The Effect of Experimental Neck Pain in Healthy Participants

Study Overview
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Brief Summary
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This study investigates if/how an experimentally applied muscle pain/soreness, lasting for some days may affect brain activity, balance, movement patterns, muscle function and pain sensitivity in a healthy population

Detailed Description
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All included healthy volunteers will participate in test-sessions on 4 separate days over approximately 2 weeks. During the study participants will be randomised into and either a control group (injection of isotonic saline into a neck muscle) or neck pain group (injection of Nerve Growth Factor (NGF) into a neck muscle). Alle participants tested with regards to: Brain activity related to neck muscles will be estimated using TMS Balance will be tested using a force place Body movements will be recorded using 3D tracking Muscle activity will be estimated using electromyography (EMG)

Official Title
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The Effect of Experimental Neck Pain in Healthy Participants - The Transition From Acute to Ongoing Pain

Conditions
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Healthy, Neck Pain

Intervention / Treatment
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* Other: Injection of Isotonic saline
* Other: Injection of NGF


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy men and women aged 18-50 years Only for sub-projects 1 and 2: Right-handed Able to speak, read and understand Danish and English Exclusion Criteria: Pain from the neck or shoulder area during the past 6 months Experience of delayed onset muscle soreness (DOMS) during the week leading up to the test session Former surgery in neck or shoulder Current or previous chronic or recurrent pain condition Pregnancy Drug addiction defined as the use of cannabis, opioids or other drugs Previous neurologic, musculoskeletal or mental illnesses Regular use of analgesics Abnormally disrupted sleep in the last 24 hours preceding the experiment Lack of ability to cooperate Unable to pass the TASS safety screening questionnaire for TMS

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Control group<br>Participants will be injected with 0.5ml Isotonic saline into a neck muscle | Other: Injection of Isotonic saline<br>* Half the participants will be injected in a neck muscle with isotonic saline (Control group) and the other half will get NGF (Neck pain group).<br>|
| Experimental: Neck pain<br>Participants will be injected with 0.5ml NGF into the a neck muscle | Other: Injection of NGF<br>* Half the participants will be injected in a neck muscle with NGF (Neck pain group).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pressure pain threshold (PPT) measured with a handheld pressure algometer | PPT will be assessed over head, neck, arm and leg sites. | Day 0, 2,4 and 15 | 
| Change in motor evoked potentials | Trans cranial magnetic stimulation (TMS) is used to asses motor evoked potentials of neck muscles | Day 0, 4 and 15 | 
| Change in Body movement | 3D recordings of body movements | Day 0, 4 and 15 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in muscle activity (EMG) | EMG of axioscapular muscles & trunk during arm movements | Day 0, 4 and 15 | 
| Change in standing balance | Standing balance is measured on a force platform | Day 0, 4 and 15 | 
| Change in perceived pain: McGill Pain Questionnaire | Pain will be scored using a scale from 0-10 with 0 being no pain and 10 being worst imaginable pain, by drawing on body charts and choosing words from the McGill Pain Questionnaire. | Day 0, 2,4 and 15 | 
| Disability | Neck disability Index will be scored. Body movements will be scored on a modified 6-point Likert scale (0 = not difficult at all; 1 = minimally difficult; 2 = somewhat difficult; 3 = fairly difficult; 4 = very difficult; 5 = unable to perform) | Day 0, 2,4 and 15 | 
| Pain Catastrophizing Scale (13 item questionnaire) | Pain Catastrophizing Scale (PCS) questionnaire. 13 items that can be answered with a Likert scale (0 = not at all, 1 = to a slight degree, 2= to a moderate degree, 3 = to a great degree, 4 = all the time). The PCS is scored by summing responses to all 13 items with scores ranging from 0 - 52. | Day 2 | 
| The Big Five Inventory (BFI) | BFI questionnaire investigates five general traits personality: extraversion, agreeableness, conscientiousness, neuroticism and openness. The BFI consists of 44 items that are answered on a 5 point Likert scale (1=Disagree strongly, 2=Disagree a little, 3=Neither agree or disagree, 4=Agree a little, 5=Agree strongly). This is not good/bad score in this questionnaire as it only assess personality traits. | Day 2 |