Lumbar & sacral regions w/ function Flashcards
Describe lumbar facet arthrokinematics for flexion
- inferior facet of superior vertebra slides superior
Describe lumbar facet arthrokinematics for extension
- inferior facet of superior vertebra slides inferior
Describe lumbar facet arthrokinematics for rotation
- VERY limited
- IF moving right; left inferior facet will contact L superior facet and R inferior facet will gap from R superior facet
Describe lumbar facet arthrokinematics for lateral flexion
- ipsilateral facet slides down
- contralateral facet slides up
What happens to the contact area and contact pressure of the lumbar facets at extremes of flexion & extension?
Extreme flexion:
- contact area decreases which increases contact pressure
Extreme extension:
- contact area increases which decreases contact pressure
How does lumbar flexion affect intervertebral foramen & nerve roots and discs?
IV foramen & nerve roots:
- increases (opens) IV foramen
- decompresses nerve roots exiting nerves
Discs:
- anterior compresses
- nucleus migrates posterior
How does lumbar extension affect intervertebral foramen & nerve roots and discs?
IV foramen & nerve roots:
- decreases (closes) IV foramen
- compresses nerve roots exiting nerves
Discs:
- posteriorly compresses
- nucleus migrates anterior
What position reduces pressure on the lumbar discs?
- full, sustained lumbar extension
What is centralization?
- pain that was radiating down the LE’s begins to migrate back to the low back
- suggests reduced contact pressure b/w disc material & nerve root
Describe lumbo-pelvic rhythm during forward bending
Lumbar flexion:
- 1st 25% of movement
- 45 degrees flexion
Hip flexion:
- last 25% of movement
- 60 degrees flexion
What are the consequences of limited hip flexion?
- increased excessive lumbar flexion
- more pressure on discs increases degeneration
- over stretches T-L fascia
- reduces ability of tissues to limit flexion
What are the consequences of limited lumbar flexion?
- excessive hip flexion
- more demand of hip extensors
- leads to greater compressive loads at hip joints
- painful w/ arthritis
Describe lumbo-pelvic rhythm during return from forward bending
Hip Ext:
- early phase hip extensors active when external force greatest on lumbar spine
Lumbar Ext:
- middle phase lumbar extensors active when EMA reduced
Muscles relax in erect standing if LoG through/posterior to hip
How does the T-L fascia help stabilize the lumbar spine?
- many muscle attachments
- QL, erector spinae, multifidi, glute max, lats, transversus abdominis, internal oblique
How do the transverse abdominis and internal obliques help to stabilize the lumbar spine?
- they fuse together to form a central tendon that connects directly w/ middle layer of T-L fascia
- called lateral raphe
What happens to the multifidi in patients with low back pain?
- becomes atrophied
- increased fat content
- muscular inhibition
What muscles would you want to strengthen to increase lumbar stability?
- IO & Trans Abd
- multifidi
- active b/f perturbations occur w/ electro studies
How does anterior pelvic tilting affect the lumbar spine?
- increases lumbar lordosis
What happens at the L5/S1 junction with increased lumbar lordosis?
- increase sacrohorizontal angle which increases anterior shear force on L5/S1
Which structures resist anterior shear in the L5/S1 region?
- intervertebral discs
- facet joints & capsule
- ALL
- iliolumbar ligaments
What is spondylolisthesis?
- vertebral slipping
Pars articularis:
- fractures causing slipping of vertebra
What lumbar motion would you want to avoid with a spondylolisthesis?
- avoid extension exercises/activities if progressive or unstable
How does posterior pelvic tilting affect the lumbar spine?
- decreases lumbar lordosis
Which muscles form force couples for pelvic tilting when the lumbar spine is stabilized?
Ant Tilt:
- erector spinae
- sartorius
- iliopsoas
Post Tilt:
- glute max
- hamstrings
- rectus abdominus
