Pain Inhibitory Effects of a Single Painful Mechanical Stimulus Compared to Multiple and Multiple at Different Locations

Study Overview
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Brief Summary
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The objective is to estimate the effects on pain thresholds of a single painful mechanical stimulus compared to multiple and multiple stimuli at different locations.

Detailed Description
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The mechanical stimulus produced in manual therapy (MT) techniques elicits neurophysiological responses within the peripheral and central nervous system responsible for pain inhibition. Almost all types of MT elicit a neurophysiological response that is associated with the descending pain modulation circuit. But it has not been demonstrated whether this inhibition occurs through a conditioned pain modulation mechanism induced by painful mechanical stimulation that is carried out with manual therapy techniques.

Official Title
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Conditioned Pain Modulation Induced by Mechanical Stimulation: A Mechanism of Manual Therapy Analgesia - Study 3

Conditions
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Healthy

Intervention / Treatment
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* Other: Mechanical Conditioning stimulus


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy male or female between 18 and 65 years Free of pain and with no history of chronic pain Exclusion Criteria: Pregnant or having given birth within the last year

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Mechanical stimulation<br>Mechanical compression is applied with the thumb to the upper trapezius muscle on the non-dominant side at the midpoint between the acromion and C7. The intensity of this will be regulated by the pain it causes the patient, trying to ensure that it is at all times approximately 5/10 on the numerical pain rating scale (NPRS) with 0 being no pain at all and 10 being the worst pain imaginable. The stimulation will be carried out for 2 minutes. | Other: Mechanical Conditioning stimulus<br>* Painful mechanical stimulus<br>|
| Active Comparator: Repeated mechanical stimulation<br>Mechanical compression is applied with the thumb to the upper trapezius muscle on the non-dominant side at the midpoint between the acromion and C7. The intensity of this will be regulated by the pain it causes the patient, trying to ensure that it is at all times approximately 2/10 on the numerical pain rating scale (NPRS) with 0 being no pain at all and 10 being the worst pain imaginable. The stimulation will be performed for 2 minutes 4 times with 1 minute rest. | Other: Mechanical Conditioning stimulus<br>* Painful mechanical stimulus<br>|
| Active Comparator: Repeated mechanical stimulation at different locations<br>Mechanical compression is applied with the thumb. The intensity of this will be regulated by the pain it causes the patient, trying to ensure that it is at all times approximately 2/10 on the numerical pain rating scale (NPRS) with 0 being no pain at all and 10 being the worst pain imaginable. Stimulation will be performed for 2 minutes, 4 times, at four different sites (left and right upper trapezius and left and right lumbar paravertebral) with 1 minute of rest. | Other: Mechanical Conditioning stimulus<br>* Painful mechanical stimulus<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline in Tibialis Anterior Pressure Pain Threshold (PPT) to immediate post-conditioning stimulus | PPTs will be assessed on the dominant side over the tibialis anterior muscle using a digital algometer (Wagner instruments, Greenwich, CT, USA). Participants will be instructed to say stop when the pressure sensation becomes painful. The average of 3 assessments on the tibialis anterior of the dominant side will be performed for analysis. The algometer pressure for assessment will be gradually increased at a rate of 1kg/second. Data will be collected in kg/cm2. | At baseline and immediately after the conditioning stimulus | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Conditioned Pain Modulation, Manual Therapy, Physiotherapy, Physical therapy