Back muscles Flashcards
2 bones that extrinsic back muscles usually act on
humurus and scapula
2 general innervation of extrinsic back muscle
brachial plexus and ventral rami
innervation of intrinsic back muscle
dorsal rami
on which bone does intrinsic back muscle act on ?
vertebral column
2 bones involved in shoulder girdle
clavicle and scapula
2 joints involved in shoulder girdle
acromicoclavicular and sternoclavicular
2 bones involved in shoulder joint
glenoid cavity of scapula
head of humerus
Hilton’s law
a nerve that supplies the muscle moving a joint will also provide sensory supply to the joint.
Insertion and action of trapezius (3 actions)
spine of scapula thus acting on scapula 1. Adduction of scapula (retraction) 2. elevation and depression of scapula 3. raise arm above horizontal level
innervation of trapezium
spinal accessory nerve (CN XI)
Insertion and action of latissimus dorsi
insertion : medial side of humerus thus acts on humerus 1. adduction of humerus 2. medial rotation of humerus 3. extension of humerus
innervation of latissimus dorsi
thoracodorsal nerve
Insertion and action of rhomboid
acts on scapula
- adducts/retract scapula
innervation of rhomboid
dorsal scapular nerve
Insertion and action levator scapulae
elevate scapula
innervation of levator scapulae
dorsal scapular nerve
use of serratus posterior superior and inferior
acessory muscles for respiration
5 scapular muscles
deltoid
supraspinatus
infraspinatus
teres minor and major
action of supraspinatous
inserted at greater tubercle of humerus
so it abducts humerus (initiation of abduction)
innervation of supraspinatous
suprascapular nerve
action of infraspinatus
lateral rotation of humerus
innervation of infraspinatus
suprascapular nerve
action of teres minor
lateral rotation of humerus
innervation of teres minor
axillary nerve
action of teres major
inserted into medial side of humerus so - adduction of humerus - medial rotation - extension of humerus
innervation of teres major
lower subscapular nerve
action of deltoid muscle
abduction (20~90 degree of abduction)
innervation of deltoid
axillary nerve
Pectoralis major action
adduction of humerus
medial rotation
flexion
innervation of petoralis major
medial & lateral pectoral nerve
pectoralis minor action
stabilize scapula
innervation of petoralis minor
medial & lateral pectoral nerve
serratus anterior action
abducts scapula
innervation of serratus anterior action
long thoracic nerve
action of splenius capitis and cervicis (2)
bilateral contraction - extension of neck
unilateral contraction - lateral flexion and rotation of head
* for rotation we need oblique muscle.
3 muscles in erector spinae group
- spinalis
- longissimus
- iliocostalis
action of erecor spinae group (2)
bilateral contraction : extension of trunk
unilateral contraction : lateral flexion of trunk
3 muscles in transversospinalis group
- semispinalis (4-6 segments)
- rotatores (1-2 segments)
- multifidus ( 2-4 segments)
roles of transversospinalis group
stabilize vertebral column
Action of transversospinalis group(2)
bilateral contraction : extend trunk, neck, head
unilateral contraction : rotate to opposite side and laterally flex
Triangle of ausculation
medial : trapezius
lateral : medial border of scapula
inferior : latissimus dorsi
* best place to auscultate heart and lung sounds on the back
triangle of petit
also called lumbar triangle
- site of lumbar herniation (herniation of intestinal content)
- between lateral, external oblique and iliac crest
