The Shoulder and RTC chapter 6

The Shoulder Joint

-Also called the Glenohumeral Joint: an articulation of he glenoid fossa of the scapula with humeral head. -allows more motion than any other joint -is the least stable -supported by skeletal muscles, tendons, ligaments -ball-and-socket disrthosis -natural position is called scaption: 30 degrees anterior to the frontal plane.

anterior shoulder dislocation

-Hill Sachs Lesion: Glenoid has hard ridge and when shoulder dislocated anteriorly and then drops inferiorly its the soft hyaline cartilage on the head of the humerus that impinged up against the hard ridge of the glenoid and starts to create a dent in it. -dislocation can cause damage to nerves of brachial plexus; Median Nerve: tingling in anterior portion of wrist and forearm; Radial- posterior arm; Axillary- diminished deltoid function.

SLAP lesions

-SLAP ( superior Labrum ant-post) when the ligament that deeps the socket of the glenoid (glenoid labrum) becomes torn usually as a result of FOOSH (fall on out stretched hand shoulder generally in flexion) -graded by clock positions

clavicular ligaments

-acromioclavicular ligament: hold the acromion process to the clavicle and prevents posterior dislocation of the clavicle ( affects AC joint) -coracoclavicular ligament 2: not directly located at the acromioclavicular joint; help keep AC joint in place 1. trapezoid portion: lateral 2. Conoid portion- medial

clavicle

-acts a s strut connecting upper extremity to thorax; has connection with sternum -protects brachial plexus and vascular structures -serves as attachment site for many shoulder muscles

shoulder joint structure anatomy

-bone: scapula, clavical, humerus -connective tissue --glenoid labrum: cartilaginous ring, surrounds glenoid fossa ---increases contact area between head of humerus and glenoid fossa. ---increases joint stability -glenohumeral ligaments: reinforce that glenohumeral joint capsule --superior, middle, inferior (anterior side of joint) -coracohumeral ligament (superior)

GHJ bones and articulation

-bones: humerus, scapula, and clavicle (S+C=shoulder girdle). -articulation: glenohumeral joint

coracoacromial ligament

-connects coracoid process to acromial process -roof over head of humerus (superior stabilization) , serves as a protective arch (RTC, biceps tendon, bursa) *does not attach to the clavicle *when you do arthroscopy and release the ligament you have not interfered with the stability of the clavicle and the AC joint; removal=loss of superior stabilization.

landmarks of the clavicle

-costal tuberosity: one of the ribs comes across here -conoid tubercle: bumps; ligaments insert there. -sternal facet: medial end of clavical; saddle shaped because it is a saddle joint.

Glenoid Labrum

-deepens socket of glenoid cavity -fibrous cartilage lining (ring shaped) -extends past the bone to give more contact and stability to shoulder joint.

AC separation

-downward force on acromion usually a fall without FOOSH. -Grade 1: some of the fibers have been strained -Grade 2: some structural damage to fibers Grade 3: all fibers have been transected -piano key

clavicular fracture

-downward force on clavicle usually a fall with or without FOOSH -lump

abduction at glenohumeral joint: the kenetic arc

-force couple -muscles pulling in different directions to accomplish the same motion -upper trapezius pulls up -lower trapezius pulls down -lower serratus pulls out anterior -net effect is upward rotation

muscular considerations

-force-length relationships quire variable due to multiple joints -tension development in agonist frequently requires tension development in antagonist to prevent dislocation of the humeral head -force couple- 2 forces equal in magnitude but opposite in direction.

clinical picture of dislocated shoulder

-loss of contour of the shoulder, may appear as a step -anterior bulge of head of humerus may be visible or palpable -a gap can be palpated above the dislocated head of humerus -caused by FOOSH injury shoulder abducted and extended

scapulothoracic joint

-no osseous connection -SUBSCAP & SA: slide and glide over rib cage; has to happen for motion to occur

stability functions of shoulder girdle

-provides stable bade from which shoulder muscles can generate force --shoulder girdle muscles act as stabilizers --maintain appropriate force-length relationships with prim. movers of GHJt. --maintain maximum congruence of shoulder joint: keep head of glenoid tracking head of humerus though differ motions

glenohumeral ligamentS

-reinforces anterior portion of the capsule - not well defined all blend together -anterior ligaments -3 ligaments: superior glenohumeral ligament; middle glenohumeral ligament; inferior glenohumeral ligament -actually pleated folds of the capsule -most commonly disrupted in shoulder dislocation -95% of shoulder dislocations happen anteriorly.

glenohumeral joint movements and planes

-sagittal plane, frontal axis: flexion, extension, and hyperextension. -frontal plane, sagittal axis: abduction and adduction -transverse plane, vertical axis: external rotation, internal rotation, horizontal abduction, and horizontal adduction

movements in the frontal plane GH joint- Abduction

-shoulder girdle-UR totals: upward rotation- 60

shoulder complex

-shoulder girdle: scapula and clavicle -shoulder joint: scapula and humerus -sternoclavicular joint -acromioclavicular joint -glenohumeral joint: ball and socket joint that relays on interplay of the shoulder complex area to allow it to move. -scapulothoracic articulation: where the scapula rotates around the rib cage (4)

shoulder Burasae

-subacromial: most easily impinged -subcoracoid -subscapular -subdeltoid

Parts of scapula

-subscapular fossa: where subscapularis comes off of -coracoid process: where pec minor attaches -lateral border: AKA axial border of scapula -glenoid fossa: most movable but least stable because this large ball is sitting in this tiny cup; some structures help deepen that ( glenoid labrum)

shoulder girdle

-term used to discuss activities of the scapula, clavicle, and sternum. -the sternoclavicular SC and acromioclavicular AC joints allow shoulder girdle motions (scapulothoracic articulation): --elevation and depression --protection and retraction --upward and downward rotation -five muscles attach to the scapula and or clavicle and provide shoulder girdle movement. --posterior: trapezius, levator scapulae, and rhomboid muscles. --anterior: serratus anterior and pectoralis minor.

acromioclavicular joint

-very weak: coracoclavicular ( trapezoid and conoid) are what is mostly holding it together. motions: -horizontal plane: adjustments during scapulothoracic elevation -sagittal plane: adjustment during.

adhesive capsulitis

AKA frozen shoulder: GH capsule is stuck shut; requires a lot of stretching and is usually uncomfortable for pt.

coracohumeral ligament

Attachments -lateral side of coracoid process -medial side of greater tubercle -strengthens the upper part of the joint capsule

coroc-acromial ligament

can cause impingement on coracoid process and acromion *arthroscopy for shoulder impingement they will shave off the under surface of the acromion and release the corocacromial ligament so we have more room for passage of things under the shoulder. -acromion (clavicle) and coracoid process (scapula) -project laterally, superior to the humerus -help stabilize the joint.

shoulder girdle muscles; movement of scapula

retraction: adduction reduced lateral tilt rhomboids trapezius levator scapulae protraction: abduction lateral tilt serratus anterior pectoralis minor *linear movement in the frontal plane; angular movement in the transverse plane. elevation: rhomboids trapezius levator scapulae; linear movement in the frontal plane. depression: lower trap lat dorsi pec major subclavius downward rotation: rhomboids pec minor levaor scap upward rotation: serratus upper trap lower trap

shoulder ligaments

stabilize shoulder joint name tells location -coracohumeral -glenohumeral -coraco-acromial -coracoclavicular -acromioclavicular *shoulder separation: acromioclabivuar joint ( involving clavicular) *shoulder dislocation: glenohumeral joint ( involving glenohumeral ligaments)

Sternoclavicular joint

very strong between the sternum and clavicle contains: - strong costoclaivicular ligament -articular disk: articulates with sternal end of clavicle; medial end of clavicle is convex shape while the clavicular facet is reciprocally shaped. motions: -frontal plane: post. rotation -Sagittal plane: post. rotation -horizontal plane: protraction, retraction