Neurophysiologic Effects of Cervical Spinal Manipulation in Asymptomatic Individuals

Study Overview
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Brief Summary
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This study had the goal of analyse the neurophysiologic effects of both mechanical and manual cervical manipulation, in asymptomatic individuals.

Detailed Description
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In this study, the investigators compared the effects of manual manipulation and instrument assisted manipulation of C3/C4 on muscle tone, elasticity and stiffness and on pressure pain threshold , and pressure pain perception. The muscles evaluated were upper trapezius and biceps brachialis, bilaterally. The study also had a placebo and a control group. All individuals were asymptomatic.

Official Title
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Neurophysiologic Effects of Cervical Spinal Manipulation in Asymptomatic Individuals

Conditions
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Healthy Subjects

Intervention / Treatment
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* Other: Cervical spine manual manipulation
* Other: Cervical spine mechanical manipulation
* Other: Placebo intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subjects. Minimum of 18 years old. Exclusion Criteria: Pain in cervical region, shoulders or arms. History of trauma or disease in the cervical region or upper limb. Use of medication that could affect the outcomes (painkillers, NSAID, or anti depressives) during the last week.

Ages Eligible for Study
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Minimum Age: 18 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: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Manual manipulation<br>In the Manual manipulation group, the thrust was applied in the right side of C3/C4 with neutral flexion/extension, ipsilateral side bending and contralateral rotation. Then, a low amplitude, high velocity thrust in rotation was delivered. | Other: Cervical spine manual manipulation<br>* In the Manual manipulation group, the thrust was applied in the right side of C3/C4 with neutral flexion/extension, ipsilateral side bending and contralateral rotation. Then, a low amplitude, high velocity thrust in rotation was delivered.<br>|
| Active Comparator: Mechanical manipulation<br>In the Mechanical manipulation group, the Activator instrument was applied on the right transverse apophyses of C3. | Other: Cervical spine mechanical manipulation<br>* In the Mechanical manipulation group, the Activator instrument was applied on the right transverse apophyses of C3.<br>|
| Placebo Comparator: Placebo<br>The subjects were positioned in the same pre-manipulative position as the manual manipulation group, but the thrust didn't occur. Instead, the position was hold for 3 seconds and then the subject's head returned passively to neutral position. | Other: Placebo intervention<br>* The subjects were positioned in the same pre-manipulative position as the manual manipulation group, but the thrust didn't occur. Instead, the position was hold for 3 seconds and then the subject's head returned passively to neutral position.<br>|
| No Intervention: Control<br>The subjects stayed in supine position and no intervention occurred. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pressure pain thresholds | To measure the pressure pain threshold, it was used an electronic pressure dynamometer FORCE ONE™ FDIX (Wagner Instruments - Greenwich, USA), with 1cm2 of surface. The values were expressed in Kg/cm2. The pressure was increased at a rate of 1 kg/cm2/s until the subject inform that the sense of pressure has become a sense of pain. | Immediately after the intervention | 
| Pressure pain perception | To evaluate the pressure pain perception, it was used a Visual Analogue Scale (VAS). The pressure increased until 2,5 kg/cm2 and was hold for 5 seconds, and the subject used the VAS scale to record the pressure pain perception he felt. | Immediately after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle tone | To measure muscle tone it was used the MyotonPro device. It was used to evaluate those parameters both on the biceps and on the upper trapezius, bilaterally. The device was located perpendicular to the middle point of each muscle and it were recorded 6 impulses in each one of them. The non-neural tone was recorded as frequency. | Immediately after the intervention | 
| Muscle stiffness | To measure muscle stiffness it was used the MyotonPro device. It was used to evaluate this parameter both on the biceps and on the upper trapezius, bilaterally. The device was located perpendicular to the middle point of each muscle and it were recorded 6 impulses in each one of them. The muscle stiffness was recorded as N/m. | Immediately after the intervention | 
| Muscle elasticity | To measure muscle elasticity it was used the MyotonPro device. It was used to evaluate those parameters both on the biceps and on the upper trapezius, bilaterally. The device was located perpendicular to the middle point of each muscle and it were recorded 6 impulses in each one of them. The elasticity was indicated by logarithmic decrement. | Immediately after the intervention |