The Effect of a Single Spinal Manipulation on Cardiovascular Autonomic Activity

Study Overview
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Brief Summary
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This study evaluates the effect of a single high-velocity low-amplitude spinal manipulation on both cardiovascular autonomic activity and pressure pain thresholds. It is a cross-over study, thus each participant will undergo both interventions (spinal manipulation and sham manipulation). Both interventions will be separated by a 48 h wash-out period.

Detailed Description
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Several systematic reviews have shown that spinal manipulations may have an immediate effect on autonomic nervous system activity (e.g. increase in skin sympathetic nerve activity) and on sensitivity to experimentally-induced pain (e.g. increase in pressure pain threshold). It is generally unknown i) if these supposed effects last after the immediate post intervention period and ii) if there is a statistical relationship between them, considering that pain and autonomic networks are closely connected and interact at the peripheral, spinal and supra-spinal levels. The primary aim of the study is to assess every single effect immediatly and at short-term after the intervention. The secondary aim is to assess the bivariate statistical relationship between cardiovascular autonomic activity and sensitivity to experimentally-induced pain after the intervention. Cardiovascular autonomic nervous system activity is assessed with both heart rate and systolic blood variabilities Sensitivity to experimentally-induced pain is measured using pressure pain threshold.

Official Title
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The Effect of a Single Spinal Manipulation on Cardiovascular Autonomic Activity in Healthy Subjects: a Randomized, Cross-over, Sham-controlled Trial

Conditions
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Manipulation, Spinal

Intervention / Treatment
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* Other: High velocity low amplitude manipulation
* Other: Sham manipulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: First-year chiropractic student at IFEC Volunteer Healthy (no pain, no disease) Exclusion Criteria: Counter indications to spinal manipulation Drugs intakes (pain killers or beta-blockers) Food, Caffeine and tobacco intakes during the previous hour Alcohol intake and performance of strenuous physical activity the day of the experimentation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High velocity low amplitude manipulation<br> | Other: High velocity low amplitude manipulation<br>* The researcher manually applies a preload force on the T5/T6 level followed by a single posterior to anterior thrust.<br>|
| Sham Comparator: Sham manipulation<br> | Other: Sham manipulation<br>* The researcher manually applies a preload force on the right scapula followed by a single lateral thrust.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate variability (HRV) | Frequency and Time-domain analyses of HRV from 5-minutes ECG recording | Baseline, + 5 minutes, + 15 minutes, + 30 minutes | 
| Local (T5) and distal (L4) Pressure pain thresholds (PPT) | The mean of 3 successives PPT in kilopascal | Baseline, immediatly after intervention, + 12 minutes, + 25 minutes, + 35 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic blood pressure variability | Frequency analysis in the low frequency band of systolic blood pressure variability from 5-minutes recording | Baseline, + 5 minutes, + 15 minutes, + 30 minutes |