Download instability

Slide 1
Spinal Stability
Tara Jo Manal PT, SCS, OCS
Slide 2
Clinical Instability

Loss of the ability of the spine under
physiologic loads to maintain its pattern of
displacement so that there is no initial or
additional neurological deficit, no major
deformity, and no incapacitating pain
» White and Panjabi
Slide 3
Clinical Instability






Anatomic Considerations
Biomechanical Factors
Clinical Considerations
Treatment Considerations
Recommended Evaluation system
Recommenced management
– Recorded cases of patient post-polio with
cervical paralysis and no instability if bones and
ligaments remain intact
Slide 4
Biomechanics of Spinal
Cord and Nerve Roots
Cord does not slide up and down (v.small)
 Accordion like- lengthen on one side and
shorten on the other (ie sidebending)
 Greatest stretching occurs between C2 and
T1 (<20%)
 Injury is due to loss of cord elasticity,
displacement or space occupying lesions
 High compliance in the axial plane, less in
the horizontal plane

Slide 5
Types of Instability

Kinematic

Component Instability
– Motion increased
– Instantaneous axes of rotation altered
– Coupling characteristics changed
– Paradoxical motion present
– Trauma
– Tumor
– Surgery
– Degenerative changes
– Developmental chages
Slide 6
C0-C1

Unstable in childhood
 Dislocations are
generally fatal
 Instability identified by
x-ray
– Rotation >8° is
pathological
– Translation > 1 mm
Slide 7
C1-C2





Instability due to dens
fracture
Vertebral translation or
Rotation
Bone spur
Little contribution of the
facet/capsule
compared to dens and
ligamentous ring
Alar ligament test
– C1-C2 > 56° is
abnormal
Slide 8
Jefferson Fracture
C1 Ring Distruption, overhang of lateral masses of C2
Slide 9
C2-T1

Failure consists of
injury to posterior and
anterior elements
 Unilateral facet
– Root symptoms

Bilateral facet

Burst Fracture
– Spinal medullary injury
– Horizontal displacement
– Spinal cord injury
Slide 10
Recognizing Instability
History of a flexion injury
 Widening of interspinous space
 Subluxation of a facet joint
 Compression fracture of adjacent vertebrae
 Loss of normal cervical lordosis

Slide 11
Thoracic Instability

T1-T10
 Overall greater
stiffness
 Spinal cord damage
with injury ~10%

T11-L1
 Spinal cord damage
with injury ~4%
Slide 12
Lumbar Instability
L1-S1
 3% Fracture and dislocation have
neurological signs
 Disconnect between displacement and
neurological signs
 >4.5mm or 15%
 Facet has a crucial role in stability (rot and
SB)

Slide 13
Stabilization of the Spine

Passive system

Active system

Neural control
Slide 14
Muscular Control of the
Spine

Rotatores and Intertransversarii
Function primarily as force transducers
 Position Sensors
 Electrically silent with large rotations
(involving Abs)

Slide 15
Muscular Control of the
Spine
Extensors – Longissimus, Iliocostalis
 Thoracic area ~75% slow twitch fibers
 Lumbar area ~50% mix
 Lumbar area- in flexion provide a
compressive force in the lumbar to limit
shear

Slide 16
Muscular Control of the
Spine

Extensors – Multifidi
Span only a few joints
 Produce extensor torque/resistance
 Only small amounts of rotation or SB
 Contribute to correction or support

Slide 17
Muscular Control of the
Spine
Abdominal Muscles
 Rectus

– Major trunk flexor
– Active with sit-up and curl-ups
– Little to no evidence to support upper/lower
differentiation
Slide 18
Muscular Control of the
Spine

Abdominal Wall- Ext/Int Oblique

Torso Rotation and Lateral flexion
Slide 19
Muscular Control of the
Spine

Abdominal Wall-Transverse abdominis
Beltlike support and generation of intraabdominal pressure
 Delayed onset during ballistic movements in
patient’s with LBP

Slide 20
Muscular Control of the
Spine
Psoas
 Primarily hip flexor
 Compressive force to spine during
contraction
 Questionable contribution to spine stability

• If so, under high hip flexor forces
Slide 21
Muscular Control of the
Spine

Quadratus Lumborum
Highly involved with spine stabilization
 Active in flexion, extension and SB
 During Lifting, increased oblique activity
followed increases in QL

Slide 22
Muscular Control of the
Spine
Deep Rotators- position sensors
 Extensor Group

– Generate large extensor moments
– Generate posterior shear
– Affect one or two segments
Slide 23
Co-activation of the
Muscular Spine

90N force (20lbs)
creates buckling
without muscular
forces
 Co-contraction
increases support
against buckling
Slide 24
Muscular Stability
Continuous contraction
 ~10% MVIC of abdominals
 No single muscle is critical one

Slide 25
Joint Shear Testing
Slide 26
Generalized
Ligamentous Laxity
Elbow Hyperextension >10°
 Passive Hyperextension of 5th finger >90°
 Abduction of thumb to forearm
 Knee Hyperextension >10°
 Forward flexion hands to floor (knees ext)


Tested Billateral: Total score:
/9
Slide 27
Neutral Spine
Slide 28
Abdominal Bracing
Slide 29
Curl-up Beginner

Maintain lordosis with hands
 Attempt to lift head (little to no motion)
 Raise head and shoulders (no cervical flexion)
 One leg flexed one extended
Slide 30
Curl-up Intermediate

Elbows off the table
Slide 31
Curl-up Advanced

Fingers on forehead
Slide 32
Side Bridge Remedial
Slide 33
Side Bridge Reverse

Lift legs off the bed
Slide 34
Side Bridge Knees
Flexed

Knees flexed
Slide 35
Side Bridge Intermediate

Legs extended
Slide 36
Side Bridge Intermediate
Variation

Legs extended
 Rolling of torso on legs
Slide 37
Side Bridge Advanced
Slide 38
Birddog, Remedial

Hands and knees,
raise one hand off bed
 Progress to hand and
opposite knee
Slide 39
Birddog, Beginner’s

Raise one arm or leg at
a time
Slide 40
Birddog, Intermediate

Raise one arm and leg
at a time
 Hold 6-8 seconds
Slide 41
Birddog, Advanced

Raise one arm or leg at
a time
 Avoid Returning to the
bed, sweep and
resume
Slide 42
Isometric Rotation

Isometric Activity