Back Muscle Innervations and Actions Flashcards
rhomboid major
dorsal scapular nerve
Role: Retraction and rotation of scapula
rhomboid minior
dorsal scapular nerve
Role: Scapular movement (elevation)
lasttisimus dorsi
thoracodorsal nerve
Role: Internal rotation of the shoulder joint (arm), trunk flexion
(unilateral), arm adduction
trapezius
accessory nerve XI
Role: Movement of the scapula and support of the arm
Upper/Superior: Elevate and upwardly rotate the scapula; Extend
the neck
Middle: Adduct, Retract Scapula
Lower/Inferior: Depress scapula
infraspinatus
suprascapular nerve
Teres minor
axillary nerve
Lateral/external rotation
of the arm
Teres major
Lower Subscapular nerve
Adduction and rotation of the arm
medially; help extend humerus from
Levator Scapulae
Dorsal scapular nerve (C5)
Role: Elevates the scapular bone
SERRATUS POSTERIOR SUPERIOR
Intercostal nerves 2-5
Role: Elevate upper ribs during inhalation
SERRATUS POSTERIOR INFERIOR
Intercostal nerves 9-12
Depresses lower ribs during forced expiration
SPLENIUS CAPITIS
Branches of posterior rami of C2-C3
Role: Extensor and flexor of neck (lateral)
SPLENIUS CERVICIS
Branches of posterior rami of lower cervical spinal nerves
Role: Position head and neck (lateral flexion, extension and rotation)
Semispinalis m
Role: Extension of head and spine (cervical and thoracic); lateral flexion and rotation of head
Multifidus
Role: Extension, lateral flexion and rotation of spine
Rotatores
Role: Extension and rotation of spine
subscapularis
subscapular n.
Arm interal rotation;
stabilizes humeral head in glenoid cavity
Teres minor
Axillary n. (C5-C6)
External rotation and ADDuction of arm
Infraspinatus
Suprascapular n. (C5-C6)
Arm external rotation;
sabilize humeral head in glenoid cavity
Supraspinatus
Suprascapular n. (C5-C6)
ABduction of the arm;
pulls head of humerus medially towards glenoid cavity
deltoid
Axillary nerve
Abduction, flexion and
extension of the arm
