L16 - FOUNDATION OF SPINAL THRUST MANIPULATION Flashcards
IFOMPT: definition of spinal manipulation & description
Definition
Spinal manipulation = application of rapid movement to vertebral segments producing joint surface
separation, transient sensory afferent input & reduction in perception of pain
Joint surface separation will commonly result in intra-articular cavitation, commonly accompanied with
audible pop.
Post manipulation reductions in pain perception influenced by supraspinal mechanisms including
expectation of benefit
Schema
Popping sound: phenomenology & refractory period
WHAT IS POPPING SOUND?
Popping sound phenomenology
- Cavitation: audible popping sound caused by release of gas bubbles from synovial fluid when
joint rapidly stretched or adjusted
- Tribonucleation: formation of gas bubbles in joint due to rapid separation of surfaces, creating
low-pressure environment causing cavitation or popping sounds during adjustment
Refractory period
20min for MCP
68 min for Lx
Cracking sound does not occur until gas completely absorbed into joint
Is popping sound necessary: description, yes, no & clinical prediction rule
S POPPING SOUND NECESSARY?
- No consensus on association between audible pop & pain outcomes in SM
- Knowledge about audible pop phenomenon in SM has advanced.
- Review suggests that presence or absence of audible pop not significant in relation to pain
outcomes.
- RCTs conducted to test effectiveness of interventions that cannot be assessed using lesser
methods
- No meta-analysis or effect size available
o, it is not necessary
- 84% of subjects reported perceiving audible pop.
- No relationship observed between audible pop & pain, disability or ROM
- Pragmatic study results suggest perceived audible pop not correlate with improved outcomes in
high velocity thrust manipulation.
- No improvement in outcomes for patients with non-radicular LBP, either immediately or in longterm follow-up.
Clinical prediction rule:
- Duration of symptoms < 16 days
- Fear avoidance beliefs questionnaire < 19
- Hypomobility with lumbar spring testing
- At least 1 hip with > 35 IR ROM
- No symptoms distal to knee
Really not necessary?
- CPR (Clinical Prediction Rule) not perform better than chance in identifying patients with acute,
non-specific LBP likely to respond to spinal manipulation.
- CPR by Childs et al. not generalize to primary care patients with acute LBP receiving spinal
manipulation.
Evidence based medicine
Evidence based medicine
- Integrating clinical expertise with best available external evidence is essential, neither alone is
sufficient.
- EBM not “cookbook” medicine, requires bottom-up approach combining external evidence,
clinical expertise & patient preferences.
- Evidence can inform decisions but cannot replace individual clinical expertise.
Patient perspective
Patient’s perspective
- Participants in study reported belief that popping was related to effectiveness of MT
- High percentage of sample had beliefs about spinal manipulation mechanisms for audible
popping sound that were inconsistent with current literature
- Instructions given by MT practitioners did not seem to be influence on patients’ beliefs
PT perspective
Physiotherapists’ perspective
- SM considered to have been successfully performed: “when multiple popping sounds elicited” (n
= 285, 49.6%), & “when single popping sound heard” (n = 170, 29.6%). “no popping sound” (n =
54, 9.4%)
- Three hundred seventy-six participants (65.4%) did not consider popping sound as necessary.
Evidence based practice
Evidence based practice
- If practice & no popping sound → think you’re not effective
TVA,e
When deliver SM: clinical prediction rules & implications
WHEN DELIVER SPINAL MANIPULATION?
Clinical prediction rules
- Clinical tools quantify contribution of history, physical examination & basic lab results to
diagnosis, prognosis, or treatment response for individual patients.
- Development of a Clinical Prediction Rule (CPR) follows a hierarchical process:
o Derivation phase
o Validation phase (assessing rule’s performance and generalizability)
o Clinical impact analysis (evaluating influence on clinical outcomes)
- Rigorously validated CPRs, shown to produce beneficial outcomes, can be confidently
incorporated into clinical practice.
- None of the 25 CPRs for physical therapy management of LBP ready for clinical use.
Diagnostic CPRs for LBP are still in initial development phase & cannot be recommended for
clinical practice yet.
- Most CPRs have not undergone proper validation, so they should only be used cautiously to
inform prognostic clinical judgments.
- It is unclear whether clinical application of these tools will result in improved patient outcomes or
greater resource efficiency.
Implications
Possibilities highlight why validation studies are so important: risk of making flawed treatment decisions
increases when we base clinical judgments on derivation-level studies
Understanding how our treatments work: perhaps it is time to focus our attention on increasing our
understanding of mechanisms behind our treatments
When do SM: imaging & clinical criteria
Imaging
87.6% of subjects had one or more-disc bulges on MRI
73.3% male & 78% female in 20s
Frequency, number & disk displacement increase with age to 50s (peak 40s)
Clinical criteria
290 synonyms used to describe entity or lesion … But formal evidence of ability to detect & treat these
entities is lacking
Indications for manipulation are neither systematic nor specific. Use of manipulation for neck pain is at
best empirical. Most perform SM simply on basis of complaint NP
Various indication criteria referred in many studies are only clinical phenomena as none of these has been
shown to be poorly reliable & valid
Spinal palpatory diagnostic procedures (Spring test) unreliable
Move from accessory mob / testing to provocative test because 1st thing you treat => pain
SM specific: description & clinical implications
S SPINAL MANIPULATION SPECIFIC?
- Specific technique used in spinal manipulation is unlikely to be critical for immediate responses.
- Reduction in atlantoaxial rotation asymmetry occurred regardless of whether HVLA (high-velocity,
low-amplitude) manipulation applied.
- Site of manipulation & thrust direction may not be clinically important.
- Effect of directing manipulation at most painful lumbar level compared to generic manipulation
on pain intensity was too small to be considered clinically significant.
- No clinically important differences found between directed & generic manipulation for individuals
with LBP.
Clinical implications
Pain modulation may not be limited to mechanisms associated with manipulation of putative motion
restrictions & immediate palliative effects may not require specificity
Effects of SM depend on its application side: PPTs were significantly increased immediately after
SM at most sensitive segment (vs stiffness)
Biomechanics
Biomechanic
Science dealing with external & internal forces acting on biological
systems & associated effects produced by these forces
Pre-thrust mid-range position
Mean pre-thrust rotation position was 30-54°
Mean pre-thrust lateral bending position was 46°
Kinematic & kinetic of SM
Kinematic & kinetic
Components are applied at level to be manipulated only
Spinal level did not influence total 3D ROM & angular displacement
Thus, you don’t rotate or lateral flex “down to” level
=> this is not necessary!
Rotation compensates by SB
1. Rotation away
2. Lateral shift
3. Side bend toward
4. PA shift
Axial rotation & lateral bending were positively correlated
Rotation & lateral bending were always of opposite direction
Barriers of SM
Barriers
Barrier = tension point through with it is applied impulse to elicit popping sound phenomenon during
HVLA thrust manipulation delivery
Segmental barrier: actual available limit of tension. Depends by pain and/or other intra/extra-articular
factors
Osteo-ligamentous barrier: tension point through which single articulation reach physiologic / anatomical
limit
Mid-range barrier: combination of multiple physiologic & accessory movements allows to engage
movement limit before end-range of single component
End-range barrier
Single lever barrier: coincides with end-range of single physiologic
movement in order to engage osteo-ligamentous barrier
Mid-range barrier
Multi lever barrier: combination of multiple levers moves away tension
point from end-range taking it to mid-range of single component
3D kinematic & kinetic
3 D kinematic & kinetic
- Peak rotation & peak lateral bending occurred simultaneously: this instant was defined as that of
thrust
- Took mean of 7 sec from contact/the start of movement of head to moment of thrust
- Constructive fiddling or setting up optimal barrier/components & priming takes few seconds
Mid range thrust
Mid-range thrust
- Except for lateral bending, close to active range, motion ranges obtained during HVLA
manipulation were well below active rom reported in literature
- Amplitude for rotation, generally assumed to involve greatest risks for negative side effects, is
significantly lower than during active motion
Momentum induced technique
Momentum induced technique
Mean de-rotation displacement 4.8 degrees
De-rotation displacement is significantly correlated with thrust displacement, thrust velocity & peak
thrust acceleration
Thrust duration
Thrust duration
Mean duration of a single thrust
- 96.95 ms [dunning et al., 2013]
- 135 ms [triano, 1992]
- 80-100 ms [herzog et al., 1993]
- 158 ms [ngan et al., 2005]
Less than muscle’s physiological reaction time <250|360 ms
Biomechanical effects of manipulation completed prior to any protective muscular response that might
develop
Impulse velocity
Impulse velocity
Peak thrust velocity: 127°sec
Mean thrust velocity: 72°sec
Mean peak acceleration of thrust: 2183°sec
Force
Peak and preload forces varied dramatically depending on the location of treatment application,
practitioners’ gender and experience
F = m x a
Lever
Less force & faster speeds needed for effective delivery
Force for cervical manipulation
Force for cervical manipulation
Mean peak force: 118 n (+/- 16 n)
mean duration of force: 102 ms (+/- 15 ms) time to peak force: 48 ms (+/- 15 ms)
Cervical manipulation is less forceful and inherently faster than manipulation used elsewhere
Force for Tx manipulation
Force for thoracic manipulation
Preload mean force (mean force observed during the 500 ms preceding the treatment thrust) = 24 n
Mean (global) peak force = 238 n, but local peaks over 25 mm sq. Area only 5 n average rate of force
application was 1368 n/s
Preload force showed decrease just before the thrust and reaches peak in 150-200 ms
Total forces from pre-load to peak force increased by a factor of 10!
Thrust displacement & direction
Thrust displacement
What is amplitude of actual thrust?
Mean thrust displacement 13 degrees
Mean thrust displacement / angle: 11.4 degrees (range: 6.0-22.5 degrees)
Displacement direction:
- Not intentional
- Not predictable
- Not reproducible
Mob vs manip
MOB vs MANIP
- Terms ‘manipulation’ & ‘mobilization’ often interchanged or used to describe same technique.
- Grade V sometimes questioned as natural progression from grades I-IV.
- Grade V typically defined as manipulation.
- Multiple repetitive oscillations vs. single thrust lead to audible pop or cavitation.
- High-velocity thrusts differ from slow repetitive motions in technique.
- Duration of a manipulation is typically around 90-200 ms.
- Both manipulation & mobilization have neurophysiological effects.
Cervical popping sound
Cervical popping sound
- Cavitation was significantly more likely to occur bilaterally (91.9%)
- Traditional approach of targeting single ipsilateral or contralateral facet joint in upper cervical
spine may not be realistic
- More likely to occur unilaterally, & on side contralateral to short-lever applicator contact
- Accurate about more half of time
- Most manipulation produced 2-6 pops
- 3.5 cm far from target
Lx popping sound
Lumbar popping sound
- Mean number of 5.27 pops
- More likely to occur bilateral with no side prevalence
- Accurate about half of time
- 63.5% manipulation produced 2-6 “pops”
- Average error from target joint 5.29 cm
Clinical implications of popping sound accurate & specific to target joint
Clinical implications
Average discrepancy error was one level away from target vertebrae when cavitate 4 or more joints, have
high likelihood of cavitating target joint
Conclusion on popping sound
POPPING SOUNDS
- 1
st study to use time-frequency analysis to investigate audible pops during HVLA thrust
manipulation.
- Remains unknown whether multiple popping sounds originate from same joint or from adjacent
ipsilateral or contralateral facet joints.
- Single model may not be able to explain all the audible sounds produced during HVLA thrust
manipulation.
- Due to presence of multi-peak energy bursts & sounds at multiple frequencies, cavitation
hypothesis alone cannot fully explain all audible sounds during HVLA manipulation.
- Possibility that multiple phenomena occurring simultaneously during manipulation
