rotator cuff force couple/synergistic motion : 

Rotator cuff force couple/synergistic motion

Anterior shoulder : 

Anterior shoulder

The next layer : 

The next layer

One deeper : 

One deeper

Next layer down : 

Next layer down

You will want to know this : 

You will want to know this

Posterior view : 

Posterior view

Slide 61: 

Spaces of the posterior shoulder

Slide 62: 

Axillary artery = Blood supply to the Shoulder region 1 2 3

Slide 63: 

Axillary artery = Blood supply to the Shoulder region Collateral circulation to the scapula

Common Clinical Conditions of the Shoulder : 

Common Clinical Conditions of the Shoulder

Clavicle fractures : 

Clavicle fractures 5% of all fractures Most common pediatric fx Vast majority fall onto shoulder

Clavicle fractures : 

Clavicle fractures Approximately 80% are fractures in the middle third of the clavicle

A-C joint separation : 

A-C joint separation

Staging severity : 

Staging severity Grade 1- tearing of some AC joint ligaments Grade 2- AC joint and some trapezoid ligament Grade 3- AC and both coracoclavicular ligaments. Obvious step off deformity.

Dislocation of the GH Joint : 

Dislocation of the GH Joint Normal Anterior inferior dislocation

Rotator cuff tendinitis is common : 

Rotator cuff tendinitis is common Tendinitis is a condition in which there is tendon inflammation or degeneration It hurts when a force pulls on the tendon (i.e., muscle contraction pulls on the tendon or stretch the tendon) The pain is located at the problem site

Rotator cuff tears are common : 

Rotator cuff tears are common

Impingement Syndrome : 

Impingement Syndrome Inflammation of the rotator cuff tendons as they pass through the subacromial space. Factors that make the already tight space even tighter: Bony abnormalities (curved acromion) Muscle Weakness Rotator cuff weakness causing poor arthrokinemetics Scapular weakness causing poor stabilization Inflammation of the subacromial bursa

Slide 73: 

Mechanisms of Impingement Syndrome The roof of the coraco-acromial arch, the floor of the humeral head

Scapular/postural role in impingement : 

Scapular/postural role in impingement

Thoracic outlet syndrome : 

Thoracic outlet syndrome