Shoulder Joint (SCTC)

Glenoid Labrum

- glenoid fossa of scapula 'socket' & head of humerus 'ball'. - Fibro-cartilaginous rubbery structure encircles glenoid cavity, deepening socket & providing static stability to glenohumeral joint. - Cartilage.

shoulder muscles separated into 3 groups

1. Superficial muscles (Extrinsic) 2. Deep muscles (Intrinsic) 3. Muscles of the shoulder & arm

Supraspinatus Infraspinatus teres minor Subscapularis - Connect scapula to humerus. - Provide support for glenohumeral joint.

4 rotator muscles The most important shoulder muscles

Nerve problems around shoulder are rare, but the nerves most commonly affected.

Axillary Nerve Long Thoracic Nerve Suprascapular Nerve Musculocutaneous Nerve

Most shoulder motion occurs at____ For full ROM ____ must function normally

Ball & socket joint, GH joint. Ball & socket articulation. AC joint.

Injury between 3 & 6 o'clock. Associated w/shoulder dislocation (Most common).

Bankart tear

3 Arm & Shoulder Muscles

Biceps Triceps Coracobrachialis

- enter into shoulder. - Separated into anterior (flexor) & posterior (extensor) compartments.

Biceps Brachii Triceps Brachii Coracobrachialis

Long bone & most breaks occur in middle 1/3, 80%. Fx caused by direct blow, fall or car crash. Babies during birth canal.

Clavicle

Glenohumeral: - Strenoclaviclar SC - Acromioclaviclar AC - Scapulothoracic

Joints that make up glenohumeral joint

Cause pain, instability or both. Classified on location.

Labrum Tears

4 Superficial Muscles

Pectoralis Major Trapezius Latissimus Dorsi Large Deltoid

Posterior tear of the___ is ___ or reverse bankart lesion.

Posterior labrum, Posterior labral tear. Between 6 & 9 o'clock (?)

10 Deep Muscles

Rotator Cuff/ SITS: Surprasinatus Intraprasinatus Teres Minor Subscapularis Teres Major Pectoralis Minor Subclavius Rhomboids Serratus Levator Scapulae

Superior labral injury, (Superior labral anteroposterior). Associated w/bicep tendons issues. NEVER inferior, ALWAYS superior.

SLAP tear

neck of humerus

The neck lies between the head & the greater & lesser tubercles.

brachial neuritis /or Parsonage-Turners Syndrome

Uncommon disease where Brachial Plexus nerves are weakened, causing muscle wasting & weakness of shoulder.

Where clavicle meets acromion of scapula.

acromioclavicular (AC) joint

Supplies the Deltoid muscle. Most commonly stretched w/ shoulder dislocations.

axillary nerve

2 heads: Long & Short Head. - Long, intertubercular sulcus, humerus. (held in position by THL) - Short, coracoid process scapula. - radial tuberosity forearm & into fascia on medial forearm. (primarily as a tendon) - Primary flexor forearm. supinates forearm. weakly flexes arm at shoulder.

biceps brachii, arm & shoulder

Biceps muscle has 2 tendons at shoulder: The Long Head The Short Head.

biceps tendons

- Made of large # of nerves, supply arm w/ability to function & feel. - All nerves that travel down arm pass throu axilla, before dividing into individual nerves. - Carry signals from brain to muscles that move arm & carry signals back to brain about sensations (touch, pain & temp).

brachial plexus

Inflammation & swelling of subacromial bursa. Associated w/Subacromial Impingement of Shoulder

bursitis /or Subacromial Impingement of Shoulder

Bony attachment between trunk & upper limb. Articulates at 1 end w/sternum & w/acromion of scapula. 1 of 3 bones in shoulder.

clavicle

Labrum is described like a clock face: 12 o'clock superior 3 o'clock anterior 6 o'clock inferior 9 o'clock posterior. At front for either shoulder, 3 o'clock.

clock face

Ligament links coracoid to acromion. Can thicken & cause Impingement Syndrome

coraco-acromial ligament (CAL)

- 2 ligaments (trapezoid & conoid) attach coracoid process of scapula & clavicle. - Tiny ligaments (w/acomioclavicular joint) keep scapula attached to clavicle & shoulder 'square'. - Carry massive load & extremely strong. - A fall on shoulder can rupture these ligaments w/dislocation of AC Joint.

coraco-clavicular ligament (CCL)

- tip of coracoid process,scapula. (w/SHbicep) - middle 1/3, medial surface & border of humerus. - Weakly adducts arm. aids in stabilizing humerus.

coracobrachialis, arm & shoulder

Attachment point of ligaments & muscles.

coracoid process

A ball & socket articulation between head of humerus & glenoid cavity of scapula. Most movement occurs, major joint. 4 joints make this joint.

glenohumeral joint (shoulder joint)

A joint capsule, watertight sac that surrounds joint & formed by group of ligaments that connect humerus to glenoid. Group of ligaments: Superior Middle Inferior

glenohumeral ligaments (GHL)

Articulates w/the head of humerus.

glenoid cavity

- Shoulder joint is 'ball & socket' joint, the 'socket' is shallow & small, covering only 1/3 of 'ball'. - The socket is deepened by the ___ - Acts & looks like a washer, sealing 2 sides of joint together.

glenoid labrum

The head projects into the glenoid cavity.

head of humerus

Consists of the head, neck, greater & lesser tubercles & the shaft.

humerus

- infraspinous fossa of scapula. (Tendon of infraspinatus passes posteriorly on to glenohumeral joint) - middle facet greater tuberosity humerus & capsule of shoulder joint. - draws humerus towards glenoid fossa, resisting posterior dislocation of arm. laterally rotates & abducts arm.

infraspinatus, deep (Rotator Cuff)

- Main source of ____ for shoulder. - Ligaments help hold shoulder in place & keep it from dislocating. Glenohumeral ligaments: Superior Middle Inferior

joint stability

An injury to shoulder w/shear forces either in anterior, posterior or superior directions leads to___.

labral tear (in affected area)

Contour of shoulder, largest & strongest muscle of shoulder. Lifting arm, once arm is away from side. 3 portions: anterior, middle & posterior. - Anterior, anterior & superior of clavicle. Middle, acromion process scapula. Posterior, posterior spine crest scapula. - deltoid tuberosity on humerus shaft. - Anterior, flexes & rotates arm medially. - Middle, abducts arm. - Posterior, extends & rotates arm laterally.

large deltoid, superficial (lateral)

- Vertebrae, hip & ribs: spinous process lower 6 thoracic vertebrae, lumbar vertebrae, sacral vertebrae, iliac crest of hip bone & lower 3/4 ribs. - bottom intertubercular groove, humerus. - Extends, adducts & medially rotates arm. draws shoulder downward & backward. keeps inferior angle, scapula against chest wall.

latissimus dorsi, superficial (posterior)

- transverse processes, CERVICAL VERTEBRAE. - superior & medial corner of scapula. - Elevates scapula.

levator scapulae, deep (posterior)

- Very important tendon, travels throu glenohumeral joint. - Begins glenoid, across front shoulder & connect to biceps muscle. - A common source of shoulder pain & can rupture.

long head biceps tendon (LHB)

Supplies serratus anterior muscle & can cause winging of shoulder (scapula)

long thoracic nerve

Either connect scapula & clavicle to trunk OR Connect clavicle, scapula & body wall to proximal (top, towards body) end humerus.

muscles of shoulder

Supplies Biceps muscle & can rarely be injured at surgery

musculocutaneous nerve

Connect to the proximal end of humerus & anchor it to body.

pectoralis major pectoralis minor latissimus dorsi teres major deltoid

Provides movement & support in front of shoulder. 2 heads: Clavicular head & Sternocostal head. - Clavicular, midline half clavicle. - Sternocostal, manubrium & sternum. - Lateral lip intertubercular sulcus, humerus. - 2 heads act together, flex, adduct & medially rotate arm at GH joint.

pectoralis major, superficial (anterior)

Small, lies deep to pectoralis major & passes as 3 muscular slips from - thoracic wall (ribs III to V). - coracoid process, scapula. - Draws scapula forward & downward. raises ribs in forced inspiration.

pectoralis minor, deep (anterior)

- vertebral column - medial border, scapula. (slightly below levator scapulae). - Retract & elevate scapula.

rhomboid major & minor, deep (posterior)

- Group of 4 tendons that connect deepest layer of muscles to humerus. Tendons of rotator cuff muscles: Supraspinatus Infraspinatus Teres Minor Subscapularis

rotator cuff tendons, SITS

3 processes: acromion, spine, coracoid process. - Forms back portion of shoulder girdle. - Flat blade glides along back of chest allowing extended movement of arm.

scapula

Where scapula meets w/ ribs at the back of chest.

scapulothoracic joint

- superior borders 1st 8/9 ribs & fascia covering intercostal spaces. - medial border of scapula. - Pulls scapula forward of thoracic wall. rotates scapula for abduction & flexion of arm.

serratus anterior, deep (lateral)

- Greatest range of motion of any joint. Most flexible joint. - Activity of numerous muscels working together. - Made up of 4 joints & 5 linked bone groups related & work together.

shoulder joint

Where the clavicle meets sternum.

sternoclavicular (SC) joint

- Sac between 2 moving surfaces, contains small amount of lubricating fluid. - Between rotator cuff muscles & outer layer of large bulky muscles. - Everywhere in body, wherever 2 body parts move against 1 another & no joint to reduce friction.

subacromial bursa

Small, lies deep to pectoralis major. - rib I & its costal cartilage. - inferior surface of clavicle. - Depresses clavicle. draws shoulder forward & downward. steadies clavicle during movements.

subclavius, deep (anterior)

- Anatomical variants, where labrum can be 'lifted up' between 12 & 3 o'clock. - Not to be confused w/ labral tear, its edge is round & smooth, not red & ragged.

sublabral foramen

Forms largest component of posterior wall of axilla (directly under joint where arm connects to shoulder). - subcapular fossa, anterior surface of scapula. - lesser tuberosity of humerus & part of capsule shoulder joint. - Medially rotates arm. stabilizes glenohumeral joint

subscapularis, deep (Rotator Cuff)

Supplies supraspinatus & infraspinatus muscles, can be entrapped or diseased

suprascapular nerve

- The rotator cuff tendons attach to the deep rotator cuff muscles. - These 4 muscles are involved in raising arm from side & rotating shoulder in many directions. - The rotator cuff mechanism also helps keep shoulder joint stable by holding humeral head in glenoid socket.

supraspinatus infraspinatus teres minor subscapularis SITS

- The muscle that lifts arm out to the side & very important for daily movement. - Most commonly affected by overuse & trauma. - Injury leads to Rotator Cuff Tear & overuse Subacromial Impingement.

supraspinatus tendon

- supraspinatus fossa of scapula. (Passes as tendon under acromion, separated from bone by subacromial bursa, over GH joint) - superior facet of greater tubercle. - Weakly flexes arm. aids deltoid in abduction of arm. draws humerus toward glenoid fossa. prevents deltoid from forcing humerus up against acromion.

supraspinatus, deep (Rotator Cuff)

Extensions of muscles, attach muscles to bone. Muscles move bones by pulling on tendons.

tendons

- posterior surface, inferior angle of scapula. - medial lip of intertubercular sulcus, humerus. (Lies anterior) - Extends & medially rotates humerus.

teres major, deep (posterior)

- posterior axillary boarder of scapula. - capsule of shoulder joint & lower facet of greater tuberosity of humerus. - Laterally rotates arm. weakly adducts arm.

teres minor, deep (Rotator Cuff)

Prominent landmarks on humerus. Attachment sites for the rotator cuff muscles.

the greater & the lesser tubercles

Holds tendon of long head biceps muscle in groove between greater & lesser tubercle on humerus (intertubercular sulcus groove).

transverse humeral ligament (THL)

Originates base of the skull and/or spine, Connect scapula & clavicle to the trunk of body.

trapezius levator scapulae rhomboid

- Back of skull & most vertebrae of spine. - clavicle, scapula spine & acromion. - Powerful elevator of shoulder. & rotates scapula to extend the reach upwards.

trapezius, superficial (posterior)

3 heads: Long, Lateral, Medial. - Long, infraglenoid tubercle, scapula. Lateral, upper half humerus shaft. Medial, lower half of humerus shaft. - olecranon of ulna. - Primary extensor of forearm at elbow joint. Extend & adduct humerus.

triceps brachii, arm & shoulder