trunk musculature - exam 1 Flashcards
what everyday position has a higher load on the NP in the lumbar spine?
bending over (at lumbar spine) to lift a heavy object
-in general, holding/moving a heavy object increases load on the NP in the lumbar spine
list these seated positions in order from highest pressure to NP –> lowest pressure to NP
- slumped
- leaning back
- straight sitting
highest:
- slumped
- straight sitting
- leaning back
lowest:
what everyday position has the least amount of load to the NP in lumbar spine?
laying supine
what happens to the lumbar multifidus following a low back injury?
experiences a number of morphological and neurophysiological changes
– one being a segmental atrophy which develops at the level of pathology, on the symptomatic side and as quickly as 24 hours after the injury
what has happened if a disc has bulged/protruded?
nucleus migrates but remains contained in annulus
protrudes beyond posterior rim of vertebral body
what is a disc herniation?
nucleus has herniated through the annulus fibrosis and PLL
what is extrusion?
nucleus migrates thru the outer annulus
extrude through epidural space
what is free sequestration?
nucleus migrates and breaks away from annulus
lodged or break off
what is the greatest injury risk during sit ups? how would this happen?
if hip flexion occurs without the trunk curl
this may happen because of lack of abdominal strength, hip flexor dominance or an inability to flex the lumbar spine
what does hip flexor contraction without a trunk curl cause?
dangerous anterior shear forces from hyperextension of the lumbar spine
because the hip flexors are attached to the front of the lumbar spine, the sit up phase will cause the torso to lift, pulling on the unstable extended spine
what is occurring during the trunk flexion phase of the full sit up?
internal obliques and rectus abdominis are most active muscles.
as trunk is pulled towards pelvis, posterior tilt happens
what is occurring during the hip flexion phase of the full sit up?
continued activation of abdominals but hip flexors are activated and are prime movers through the completion of the movement
true or false. the axes of rotation during the full sit up shifts from the abdominals to the pelvis when going from the trunk flexion phase to hip flexion phase
true
why would a full sit up be advised against?
causes more pressure in the discs and more spine flexion
if you are doing full sit ups and have weak abs, what happens instead?
hip flexors dominate and cause early hip flexion. this puts you at a shear risk
when doing a diagonal sit up, what is happening?
incorporates trunk flexion and axial rotation
right EO acts synergistically with left IO muscle
bilateral activation of rectus abdominis and transversus abdominis
during a standard sit up, are lateral flexion torques active?
no they are neutralized
when a patient lifts their arms, what muscle was contracted before or shortly after the deltoid muscle?
transversus abdominis.
- was not influenced by movement direction, which supports that this muscle helps with spinal stiffness
a patient moves their arms and body but has LBP. what happened to the TA?
contraction was significantly delayed with all movements
local muscles:
– location and length?
– controls:
– ____ density muscle spindles
– varying angles act as ______
–
– deep and short
– precise alignment and stiffness
– high
– guidewires
global or extrinsic muscles:
– location and length?
– _____ generators
– provides?
– superficial and long
– torque
– strong links between regions
what is a diastasis recti?
when the rectus abdominis separates along the linea alba
– looks like an indent along the linea alba
what are the muscles of the posterior trunk?
3 layers:
superficial:
– trap, lats, rhomboids, levator scap, SA
intermediate:
– serratus posterior superior, serratus posterior inferior
deep:
– erector spinae group (spinalis, longissimus, iliocostalis)
– transversospinal group (semispinalis, multifidi, rotators)
short segments group (interspinalis, intertransversarius)
what does the erector spinae group generally do? location?
gross movements
large ext torque
common tendon at sacrum
deep to thoracolumbar fascia
one hand width from SPs
what does the transversospinal group generally do? location?
contralateral rotation & SB
bilateral contraction for extension
medial fibers
TP of one vertebra to SP of more superiorly located vertebra
multifidi:
– runs:
– TP to SP ___
– thickest in which region?
– fills space where?
– ____ cross sectional area
– what happens with injury/pain?
– what surrounds them?
– post. sacrum to C2
– TP to SP 1 or 2-4 vertebrae above
– thickest and most developed in lumbar region, 2/3 muscular stabilizing capacity
– fill the space between TP/SP
– large cross sectional area
– atrophy quickly
– TA and thoracolumbar fascia surrounds them
what does the short segments group do in general? characteristics?
interspinalis: extension
intertransversarius: SB
rich in muscle spindles - sensory feedback
short length
crosses only 1 intervertebral junction
most developed in cervical region
bilateral and blends with interspinous ligament
what are the muscles of the anterior-lateral trunk?
rectus abdominis (strap like)
obliquus externus abdominis (wide/flat)
obliquus internus abdominis (wide/flat)
transversus abdominis (wide/flat)
what does the anterior-lateral trunk muscle group do?
support and protect viscera
increase intrathoracic and intra-abdominal pressure
what forms the linea alba?
anterior and posterior rectus sheaths
rectus abdominis:
– longest _____, smallest _______
– intersected by
– runs?
– fascicle length, cross sectional area
– 3 transverse fibrous bands, tendinous insertions
– xiphoid –> 5-7 cartilaginous portion ribs –> crest of pubis
external oblique:
– most ______ of lateral muscles
– fibers run:
– superficial
– inferior and medial (hands in pockets)
internal oblique:
– _____ to EO
– _____ cross sectional area of abs
– fibers run:
– deep
– largest
– superior and medial
what are the actions of the rectus abdominis?
flexes thorax and upper lumbar spine
posterior pelvic tilt
what are the actions of the EO?
SB
contralateral rotator
bilateral flexor of trunk
posterior tilt of pelvis
what are the actions of the IO?
ipsilateral rotator (synergist with opposite EO via linea alba)
SB
bilateral flexion of trunk
posterior pelvic tilt
increases tension in TL fascia
transversus abdominis:
– deep or superficial?
– attachments?
–deepest
– ribs - iliac crest - inguinal ligament - TL fascia
what are the actions of the transversus abdominis?
stabilization for other abdominal muscles
increases tension TL fascia
compression of abdominal cavity
Quadratus lumborum:
– located?
– attaches to?
– posterior abdominal wall
– IC and iliolumbar ligament
what are the actions of the quadratus lumborum?
bilateral: extension, vertical stabilization
unilateral: SB
“hip hiker”
what two muscles make up the iliopsoas and their locations?
iliacus (fossa and lateral sacrum)
psoas (TPs T12-L5 and discs)
what are the actions of the iliopsoas?
hip flexor
anterior tilt
lumbar extension
SB of trunk
what is an example of relative degree of stabilization?
erector spinae T/S ext or anterior pelvic tilt
flexion –> sacrum stable
pelvic tilt –> lumbar stable
the dorsal ramus forms nerves that innervate where?
innervates muscles, joints, skin of posterior trunk and neck
the ventral ramus forms nerves that innervate where?
muscle, joints, skin of anterior/lateral trunk, neck and extremities
ventral ramus:
– becomes:
– 4 major plexi are:
– innervation:
– an individual nerve or plexus
– C1-4, C5-T1, T12-L4, L4-S4 (most innervate limbs)
– individual intercostal and recurrent meningeal
dorsal ramus:
– branches from:
– innervates:
– every spinal nerve root
– innervating structures in post. trunk (except C1-2) and dermatome across most of posterior trunk. ligaments post. side of vertebrae, capsule of facets, dorsal ligaments of SIJ
