Effectiveness of a Quick Release Dynamic Muscle-strengthening Program on Dynamic Stabilization of the Cervical Spine

Summary

The goal of this clinical trial is to learn if Quick Release dynamic strengthening of the cervical spine extensor muscles' reflex could improve dynamic stabilisation capacities of the cervical spine by reducing muscle activation delay in amateurs rugby players. The main questions it aims to answer are described as follows:

The primary outcome measure is the comparison between the intervention and control groups of the variation in activation delay of the cervical spine extensor muscles in milliseconds (ms) between the beginning and the end of the strengthening program. The activation delay in milliseconds corresponds to the time between the onset of impact application on the head and the onset of reactive muscle force production measured by the Cervistab© ergometer.

The secondary outcomes are also a comparison between the two groups of the variations from the beginning to the end of the strengthening program for the followings parameters, measured during with the Cervistab© machine:

* Reflex Force Production Rate (N/ms): slope of the force/time graph.
* Maximum Reactive Force (N): maximum force value produced within 300 ms following impact.
* In both intervention groups: measurement of the variation in head displacement (in mm) during quick release strengthening protocol.
* In each subgroup, 10 participants will be equipped with Instrumented Mouthguards. Researchers will compare the variation in workload measured by these mouthguards during Cervistab evaluations conducted before and after the training protocol.

Researchers will compare the intervention group to a distractor (control) arm to see if our training protocol has an impact on the activation delay.

Conditions

• Rugby
• Craniocerebral Trauma
• Cervical Spine Injury
• Stabilization

Interventions

OTHER

isometric contractions

Participants will perform 20 minutes of isometric contractions in different positions, with contraction durations of 10 seconds and a number of repetitions between 4 and 10, depending on their progress in the training program.

OTHER

stroboscopic glasses

This training involves performing skill exercises with a rugby ball while wearing stroboscopic glasses. The glasses have alternating opaque and clear sections, causing multiple and/or fragmented vision. The goal is to improve the processing of visual information at the level of higher functions. This aids in decision-making. It does not involve the same structures and functions implicated in reflexive muscle recruitment strategies as the Quick Release, so it should not be a confounding factor. However, it provides a beneficial, stimulating, and enjoyable training session, increasing subject adherence as they work on a skill useful in their sport.

OTHER

Quick Release

The distance (in mm) of the anterior head translation will be measured using a linear displacement sensor. The subject will be instructed to recruit their extensor muscles as quickly and as strongly as possible to minimise the head displacement distance. They will be aware of their score after each repetition (real-time feedback). Subjects must react to a rapid forward displacement of the cervical spine, without impact. To generate this forward displacement without impact, subjects are positioned with support in front of the forehead, holding their head and neck. The subject must exert an isometric flexion effort against this frontal support (energy storage), with the intensity set by the examiner based on the Maximum Isometric Force measured during a prior maximal isometric test. The frontal resistance will suddenly release, and the head displacement in the sagittal plane will be measured until the recruitment of the cervical spine extensor muscles stops this displacement

Sponsors & Collaborators

• Université Montpellier

  collaborator OTHER

• University Hospital, Montpellier

  lead OTHER

Principal Investigators

• Marc Julia, MD · University Hospital, Montpellier

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-08-05

Primary Completion

2025-05-05

Completion

2025-05-05

Countries

• France

Study Locations