Lumbar Part 2 Flashcards
Trunk Flexion
First gravity initiates
movement
Trunk flexion part 2
Erector spinae contract ______, assisted by
eccentrically
thoracolumbar fascia and posterior ligaments
Trunk Flexion part 3
after about 2/3 of flexion, erector spinae are
relaxed
Trunk flexion part 4
What controls the movement after muscles relax?
ligaments
Trunk Extension
What initiates trunk extension from a fully flexed position?
pelvis extends on hips
Trunk Extension
Which muscles initiate the motion and which muscles help complete the motion?
Initiate: Glute max
Complete: Erector spinae
Trunk Extension
Which joints extend first, and which joints help complete the motion?
Pelvis extends first
facet joints complete motion
What happens to the erector spinae moment arm as the pelvis posteriorly tilts
decreases as it becomes parallel with body
Trunk Extension
Explain why hip extensors contracting first helps limit stress on the lumbar spine & erector spinae
they move the moment arm of the bodyweight from perpendicular to parallel, lessening stress on the erector spinae
Lumbopelvic Rhythm
Exact degrees of motion for spine and hips/pelvis is variable, however in most adults it is usually:
Forward Flxion of trunk:
About 45 deg is
About 60 deg is
45: thoracolumbar spine flexion
60: anterior tilting of pelvis by rotation of pelvis on femoral head (flexion of hips)
Extension of trunk from forward flexed position:
About 60 deg is:
About 45 deg is:
60: posterior tilting of pelvis by rotation of pelvis on femoral heads (extension of hips)
45: thoracolumbar spine flexion
What are the benefits of lumbopelvic rhythm
decreases stress on lumbar spine and erector spinae
Can you explain why a patient with back pain may exhibit Gowers Sign?
hypomobility —> more stress on ligaments
erector spinae weakness
Anterior pelvic tilt accentuates
lumbar lordosis
Which muscles are contracting in anterior pelvic tilt
Rectus femoris and iliopsoas
What is the effect of a full anterior pelvic tilt on the intervertebral foramen and nucleus pulposis?
less space in IV foramen
nucleus pushed anteriorly
Posterior pelvic tilt reduces
lumbar lordosis
Which muscles are contracting in posterior pelvic tilt
abs (rectus)
also glute max
What is the effect of a full posterior pelvic tilt on the intervertebral foramen and nucleus pulposis?
More space in foramen
nucleus pushed posteriorly
Greatly exaggerated lumbar lordosis (“lordotic posture”)
Which muscles may be weak?
Which muscles may be tight
weak: abs/glute max
tight: hip flexors
Greatly exaggerated lumbar lordosis (“lordotic posture”)
Which joints have increased compressive forces
Effect on nucleus pulposis?
Facets
nucleus pushed anteriorly
Greatly exaggerated lumbar lordosis (“lordotic posture”)
Increased shearing forces - favors development of
spondylolisthesis
Decreased lumbar lordosis (“flat back posture”)
Which muscles are weak?
Tight?
weak: hip flexors/erectors
tight: abs/glutes
Decreased lumbar lordosis (“flat back posture”)
Which joints have increased compressive forces?
Effect on nucleus
intervertebral body joints (compressed)
Nucleus pushed posteriorly