Real-time Ultrasound Imaging as Feedback for Deep Cervical Extensors Activation

Study Overview
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Brief Summary
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The aim of this study will be to determine the value of adding real-time ultrasound imaging (RUSI) as an external feedback tool for teaching the contraction of the deep cervical extensors (DCE) in healthy subjects. The potential benefit of RUSI to facilitate activation of the DCE during a specific motor task as well as the retention capacity of this motor task after a short period of training will be investigated

Detailed Description
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Participants will be randomly allocated into two exercise groups: DCE exercise without RUSI feedback (DCE) and DCE exercise with RUSI feedback (DCE+RUSI). Participants assigned to DCE will perform an exercise known to selectively activate the semispinalis cervicis muscles. By the other hand, participants in the DCE+RUSI group will perform the same exercise as the DCE group to selectively activate the semispinalis cervicis muscle but receiving RUSI feedback about correct performance. In both groups, a total of 10 sets of 10 repetitions will be performed with one minute of rest between each set. Ultrasound measurement will be used to asses the antero-posterior dimension (thickness) of the DCE both at rest and during contraction at the level of C4 at baseline, immediately after the DCE exercise activation protocol and one-week follow-up in order to evaluate retention capacity. All participants will be asked to not perform any other cervical motor control exercise or exercise using RUSI feedback until the last time point assessment will be finished. All participants will be asked to avoid any exercises or treatments for neck pain between sessions. All ultrasound images will be analysed off-line using Image J software. Thickness and percent thickness change will be measured. The percent thickness change will be calculated by using the following equation: thickness contracted - thickness rest / thickness rest.

Official Title
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Real-time Ultrasound Imaging as Feedback for Deep Cervical Extensors Activation

Conditions
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Neck Disorder

Intervention / Treatment
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* Other: DCE without RUSI feedback
* Other: DCE + RUSI feedback about performance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No actual neck pain Being able to understand Spanish language Exclusion Criteria: Neck pain in the last 3 months Previous surgery in the neck region Neurological diseases or any other condition that may alter voluntary muscle contraction Previous experience with cervical motor control training exercises Previous experience using RUSI as an external feedback tool in any other body area

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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
Interventional Model Description: This will be a randomized clinical trial, with parallel groups and a blinded assessor performed in accordance with CONSORT guidelines. Participants will be randomized into two exercise groups: DCE exercise without RUSI feedback (DCE) and DCE exercise with RUSI feedback (DCE+RUSI). Randomization will be conducted using computer-generated random numbers (Epidat® version 3.1). Allocation concealment will be ensured using opaque and sealed envelopes
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: DCE group<br>DCE exercise without RUSI feedback | Other: DCE without RUSI feedback<br>* Participants assigned to this group will perform an exercise known to selectively activate the semispinalis cervicis muscle<br>|
| Experimental: DCE + RUSI group<br>DCE exercise with RUSI feedback | Other: DCE + RUSI feedback about performance<br>* Participants in this group will perform the same exercise as the DCE group to selectively activate the semispinalis cervicis muscle but receiving RUSI feedback about correct performance<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Deep cervical extensors function at baseline | Ultrasound measurements will be used to asses the antero-posterior dimension (thickness) of the deep cervical extensors both at rest and during contraction at the level of C4 | Baseline | 
| Change of the deep cervical extensors function from baseline to immediately after intervention | Ultrasound measurements will be used to asses the antero-posterior dimension (thickness) of the deep cervical extensors both at rest and during contraction at the level of C4 | From baseline to immediately after intervention | 
| Change of the deep cervical extensors function from baseline to one week after intervention | Ultrasound measurements will be used to asses the antero-posterior dimension (thickness) of the deep cervical extensors both at rest and during contraction at the level of C4 | From baseline to one week after intervention |