Scapulohumeral( intrisic Shoulder) Muscles Flashcards
Deltoid distal attachment
Deltoid tuberosity of humerus
Deltoid proximal attachment
Lateral third of clavicle
Acromion and spine of scapula
Deltoid intervention
Axillary nerve c5 c6
Deltoid action
Clavicular(anterior) part flexes and medially rotates the arm
Acromial( middle) part abducts arm
Spinal(posterior) parts extends and laterally rotates arm
Supraspinatus proximal attachment
Supraspinous fossa of scapula
Supraspinous distal attachment
Greater tubercle of humerus (superior facet)
Supraspinatus innervation
Suprascapular nerve c4 c5 c6
Supraspinatus action
Initiates and assists deltoid in abduction of arm and acts with other rotator cuff muscles
Infraspinatus proximal attachment
Infraspinous fossa of scapula
Infraspinatus distal attachment
Greater tubercle of humerus (middle facet)
Infraspinatus innervation
Suprascapular nerve c5 c6
Infraspinatus action
Laterally rotate arm; help hold humeral head in glenoid cavity of scapula
Teres minor proximal attachment
Middle part of lateral border of scapula
Teres minor distal attachment
Greater tubercle of humerus(inferior facet)
Teres minor innervation
Axillary nerve c5 c6
Teres minor action
Laterally rotate arm; help hold humeral head in glenoid cavity of scapula
Teres major proximal attachment
Posterior surface of inferior angle of scapula
Teres major distal attachment
Medial lip of intertubercular groove of humerus
Teres major innervation
Lower subscapular nerve c5c6
Teres major action
Adducts and medially rotates arm
Subscapularis proximal attachment
Subscapular fossa(most of the anterior surface of scapula)
Subscapularis distal attachment
Lesser tubercle of the humerus
Subscapularis innervation
Upper and lower subscapular nerves
C5c6c7
Subscapularis action
Medially rotates and adducts arm
Help hold humeral head in glenoid cavity
The tendons of the SITS blend with the joint capsule of the glenohumeral joint, reinforcing it as the musculotendinous rotator cuff, which…
Protects the joint and gives it stability. Tonic contraction of these muscles hold the relatively large head of the humerus firmly against the shallow glenoid cavity
