Shoulder joint Flashcards
Superior muscles of the shoulder joint
Deltoid, Supraspinatus
Posterior muscles of the shoulder joint
Infraspinatus, Teres minor
Anterior muscles of the shoulder joint
Subscapularis, Pectoralis major, Coracobrachialis, Biceps brachii (stability)
Inferior muscles of the shoulder joint
Latissimus dorsi, Teres major,
Long head of Triceps brachii (stability)
Function of the deltoid
POWERFUL abductor
Functions of middle deltoid
abduction
functions of the anterior deltoid
Abduction
Flexion
Horizontal adduction
Internal rotation
Functions of supraspinatus
Weak abduction -(Works with deltoid)
Weak flexion
Stabilizes GH joint
2 Facts about supraspinatus
Important dynamic stabilizer in throwing
Most often injured of rotator cuff muscles
Motions of the infraspinatus
External rotation —Most powerful
Horizontal abduction
Extension
3 facts about the infraspinatus
Maintains posterior stability of humeral head in fossa
Effective when rhomboids stabilize scapula
2nd most injured rotator cuff muscle
motions of the teres minor
External rotation
Horizontal abduction
Extension
functions of the teres minor
Stabilizes humeral head in glenoid fossa
Functions similarly to infraspinatus; same actions
Motions of the subscapularis
Internal rotation
Adduction
Extension
Functions of the subscapularis
Stabilization of GH joint
Provides anterior and inferior stability
2 portions of the pectoralis major
clavicular portion
Sternocostal portion
functions of the clavicular portion of pectoralis major
Flexion
Horiz. adduction
Internal rotation
Abd/add
functions of the sternocostal portion of pectoralis major
Internal rotation
Horiz. adduction
Extension
Adduction
motions of the Coracobrachialis
Horizontal adduction
Assists in flexion
Assists in adduction
function of the coracobrachilais
Most functional in horizontal adduction
Stabilizes shoulder joint
motions of the latissumas dorsi
Adduction —Strong action
Extension
Internal rotation & horizontal abduction
functions of latissimus dorsi
One of most important extensors; powerful in chinning
motion of teres major
Extension (from flexed)
Internal rotation
Adduction (from abducted)
function of teres major
Effective only when rhomboids stabilize scapula
Works effective with lats
Flexors / Extensors
Anterior & posterior deltoid Coracobrachialis Pectoralis major - clavicular and sternal Latissimus dorsi Teres major SITS (-supra)
Abductors/adductors
Anterior/middle/posterior deltoid Pect major-clavicular (abd 90) Supraspinatus Latissimus dorsi Coracobrachialis Teres major Pect major-sternal clavicular (below 90 abd) Subscapularis
internal external rotators
Anterior posterior deltoid Teres major/minor Latissimus dorsi Pect major-both Subscapularis Infraspinatus
horizontal abductor/adductor
Anterior/Posterior deltoid Latissimus dorsi Infraspinatus Teres minor Coracobrachialis Pect major-both