Shoulder

• Mobility – the shoulder motion (combined withthe elbow) allows for infinite possibilities of hand positioning in space
• Stability – the shoulder must be stabilized tomaximize hand function

• Sternum & ribs
• Clavicle
• Scapula
• Humerus

• steroclavicular
• acromioclavicular
• glenohumeral
• scapulothoracic (not a true joint)

Sternum

• Manubruim - clavicular facets and costals facets
• body - rib attachment
• xiphoid process
• sternal (jugular) notch
• sternal angle - used to count the ribs starting with the second

The clavicle links the axial skeleton to appendicular skeleton

The clavicle is s-shaped. It anterior surface is convex medially and concave laterally. When the bone breaks, it fractures at the part between both ends

• angled 20 degrees posterior to frontal plane
• angled 10 degrees superior to horizontal plane (medial to lateral)

• Bony shape - thin, triangular bone
• 3 angles - inferior, superior medial, and lateral
• 3 borders - medial, superior, and lateral
• invested in muscle
• structures - scapular spine, acromion, glenoid fossa, and coracoid

• The spine divides posterior scapular surface into supraspinous fossa and Infraspinous fossa
• Muscles attached here are Deltoid and Trapezius

the acromion is the lateral end of the scapular spine and articulates with the clavicle at the clavicular facet

the deltoid and the lower/middle fibers of trapezius

coracoacromial ligament

pear shaped concavity for the humerus and it articulates with the humeral head

only 25% surface area of the humeral head

• composition - dense fibrous tissue
• function - deepens glenoid from 2.5mm to 5mm
• long head of biceps brachia attaches on the superior aspect

• glenoid tilt - 4 degrees upward tilt (range - 7 degrees downward tilt; 16 degrees upward tilt)
• plane of the scapula - angled at 35 degrees from frontal plane (lateral edge is more anterior than medial edge)

coracoid process

• Coracoacromial
• Coracohumeral
• Coracoclavicular

• Pectoralis minor
• Short head biceps
• Corcobrachalis

• Necks - anatomic and surgical
• tuberosities - greater [subscapularis] & lesser [teres minor, infraspinatus, supraspinatus]
• bicipital groove - pectorals major, teres major, and latissimius dorsi
• deltoid tuberosity - deltoid
• radial groove

130° - 150° (normal)

30° - 50° retroverted (does itlook anterior or posterior – so the humeral looks back about 30-50 degreescompared to the epicodyles)

AC joint & SC joint

• Elevation – depression of scapula
• Protraction-retraction of scapula
• Upward-downward rotation of scapula - coupling must occur in order to complete this action [AC joint] [inferior angle]
• Anterior-posterior tilting of scapula (based on the top of the scapula) – again coupling must occur in order to complete this action [AC joint]
• Internal-external rotation of scapula [medial and lateral rotation] [based on glenoid cavity) – coupling must occur in order to complete this action

Axial attachment – most proximal joint links shoulder complex to axial skeleton

saddle

• Fibrocartilage
• Joint congruity improves fit
• Shock absorption

• Sternoclavicular ligaments intrinsic ligament; reinforces the capsule {anterior and posterior}
• Costoclavicular ligaments - 1. First rib to clavicle 2. Major SC stabilizer 3. Limits all motions but depression
• Interclavicular ligament limits depression

• Three - elevation/depression, protraction/retraction & axial rotation of clavicle

• Plane & axis frontal plan; anterior/posterior axis
• Available ranges 45 degree elevation, 10 degree depression [what position is start position in normal posture? – 10 degrees]

• Elevation - clavicle rolls superior; clavicle glides inferior
• depression - clavicle rolls inferior; clavicle glides superior

• Plane & axis horizontal plane; axis
• Available ranges 15-30 degrees each direction

• retraction - clavicle rolls superior; glides superior
• protraction - clavicle rolls inferior; glides inferior

• Plane sagittal plane; medial/ laterial axis
• Ranges superior aspect of clavicle rotates posterior 40-50 degrees with should elevation

spin of clavicle on sternum [no roll and glide – SPIN]

plane joint

• Lateral end of clavicle
• Clavicular facet on acromion

• Acromioclavicular {intrinsic}- Superior and Inferior
• Coracoclavicular [ice hockey] - Trapezoid & Conoid

• Upward/downward rotation of scapula
• Anterior/posterior tipping of scapula
• Medial/lateral rotation of scapula

• No bone-bone contact - NOT A TRUE JOINT
• Anterior surface of scapula
• Posterior thoracic wall

• Between ribs 2 &7
• Medial border 6cm from thoracic spinous processes
• Scapular plane: 35 degrees anterior to frontal plane

• Articular surfaces - Sternal end & Acromial end
• Costal tuberosity - attachment of costocalvicular ligament
• Conoid tubercle - attachment of coraclavicular ligament

it varies!