The Spine Flashcards
What is the scope of LBP?
At least 80% of people with have back pain at some point in their lives.
Do patients with low back pain have weaker spinal musculature.
There is little deficit in people with acute back pain, but patients with chronic pain typically demonstrate weak abs and extensor muscles. Normally trunk extensors are 30% stronger than trunk flexors.
Discuss Williams’ Flexion exercises.
Williams believed that the basic cause of back pain was caused by poor posture and that lordosis led to inc dysfunction in the posterior aspect of disks. The goals of the exercises are to open the intravertebral foramina and to stretch the back extensors, hip flexors, and facets while strenghtening abs and glutes.
Exercises include pelvic tilts, Knee-to-chest exercises, hip flexor stretching, and crunches.
Explain McKenzie’s philosophy and classifications.
Mckenzie believed that the disk was the primary sours of pain but that flexion was the culprit, due to prolonged sitting positions and lack of extension. He believed the accumulation of forces led to early dysfunction in posterior disk. He classified disorders 3 ways:
Postural Syndrome: sedentary occupation, less than 30 years old, midline pain, no referred pain, no pain induced by movement, only prolonged positioning
Dysfunction Syndrome: sedentary occupation, age 30+ years old, often sedentary occupation, back pain at end ROM, restricted ROM c shortened soft tissues
Derangement Syndrome: Typically 20-55 years (working age) sudden onset, possible radiatio nof pain, paresthesias, migrating pain, exacerbated by certain movements
Describe the typical treatment for postural syndrome.
Postural correction advice, use of lumbar rolls, active and passive extension exercises
Describe the typical treatment for dysfunction syndrome.
Postural education, flexion/ext and/or lateral deviation stretching and coorection, mobilization and manipulation into restricted ROM (basically the same as postural, with side bending and mobilization/manips added)
Describe the typical treatment for derangement syndrome.
Reduction of derangement, postural education, repeated ext in prone or standing, use of lumbar supports, address lateral devation, ext manipulation as necessary. When pain is intermittent, add flex exercises in recumbent position, progressing to standing. Always follow flex exercises with ext.
Are flexion or extension exercises more effective for LBP?
Research is inconclusive. McKenzie is usually better than back school. Flexion appeared to be more helpful in increasing sagittal mobility but extension exercises are preferred by patients. Flexion and extension coupled c manipulation is helpful.
What is the reliability of McKenzie evalation techniques?
Poor inter-tester regardless of post-grad training
What are the implications of weak multifidi in relation to LBP?
The multifidus is the larges, most medial, and most used extensor muscle group, contributing to 70% of the stiffness from muscle contraction in the neutral zone of the lumbar spine. Research demostrates multifidus wasting in LBP patients. Selective training significantly increases cross-sectional area and helps prevent and rehab chronic pain.
Are intensive exercise programs more effective than gentle programs for LBP?
Yes. Intensive programs with exercises directed at specific muscle groups, movements, and control. Genle programs where patient gradually increases ADLs as tolerated and walks is not as effective.
Describe Fryette’s laws of spinal biomechanics.
- Spine neutral: coupling is contralateral
2. Spine non-neutral: coupling ipsilateral
Describe spinal coupling (updated, not Fryette).
C1-C2 has contralateral coupling.
Cervical and upper thoracic: ipsilateral
Mid and Lower thoracic: inconsistent
Lumbar: contralateral if rotation first
However, movement is variable among different people and even in different regions in the same person
Describe general trends in spinal ROM.
In general, flex/ext and lateral flex increase from cranial to caudal. Rotation decreases cranial to caudal.
Describe normal cervical ROM.
Cervical flex: 50*
Cervical ext: 60*
Cervical SB: 45*
Cervical rotation: 80*
Describe normal lumbar ROM.
flex: 90*
SB L, SB R, ext: 25*
Define scoliosis.
Any abnormal curvature in the coronal plane >10*. Anything less is spinal asymmetry.
Describe spinal ligaments from anterior to posterior.
(upper cervical name change)
Anterior longitudinal ligament: ant VB. (alantoaxial and ant alanto-occipital membrane)
Post Long. Lig.: post VB (tectoral ligament)
Ligamentum flavum: ant lamina to sup lamina (posterior alanto-occipital membrane)
interspinous ligament: SP to SP (none)
Supraspinous ligament: tips of SP (ligamentum nuchae)
Transverse ligament: body of C1 to body C1
Alar ligament: dens to occipital condyles
Apical ligament: tip of dens, foramen magnum
Describe the anatomy of the intervertebral disk.
Each motion segment has one disk (except C1-C2). Disk is avascular with an outer annulus fibrosis and inner nucleus pulposus and a cartilagenous end plate. NP acts as a shock transmitter (not absorber because it is water) and transmits loads from NP to surrounding tissue (changes vertical forces to horizontal forces so that the surrouding tissues act as shock absorbers). Fibers are arranged in perpendicular lamellar fibers aranged at 45* angles. Disks are taller anteriorly in the cervical and lumbar spine, posteriorly in the thoracic spine (causes the curves).
How do disks obtain nutrition?
Through local diffusion. Exercise can help pump the disk which aids in solute transport and possibly by increasing external local vascularity.
Sidelying or hooklying facilitates nutritional pressure changes (approx 80% of nutrition absorbed at night is within the first hour of rest, so laying down during the day may double nutrition)
Describe facet orientations.
Cervical: facets are 45* to vertical in the sagittal plane
Thoracic: 60* to vertical in sagittal plane, leading to increased rigidity and dec rotation
Lumbar: vertical, with facets oriented in a v shape with the point anterior
Describe spinal loading in different postures.
Measured at L3-4 by Nachemson Lowest load is sidelying (25%) Standing (100%) Seated (145%) Standing with forward bend (150*) Sitting with forward bend (180*) loads are lower during supported than unsupported sitting because part of the weight of the upper body is supported on the backrest. Backward inclination and use of a lumbar support further reduce loads.
What are spinal canal dimensions?
1.5 to 2 cm (spinal cord is 1cm in diameter, stenosis occurs when canal is less than 1.5 cm)
Two levels of enlargement correlate with levels of upper (C4-T1) and lower (L2-S3) innervation. The conus medullaris starts at T10-T11 disk level. The L1-L2 disk level marks the end of the conus medularis and start of the cauda equina
How are facet joints innervated?
by the dorsal primary ramus 2 branches (superior and inferior) innervate the facet above and below the level of the nerve root (ex: The L2-L3 facet is innervated by the descending branch of L1 and the ascending branch of L3)
Where is the nerve root in relation to the pedicle and disk?
In the cervical spine, the spinal NR exits directly lateral from the spinal canal adjacent to the corresponding disk (just superior to pedicle for which it is named). The numbering changes at C7-T1 so that the C8 NR passes superior to T1 pedicle.
In the lumbar spine, the NR passes just inferior to the pedicle for which it is named (usually superior to disk at that level)
How does spinal movement affect the size of intervertebral foramen?
flexion increases size by approx 20%, extension decreases by 20%
What happens during the straight leg raise test?
The sciatic nerve is sigmoid in shape (loose). The first 35 degrees, slack is being taken up along the nerve prior to the NR. From 35 to 70 degrees the NR moves. Above 70*, movement stops and tension is placed on structures.
What muscles are involved in lumbar flexion and extension?
flexion: abs, vertebral part of psoas, erector spinae/post hip muscles to control. At full range, muscles act as passive restraints.
Ext: pelvis tilts backwards and process reverses using above sequence
Describe the effect of situps on spinal loading.
A situp increases disk pressure >2x.
A reverse curl is <1.5x.
Ab crunch: less than situp
What are differences in lumbar spine kinematics between patients with chronic LBP and normal subjects?
Chronic LBP results in earlier and longer activation of erector spinae, suggesting a change to motor program from a open to closed loop system.
What are the effects of lumbar diskectomy on trunk muscles?
At 2 months, approx 35-45% dec muscle strength, suggesting importance of rehab.
What is the effect of leg length discrepancy on spinal motion?
asymmetrical lateral side bending toward lengthened side (may lead to scoliosis with the apex on short side)
What are the common conditions that can lead to pain and disability (regarding facet joint)?
1) acute synovitis/hemarthrosis
2) stiffness resulting from collagen cross binding following injury
3) mechanical block possibly due to torn or separated meniscoid (in lumbar facet joints)
4) painful capsular entrapment
5) degenerative arthrosis
Discuss potential sources of pain associated with dysfunction of the disk.
Nerve endings are found in the outer 2-3 layers of the disk. As a disk degenerates, it may become engorged with blood vessels in an effort to repair the disk. Sympathetic nerves may accompany these blood vessels and inc pain.
Why does disk herniation occur?
The first changes are NP leaking laterally. The inner annulus has few fibers while the outer annulus has many fibers. The inner annulus degenerates but tears begin at the outer annulus and spread inward allowing the NP to deform. Healing is possible but is very slow.
