anatomy of the shoulder region Flashcards
What composes the pectoral girdle
Clavicle and scapula
What are the skeletal components of the shoulder
pectoral girdle, humerus, 2 joints: glenohumeral and acromioclavicular joint.
what are the Ligaments of the shoulder region
coracoclavicular ligaments, coracoacromial ligaments
acromioclavicular ligaments,
glenohumeral (superior/ medial and inferior)
Outline the coracoclavicular ligaments
2 parts, major stabilizing ligament
outline the coracoacromial ligament
forms arch (for head of the humerus) prevents superior dislocation
Outline the glenohumeral joint and its actions
ball n socket joint, between large head of the humerus and glenoid fossa.
abduction/ adduction, flexion/ extension, circumduction and lateral/medial rotation
Outline abduction in the shoulder region
Performed by deltoid
origin: spine of scapula, acromion and clavicle
insertion: deltoid tuberosity
outline adduction in the shoulder region
performed by latisimus dorsi and pectoralis major.
abduction/ adduction of the arm
glenohumeral joint accommodates and rotation of the scapula increase the range of movement.
Why is the glenohumeral joint so unstable
The humeral head is very large and the glenoid fossa is very shallow
What factors increase joint stability in the shoulder
1) Corachoacromial arch prevents superior dislocation
2) glenohumeral ligaments support an anterior aspect of joint
3) glenoid labrum, skirt surrounding glenoid foss- fibrocartilage ring.
4) long head of biceps n triceps, splint the joint above and below
5) tendons of the rotator cuff muscles
Name the rotator cuff muscles
Teres minor, infraspinatus, superspinatus, subscapularis
Where does subscapularis originate and insert, where is it found
sits in subscapular fossa,
origin: ant surface of the scapula
insert: lesser tubercle
Where does supra/infraspinatus and teres minor insert into
They insert into the greater tubercle
What are the functions of the rotator cuff muscles
supraspinatus- initiate abduction
infraspinatus- lateral rotation
teres minor- lateral rotation
Outline the function of teres major
Performs radial rotation
stabilizes humerus during abduction but doesn’t cuff so it isn’t classified as an rcm
inserts into the medial lip of the bicipital groove
What is the most common rotator cuff injury
supraspinatus impingement, most commonly injured
as there is limited space for tendon below the coracoacromial arch
Outline the nerve supply to the shoulder region
the superior trunk has the subscapular nerve coming off to supply the supra/ infraspinatus
posterior cord supplies the shoulder region,
upper and lower nerves supply the subscapularis, trees major
thoracodorsal nerve supplies lattisimus dorsi
What are the borders of the quadrangular space
teres minor (sup border), major (inf border) the humerus ( lateral border) and long head of the tricep (medial border)
