4. Back Flashcards
Erector spinae - iliocostalis
Location
Action
L-most lateral muscle group of erector spinae muscles; extend from pelvis to neck
A-extend and laterally flex the vertebral column
Erector spinae - longissimus
Location
Action
L-immediate tripartite muscle group of erector spinae; extend by many muscle slips from lumbar region to skull; mainly pass b/w transverse processes of the vertebrae
A-thoracics and cervicis act to extend and laterally flex vertebral column
Erector spinae - spinalis
Location
Action
L- most medial muscle column of erector spinae; cervicis usually rudimentary and poorly defined
A-extends vertebral column
Semispinalis
Location
Action
L- composite muscle forming part of dell layer of intrinsic back muscles; extends from thoracic region to head
A-extends vertebral column and head and rotate them to opposite side; acts synergistically w/ sternocleidomastoid muscle of opposite side
Splenius
Location
Action
L- broad bipartite superficial muscle (capitis and cervicis parts) extending from upper thoracic vertebrae to skull
A- extend the head; when splenius muscles on one side are activated; head is roared and bent laterally toward same side
