Impact of a Multimodal Physiotherapy Program in Fighter Pilots With Flight-related Neck Pain

Study Overview
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Brief Summary
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The aim of this study was to analyse the immediate effects of a 4-week multimodal physiotherapy program which combines cervical supervised exercises with laser-guided feedback (ELGF) and interferential current electro massage (ICE) in fighter pilots with flight-related neck pain.

Detailed Description
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Flight-related neck pain constitutes a clinical entity related to the performance and flight safety of fighter pilots. The aim of this study was to analyse the effectiveness of a multimodal physiotherapy program which combines supervised Exercise with Laser-Guided Feedback (ELGF) and Interferential Current Electro-Massage (ICE) in fighter pilots with flight-related neck pain. 31 pilots were randomly allocated into two groups (Experimental Group n=14; Control Group n = 17). The intervention consisted of 8 sessions (twice a week) for 4 weeks. As primary outcome measures the following variables were measured: perceived pain intensity (Numeric Pain Rating Scale) and neck disability (Neck Disability Index). The secondary outcome measures were: cervical range of movement (CRoM), joint position sense error (JPSE) and pressure pain threshold (PPT).

Official Title
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Impact of a Multimodal Physiotherapy Program in Fighter Pilots With Flight-related Neck Pain

Conditions
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Neck Pain

Intervention / Treatment
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* Other: Cervical supervised exercises with laser-guided feedback (ELGF)
* Other: Interferential current electro massage (ICE)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Flight pilots (male and female) who, at the time of the assessment, were an instructor or student attached to the 23th Wing of Talavera Air Base, Spanish Air Force (SAF), Badajoz. Flight pilots diagnosed with flight-related neck pain according to the International Classification proposed by an expert panel of the North Atlantic Treaty Organisation (NATO). A minimum perceived pain of 3/10 on the Visual Analogue Scale (VAS) in the early-morning assessment. Scores of ≥5 points on the Neck Disability Index (NDI), and a cervical-repositioning error of ≥4.5°. Exclusion Criteria: Cervical pain with radiation to the upper limbs and/or radiculopathy. Cervical spine surgery with or without the presence of a metal implant. Having received physiotherapy or any other routine medical care six weeks prior to data collection. Being involved in ongoing medical-legal conflicts.

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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No

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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control group<br>Participants in the control group will not receive any intervention and will continue with their normal combat and flight exercise activities. They will be asked not to take medication or seek alternative treatments. | |
| Experimental: Experimental group<br>Participants in the experimental group will follow a supervised ELGF program. Subsequently, they will receive an intervention based on manual therapy combined with electrical stimulation called electro-massage. | Other: Cervical supervised exercises with laser-guided feedback (ELGF)<br>* Cervical supervised exercises with laser-guided feedback (ELGF) is defined as a procedure of proprioceptive training based on a type of therapeutic exercise that provides external feedback to exercise, achieving an improvement in range of motion and postural control in subjects with spinal pain. For the performance of the exercise program, Motion Guidance Clinician Kit (Motion Guidance LLC, Denver, CO, USA.) was used. The program consisted of 4 exercises, which progressed in difficulty according to the tolerance achieved over the course of the sessions: a) Maintaining the head position (cervical stabilisation); b) Cervical flexion-extension; c) Right-left rotations; d) Right-left lateral-flexions. Each exercise consisted of 4 series of 8 repetitions, except the first one, in which the head position is maintained by pointing the laser at the centre of the panel for 30 seconds (4 series). The average time to complete the entire program did not exceed 14 minutes.<br>Other: Interferential current electro massage (ICE)<br>* Interferential current electro-massage (ICE) is defined as a technique which combines simultaneously manual therapy (massage) and ICT. We used a current bipolar mode, using a carrier frequency of 4000 Hz at constant voltage and an amplitude-modulated frequency of 100 Hz (Sonopuls 692®; Enraf-Nonius BV, Rotterdam, The Netherlands), was administered. The intensity was set to provide a strong and comfortable tingling, without evoking muscle twitches even though a slight vibration (fasciculation) was allowed. The sequence combined (A) superficial stroke over the neck-shoulder for 30-45 seconds; (B) deep sliding movements, alone or (C) combined with shoulder drop, for 4-5 minutes; (D) bilateral kneading of the upper trapezius (4-5 minutes); (E) slight stretching of cervical muscles (upper trapezius, sternocleidomastoid, and levator scapulae); and repetition of step (A). The electro-massage protocol lasted 15 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neck Disability Index (NDI) | The degree of cervical disability involvement was measured through the Neck Disability Index (NDI), translated into Spanish, presenting optimum reliability and internal validity. It consists of 10 sections, 4 of them are related to subjective symptoms and the other 6 are related to basic activities of daily life. Each of the sections presents 6 possible responses, scoring these from 0 to 5 according to progression of functional disability. Scores less than 5 points indicate non-disability, between 5-14 points indicates mild disability, values between 30-48 points moderate disability, between 50-64 points severe disability and those that exceed 70 points represent complete disability. | 4 weeks. | 
| Numeric Pain Rating Scale (NPRS) | Numeric Pain Rating Scale (NPRS) is a 11-point numeric rating scale, where 0 denotes no pain and 10 denotes the maximum bearable pain. The minimum clinically important difference (MCID) for this tool has been established at 1.5 points and the minimum detectable change (MDC) at 2.6 points, in individuals with neck pain. The NPRS is a valid scale with moderate test-retest reliability in this population (Intraclass Coefficient Correlation (ICC): 0.76, 95% CI 0.58 to 0.93). | 4 weeks. | 
| Root Mean Square of the Successive Differences (RMSSD) | It indicates the degree of activation of the Parasympathetic Nervous System on the cardiovascular system. It is obtained from the square root of the mean value of the sum of the squared differences of all successive RR intervals. This parameter reports the short-term variations of the RR intervals. It is directly associated with short-term variability. | 4 weeks. | 
| Stress Score | It is an index described by Naranjo-Orellana et al. to facilitate physiological interpretation of Poincaré plot. It is expressed as the inverse of the SD2 diameter multiplied by 1000 and is considered directly proportional to the sympathetic activity in the sinus node. | 4 weeks. | 
| Sympathetic/parasympathetic ratio (S/PS) | It is also described by Naranjo-Orellana et al., S/PS is expressed as the quotient of SS and SD1, and it is considered to reflect autonomic balance - that is, the relationship between sympathetic and parasympathetic activity | 4 weeks. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cervical Range of Motion (CRoM) | For the evaluation of CROM, a conventional EnrafNonius® two-branch goniometer was used. Subjects were placed in a seated position on a stool, with a neutral neck and head position. The range of active cervical mobility presented by the patients was measured in reference to the three planes of the space. In the sagittal plane, the degrees of mobility to flexion and extension were measured, in the frontal plane the right and left inclinations, and in the transverse plane both rotations. | 4 weeks. | 
| Cervical Joint Position Sense Error (JPSE) | This test consists of a visual measurement of the error in moving the head to the initial neutral position after active cervical rotation. | 4 weeks. | 
| Pressure Pain Threshold (PPT) | A mechanical pressure Fisher algometer (Force Dial model FDK 40) with a 1 cm² area contact head was used to measure the pressure pain threshold. The reliability of pressure algometry has been found to be high [intraclass correlation coefficient = 0.91 (95% confidence interval, 0.82-0.97)]. With the participant in supine, the pressure pain threshold of the the myofascial trigger point nº2 of the upper trapezius muscle according to Travell and Simons and the central trigger point of the sternocleidomastoid muscle was bilaterally evaluated. Also, in sitting position the pressure pain threshold of the myofascial trigger point of the scapula elevator muscle was bilaterally evaluated. The minimal clinically important difference (MCDI) is 1.2 Kg/cm2. | 4 weeks. | 
| Standard Deviation 1 (SD1) | It indicates the sensitivity of short-term variability in HRV non-linear spectrum. It is considered an indicator of parasympathetic activity. | 4 weeks. | 
| Standard Deviation 2 (SD2) | It is a diameter from Poincaré plot which indicates the degree of longitudinal dispersion. It is thought to reflect long-term changes in RR intervals and it is considered an inverse indicator of parasympathetic activity. | 4 weeks. | 
| Min_HR | Minimum heart rate variability. | 4 weeks. | 
| Max_HR | Maximum heart rate variability. | 4 weeks. | 
| Mean_HR | It corresponds to the interval between two beats (R peaks on the ECG). | 4 weeks. | 
| pNN50 | Percentage of consecutive RR intervals that differ by more than 50 ms from each other. A high value of pNN50 provides valuable information about high spontaneous HR. | 4 weeks. | 
| Low Frequency Power (LF) | Situated between 0.04 and 0.15 Hz. In long-term recordings it provides us with more information about the activity of the SNS. | 4 weeks. | 
| High Frequency Power (HF) | They are located between 0.15 and 0.4 Hz. HF is clearly related to PNS activity and has a relaxation-related effect on HR2. | 4 weeks. | 
| Low/High Frequency ratio (HF/LF) | From low frequency and high frequency ratio of the HRV spectral analysis result we can estimate the vagal (related to relaxation and HF) and sympathetic (related to stress and LF) influence. Thus we can estimate sympathetic-vagal balance. | 4 weeks. | 
| Myoelectric activity | The electromyography (EMG) signal of the upper trapezius muscle was recorded during 3 step contractions of shoulder elevation force (15%-30% maximal voluntary contraction). The highest value of the three contractions was taken. The signal of the sternocleidomastoid muscle was recorded during 3 billateraly step contractions of neck flexión and antepulsion neck force. Both contractions were performed in a combined and simultaneous movement, recreating the movement produced by the reaction forces in the takeoff and landing of the fighter jet. Both movements were made at 15%-30% maximal voluntary contraction, as used by Calamita et al on the same musculature in subjects with nonspecific neck pain. | 4 weeks. | 
| Kinesophobia | The Spanish version of the TSK-11 was used to measure fear of movement. Higher scores indicate greater fear-avoidance behaviors. The TSK-11 has demonstrated acceptable internal consistency and validity. | 4 weeks. | 
| Catastrophizing Pain | The Pain Catastrophizing Scale (PCS) is a self-administered scale of 13 items and one of the most used to assess catastrophism of pain. The subjects take their past painful experiences as a reference and indicate the degree to which they experienced each of the 13 thoughts or feelings on a 5-point Líkert scale ranging from 0 (never) to 4 (always). The theoretical range of the instrument is between 13 and 62, indicating low scores, little catastrophism, and high values, high catastrophism. | 4 weeks. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fighter pilots, flight-related neck pain, disability, electric massage, Therapeutic exercise