anatomy of the shoulder Flashcards
which ligaments stabilize the pectoral gurdle?
- corococlavicular
- acromioclavicular
- glenohumeral- superior, middle and inferior
what does the coracoacromial ligament do?
forms an arch whcih supports the head of the humerus
also prevents superior disclocation
what movements can you have at glenohumeral joint?
- adduction and abduction
- flexion and extention
- lateral and medial rotation
- circumduction
what is the action preformed by the deltoid?
- abduction of arm
Posterior fibres:
- Extension + lateral rotation
Anterior fibres:
- Flexion + medial rotation
what are the origins and insertions of deltoid?
Origin: Spine of scapula + acromion + clavicle
Insert: Deltoid tuberosity
what muscles are important for abduction of the arm?
- deltoid
- latissimus dorsi
- pectoralis major
how is the glenohumeral joint aften disslocated?
anterior dislocation
what 5 factors increase the stability of the glenohumeral joint?
- coracoacromial arch
- , glenohumeral ligaments
- deepening of glenoid fossa by glenoid labrum
- long head of biceps above and triceps below
- tendons of the rotator cuff muscles
what does the coracoacromial ligament prevent?
superior dislocation
what do the glenohumeral ligaments prevent?
superior medial and inferor glenoid ligaments support the anterior of the joint
what is the function of thr glenoid labrum?
deepens the glenoid fossa for articulation
how is the glenohumeral joint splinted?
- origin of the long head of the biceps is supraglenoid tubercle
- origin of the long head of triceps is the infraglenoid tubercle
- both together splint the joint
which 4 muscles fuse with the joint capsule to make the rotator cuff muscles?
- supraspinatous
- infraspinatous
- teres minor
and subscapularis
which rotator cuff muscles are posterior?
- supraspinatous
- infraspinatous
- teres minor
which rotator cuff mucles are anterior?
subscapularis
what are the functions of the rotator cuff muscles?
supraspinatous-initiate abduction
infraspinatous- lateral rotation
teres minor- lateral rotation
subscapularis- medial roation
what is the orifin and insertion of teres major?
origin- inferior angle of scapula
insertion- medial lip of bicipital groove
what are the functions of teres major?
- medial rotation
- stabilisation of shoulder during abduction (eccentric cintraction)
what is a common rotator cuff injury?
- supraspinatous- due to repeated overhead activities
- happenes because limited space for tendon under the corocoacromial arch
what is the blood supply to the rotator cuffs?
- scapular anastamosis of the subclavian and axillary arteries
what is the nerve supply to the rotator cuff muscles?
suprascapular nerve- branch from superior trunk goes to supraspinatous and infraspinatous
shoulder region is also supplies by the posterior cord;
what do the different branches of the posterior cord innervate?
deltoid and teres minor- axillary
triceps brachii- radial
upper and lower subscapular nerves- subscapularis and teres major
thoracodorsal nerve- latisimus dorsi
what are the borders of the quadrangular space?
superior- teres minor
inferior- teres major
lateral- humerus
medial- long head of triceps
what structures are found in the quadrangular space?
- axillary nerve
- axillary artery
