Lecture Shoulder part 2 Deep Shoulder Flashcards
What are the joints of the shoulder?
- sternocalvicular joint
- gleno-humeral joint
- acromioclavicular joint
Where does clavicle articulate anteriorly?
- at manubrium of sternum with sternoclavicular joint
Where does clavicle articulate laterally?
- acromioclavicular joint
What articulates at gleno-humeral joint?
- glenoid of scapula and head of humerus
What is the pectoral girdle?
- clavicle and scapula
What type of joint is the sternoclavicular joint?
- synovial joint
What is the only true boney articulation between upper limb and thorax?
- sternoclavicular joint
Can the sternoclavicular joint move in multiple planes?
- Yes it is a multiaxial joint
-
What movements does the sternoclavicular joint have?
- elevation/depression (clavicle and disc) - protraction/retraction (clavicle and sternum) - rotation (both)
Does dislocation of the sternoclavicular joint occur frequently?
- no the clavicle is more likely to fracture from force first
What is the movement of plane joints?
- they slide on each other
How does acromioclavicular joint dislocate?
- upward force stretches or tears the ligaments in some way
What is a grade 1 separated shoulder?
- acromioclavicular ligament sprain
What is a grade 2 separated shoulder?
- acromioclavicular ligament tear
What is a grade 3 separated shoulder?
- acromioclavicular and coracoclavicular ligaments are torn
What type of joint is the genlohumeral?
- synovial capsule
Is the glenohumeral joint strong?
- no it is weak but very mobile
What reinforces the glenohumeral joint?
- tendons of the rotator cuff muscles
Long tendon of pierces the capsule and attaches to supraglenoid tubercle of scapula and glenoid labrum
-bicheps brachii
What forms roof of glenoid fossa and attaches coracoid process to acromion?
- coraco acromial ligament
What forms roof of glenoid fossa?
- coraco acromial ligament
What are bursa?
- pillows of synovial fluid
Dislocation of glenohumeral joint is?
- dislocation of shoulder
Dislocation of acromioclavicular joint is?
- separated shoulder
what is the most common dislocation direction?
- downward (inferior) direction but described as anterior
What prevents upward dislocation?
- the coracoacrominal structures and rotator cuff
_____ dislocations are more rare
- posterior
Who do anterior dislocations occur most commonly in?
- young adults, especially athletes
How do the dislocations happen?
- hyperextension with lateral rotation
- humeral head is forced in infero-anterior direction
- fibrous layer of joint capsule and glenoid labrum may tear
What nerve do we worry about with shoulder dislocation?
- axillary nerve
What muscles does the axillary nerve supply?
- deltoid
- teres minor
- triceps brachii (radial nerve more common)
Axillary nerve supplies sensory from:
- shoulder joint
- skin covering the inferior deltoid
What is frozen shoulder?
- adhesive capsulitis
What is adhesive capsulitis?
- chronic inflammation in the glenohumeral joint can lead to fibrosis between joint capsule, rotator cuff muscles and synovial bursa
What range of motion does frozen shoulder affect?
- abduction affected, compensatory scapular movements
Who is frozen shoulder common in?
- individuals 40-60 years of age
______ can be initiated by glenohumeral dislocation, supraspinus tendinitis, bicipital tendinitis and or rotator cuff tears
- adhesive capsulitis
How do you treat adhesive capsulitis?
- interscalene block to numb nerves of shoulder
- manual maniupulation to break apart adhesion to allow normal range of motion
The deltoid can perform all actions except?
- adduction
What are the rotator cuff muslces?
- subscapularis
- supraspinatus
- infraspinatus
- teres minor
where does the deltoid attach proximally?
- lateral 1/3 of clavicle, acromion and spine of scapula
Where is the distal attachment of the deltoid?
- deltoid tubersoity of humerus
what nerve innervates the deltoid?
- axillary nerve (C5, C6)
What are the actions of the deltoid?
- flexes
- medially rotates
- abducts
- extends
- and laterally rotates humerus
What cord does the axillary nerve come from?
- posterior cord of brachial plexus
Where does the teres major attach proximally?
- posterior surface of inferior angle of scapula
Where is the distal attachment of the teres major?
- medial lip of intertubercular (bicipital) grooce of humerus
What are the actions of teres major?
- adducts and medially rotates humerus
What innervates the teres major?
- lower subscapular nerve (C5 and C6)
Where do the supra spinatus teres minor and infra spinatus converge?
- greater tubercle
What rotator cuff muscle attaches to the lesser tubercle of humerus?
- subscapularis
what is the action of the supraspinatus muscle?
- initiates abduction of humerus then deltoid takes over at 25-30 degrees
Where is the insertion of the supraspinatus?
- superior facet of the greater tubercle of humerus
What innervates the supraspinatus?
- suprascapular nerve
Where is the origin of the infraspinatus?
- infraspinatus fossa of scapula
Where is the insertion of infraspinatus?
- middle facet of greater tubercle of humerus
where is the origin of the supraspinatus?
- supraspinous fossa of scapula
what innervates the infraspinatus?
- suprascapular nerve
What muscle has the same function as the infraspinatus?
- teres minor
Where is the proximal attachment of the teres minor?
- middle part of lateral border of scapula
Where is the distal attachment of the teres minor?
- inferior facet of greater tubercle of humerus
What is the action of the teres minor?
- laterally rotates humerus, helps hold humeral head in place
What inervates the teres minor?
- axillary nerve
What nerve innervates the subscapularis muscle?
- upper and lower subscapular nerves
What is the action of the subscapularis muscle?
- adducts the humerus
Where is the distal attachment of the subscapularis?
- lesser tubercle of humerus
Where is the proximal attachment of the subscapularis?
- anterior surface of scapula (subscapular fossa)`
