muscles of the shoulder Flashcards
attachments of the trapezius muscle
superior nuchal line, the 12 thoracic vertebrae spinous processes , the clavicle and scapula
what movements do the trapezius do
upper fibres elevate the shoulder girdle
the middle fibres retract the shoulder girdle
the lower fibers depress the shoulder girdle
helps fixate the shoulder girdle
medial rotator during shoulder abduction
what movements do the levator scapulae do
elevates the shoulder girdle
attachements of the major and minor rhomboid major
spinous processes of the cervical and thoracic vertebrae and to the medial boarder of the scapula
movements of the rhomboid muscles
retraction of the shoulder girdle
attachments of the serratus anterior
to the ribs 1-9 and to the medial boarder of the scapula anteriorly
functions of the serratus anterior
pulls the medial boarder of the scapula toward the midline
also keeps the costal surface of the scapula closely opposed to the thoracic wall - prevents winged scapula
what are the 4 rotator cuff muscles
the subscapularis, infraspinatus, teres minor and the supraspinatus
attachment of the subscapularis
the subscapular fossa and the lesser tubercule of the humerus
attachment of the infraspinatus muscle
greater tubercule of the humerus and the infraspinatus fossa of the scapula
attachment of the teres major
- Inferior angle of the scapula – medial lip of intertubercular sulcus
attachment of the supraspinatus
the greater tubercule and the supraspinous fossa
what movements do the rotator cuff muscles do
subscapularis - medial rotation
infraspinatus is lateral rotation
teres minor is lateral rotation
supraspinatus is initial abduction
why can the teres major do extension of the arm
because it runs across the humerus anteriorly, its crossing the joint anteriorly so it helps extension
why does the supraspinatus do abduction
the tendon of this muscle runs under the coracoacromial arch and then connects to the greater tubercule, hence abduction
attachments of the deloid muscle
the deltoid tuberosity of the humerus, the spine of the scapula and the acormion of the scapula, and the clavicle
what are the fibres of the deltoid and what do they do
the fibres are somewhat named by attachment
clavicular deltoid fibers do flexion
the middle fibers do abduction
posterior fibres are extension.
what muscles help to do shoulder abduction
first part is the supraspinatus
the next part is the middle fibres of the deltoid
last part is so over 90 is the trapezuis and the serratus anterior
what bursa does not communicate with the shoulder joint.
the subacromial bursa.
what bursae communicate with the shoulder
subscapular bursa - covered by the subscapularis.
then theres the synovial sheath which surrounds the long head of the biceps
where does the pectoralis major connect
the clavicle, sternum and ribs, also to the lateral lip of the intertubercular sulcus
what movements does the pectoralis major do
at the clavicular head it flexes the enxtended humerus.
sternocostal it extends the flexed arm
both heads also do adduction of the shoulder and medial rotation
where does the latissmus dorsi connect
the spinous processes of the thoracic and lumbar vertebrae also attaches to the throacolumbar fascia and the iliac crest. laterally to the floor of the intertubercular sulcus
what movements does the latissmusi dorsi do
adduct the shoulder, medially rotate and extend the shoulder
