Flashcards in Lecture 6.1 Deck (56):
What structures make up the pectoral girdle?
What structures is the shoulder complex between?
What are the movements that the shoulder joint can do?
Flexion (180 degrees)/Extension (about 50 degrees) (saggital plane)
Adduction (movement to midline limited by the trunk) /Abduction (280 degrees) (coronal plane)
Medial + Lateral rotation
Circumduction (complete circular motion in upper limb this is a combination of all 3 movements).
What are the 3 bi-articular joints of the shoulder complex?
What are the physiological (functional joints of the shoulder)?
Subdeltoid (deep to the deltoid muscle)
Scapulothoracic (allows a larger range of motion for abduction)
What are the ligaments of the sternoclavicular joint?
Anterior + Posterior Sternoclavicular
Interclavicular (between the clavicles)
These are intrinsic ligaments of the sternoclavicular joint.
Costoclavicular (extrinsic ligament that stabilizes the joint)
What kind of joint is the sternoclavicular joint?
Saddle joint. Contains an articular disk which divides the joint into 2 separate articular cavities. this makes it a complex joint.
What are the movements that can take place at the Sternoclavicular joint and what is the purpose of these motions?
allows scapula to elevate and depress and allows the scapula to protract and retract when the clavicle is abducted and adducted.
This joint can also rotate.
What arteries supply the sternoclavicular joint?
Dislocation very rare at sternoclavicular joint. Blood supply is from the subclavian artery (internal thoracic and suprascapular arteries form anastomoses)
What nerve goes to the sternoclavicular joint?
nerve to subclavius is the nerve to the sternoclavicular joint.
How is an anterior sternoclavicular subluxation treated?
Anterior sternoclavicular subluxation can be fixed conservatively by immobilizing the joint.
What structures are endangered in a posterior sternoclavicular subluxation?
Subclavian and Carotid arteries.
What type of joint is the acromioclavicular joint?
A synovial plane joint between acromion process of scapula and the clavicle.
Does the acromioclavicular joint contain an articular disk?
Yes a partial articular disk to allow separate movements to take place.
What is the main intrinsic ligament of the acromioclavicular joint?
What is the most important ligament of the acromioclavicular joint?
Most important ligament of acromioclavicular joint is the 2 parted coracoclavicular ligament. This is an extrinsic ligament
These parts are:
(narrow at its attachment to the coracoid process and wide at the acromion process)
Trapezoid (lateral to the conoid ligament)
What is the function of the parts of the coracoclavicular ligament?
The coracoclavicular ligaments work at right angles to each other. conoid ligament stops superior displacement of clavicle. Trapezoid ligament stops excessive rotation of the clavicle against the scapula.
What is a common injury to the acromioclavicular ligament?
Shoulder separation arises from contact sports most commonly.
What is the Acromioclavicular joint's blood supply?
Suprascapular artery (from subclavian artery)
Thoracoacromial artery (second part of the axillary artery)
What is the acromioclavicular joint's nerve supply?
Lateral pectoral nerve
(lateral and posterior cord of the brachial plexus)
What are actions that occur at the acromioclavicular joint?
scapula elevation and depression
Scapula retraction and protraction
What is the attachment, function, and action of the serratus anterior muscle?
Serratus anterior attaches to the medial border of the scapula and is innervated by the long thoracic nerve. Action is protraction of the scapula.
What muscles facilitate protraction of the scapula?
What muscles are responsible for retraction of the scapula?
How does the elevation of the glenoid fossa take place?
For elevation of the glenoid cavity to take place 2 muscles work together; superior fibers of trapezius pull scapula upwards and the serratus anterior muscle fibers pull the glenoid upwards.
This causes the rotation of the scapula.
Elevation is facilitated by levator scapulae and trapezius' superior fibers.
How are the sternoclavicular and acromioclavicular joints related?
Both acromioclavicular joint and sternoclavicular joint move when there is movement of the clavicle.
How many grades of shoulder separation are there?
What happens in a grade 1 shoulder separation injury?
A-C ligaments stretched but not torn while coracoclavicular ligaments are not damaged.
What happens in a grade 2 shoulder separation injury?
A-C ligaments are torn but coracoclavicular ligaments are still intact.
What happens ina grade 3 shoulder separation?
A-C ligaments are torn and so are coracoclavicular ligaments.
What results from a grade 2 and 3 shoulder separation and what vessels are at risk from this?
Sagging shoulder results from grade 2 and 3 shoulder injury. The most damaged nerve from this is the axillary nerve. The posterior and anterior humeral circumflex arteries are in danger as well. The musculocutaneous nerve is also affected.
What is the labrum of the glenohumeral joint called?
Glenoid labrum (fibrocartilaginous rim is painless and increases range of movement that can take place)
What tendon is found in the glenohumeral capsule?
The long head of the biceps tendon.
What is the blood supply of the glenohumeral joint?
Circumflex humeral arteries.
What is the nerve supply of the glenohumeral joint?
What are the intrinsic ligaments of the glenohumeral joint?
Superiorly the coracohumeral ligament (forms a roof to prevent superior dislocation)
Glenohumeral ligaments anteriorly and inferiorly.
*These ligaments are hard to differentiate but are differentiated by thinnings that can create potential spaces.
What is the function of the inferior part of the glenohumeral ligament?
Inferior part of glenohumeral ligament is a little lax to allow the humerus to sit in this inferior part of the ligament.
What is the position of maximal stability of the glenohumeral joint?
Abducted externally rotated and extended
What are the extrinsic ligaments of the glenohumeral joint?
Transverse humeral ligament
What is the function of the rotator cuff muscles?
Rotator cuff muscles act as dynamic ligaments of "fixators"
What are the 3 deficiencies of the glenohumeral joint's articular capsule?
anterior glenohumeral ligament has a deficiency which allows synovial fluid to contact the subscapular bursa.
Long head of the biceps goes through another deficiency in the articular capsule.
What bursae can be found near the glenohumeral joint?
Where is the subacromial bursa located?
Subacromial bursa is superficial to the supraspinatus tendon and deep to the coracoacromial ligament.
What is the position that most commonly is dislocated?
The position of greatest stability of the shoulder is also the position where dislocation is most common.
What do flexor musculature do at the shoulder joint?
Produce flexion, adduction, and medial rotation.
What do extensor musculature do at the shoulder joint?
Extension, abduction, and lateral rotation.
What is the most clinically important action of the shouder joint?
What is the subdeltoid physiological joint between?
Subdeltoid joint is between supraspinatous and glenohumeral joint.
What are some conditions associated with the subdeltoid joint?
calcification of supraspinatus can cause painful arc syndrome.
What bursa is found between the supraspinatus and the GH joint?
How does abduction of the shoulder joint take place?
First 15 degrees of abduction is done by the supraspinatus. This is followed by the deltoid muscle.
Where does supraspinatus insert?
supraspinatus inserts at the greater tubercle.
What causes subacromial bursa?
Subacromial bursa can get inflamed from repetitive motion.
What is the most common direction of dislocation of the glenohumeral joint?
Typical position of dislocation of the glenohumeral joint is anterior and inferior.
What are the typical situations that lead to posterior shoulder dislocation?
Posterior dislocation of the shoulder joint occurs when adducted and internally rotated from electric shock or a seizure.