Results of neck-specific exercise for altered postural sway in individuals with chronic whiplash-associated disorders: a longitudinal case-control study.

Postural sway has not been investigated before or after a neck exercise intervention in individuals with chronic whiplash-associated disorders (WAD). The aim of the study was to investigate postural sway in individuals with chronic WAD grades 2 and 3: (a) compared with healthy matched controls at baseline; (b) after three months of neck-specific exercise and (c) to investigate the correlation between postural sway with self-reported dizziness during motion and balance problems/unsteadiness. This is a longitudinal prospective experimental case-control intervention study. Individuals with WAD (n = 30) and age- and gender-matched healthy volunteers (n = 30) participated. Postural sway was assessed using an iPhone application. Measurements were carried out at baseline, and for those with WAD a second measurement was performed at the three-month follow-up when neck-specific exercise intervention ended. The WAD group performed significantly worse than the healthy group in both pathway and ellipse area double stance eyes closed at baseline (main outcome), but not at the three-month follow-up. The WAD group significantly improved after rehabilitation in both pathway double stance eyes closed and pathway single stance eyes open. The correlation between postural sway and self-rated dizziness during motion and balance problems was low to moderate. One may conclude that postural sway was improved after a neck-specific exercise programme. The study results strengthen earlier findings that individuals with WAD have worse balance outcome when they have to rely on neck proprioception (eyes closed). The study results may be important for the development of improved rehabilitation methods for WAD.

The effect of a neck-specific exercise program on cervical kinesthesia for patients with chronic whiplash-associated disorders: a case-control study.

INTRODUCTION: Cervical kinesthesia is an important part of movement control and of great importance for daily function. Previous research on kinesthesia in whiplash-associated disorders (WAD) has focused on grades I-II. More research is needed on WAD grade III. The aim of this study was to investigate cervical kinesthesia in individuals with WAD grades II-III before and after a neck-specific exercise intervention and compare them to healthy controls. METHODS: A prospective, case-control study with a treatment arm (n = 30) and a healthy control arm (n = 30) was conducted in Sweden. The WAD group received a neck-specific exercise program for 12 weeks. The primary outcome to evaluate kinesthesia was neck movement control (the Fly test). Secondary outcomes were neck disability, dizziness and neck pain intensity before and after the Fly test. Outcomes were measured at baseline and post-treatment. The control arm underwent measurements at baseline except for the dizziness questionnaire. A linear mixed model was used to evaluate difference between groups (WAD and control) and over time, with difficulty level in the Fly test and gender as factors. RESULTS: Between-group analysis showed statistically significant differences in three out of five kinesthetic metrics (p = 0.002 to 0.008), but not for the WAD-group follow-up versus healthy control baseline measurements. Results showed significant improvements for the WAD-group over time for three out of five kinaesthesia metrics (p < 0.001 to 0.008) and for neck disability (p < 0.001) and pain (p = 0.005), but not for dizziness (p = 0.70). CONCLUSIONS: The exercise program shows promising results in improving kinesthesia and reducing neck pain and disability in the chronic WAD phase. Future research might benefit from focusing on adding kinesthetic exercises to the exercise protocol and evaluating its beneficial effects on dizziness or further improvement in kinesthesia. IMPACT STATEMENT: Kinesthesia can be improved in chronic WAD patients without the use of specific kinesthetic exercises. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03664934), first registration approved 11/09/2018.

Novel Internet Support for Neck-Specific Rehabilitation Improves Work-Related Outcomes to the Same Extent as Extensive Visits to a Physiotherapy Clinic in Individuals with Chronic Whiplash-Associated Disorders: A Prospective Randomised Study.

PURPOSE: To address the current lack of information about work-related factors for individuals with whiplash-associated disorders (WAD) we investigated the effectiveness of 3 months of neck-specific rehabilitation with internet support in combination with four physiotherapy visits (NSEIT) compared to the same exercises performed twice a week (24 times) at a physiotherapy clinic (NSE). METHODS: This is a prospective, multicentre, randomised controlled trial regarding secondary outcomes of work-related factors in 140 individuals with chronic moderate/severe WAD with 3- and 15-month follow-up. RESULTS: There were no group differences between NSE and NSEIT in the Work Ability Scale or work subscales of the Neck Disability Index, Whiplash Disability Questionnaire or Fear Avoidance Beliefs Questionnaire (FABQ-work). Both groups improved in all work-related outcome measures, except for FABQ-work after the 3-month intervention and results were maintained at the 15-month follow-up. CONCLUSIONS: Despite fewer physiotherapy visits for the NSEIT group, there were no group differences between NSEIT and NSE, with improvements in most work-related measures maintained at the 15-month follow-up. The results of the present study are promising for those with remaining work ability problems after a whiplash injury. Protocol registered before data collection started: clinicaltrials.gov NCT03022812.

Efficacy of Neck-Specific Exercise With Internet Support Versus Neck-Specific Exercise at a Physiotherapy Clinic in Chronic Whiplash-Associated Disorders: Multicenter Randomized Controlled Noninferiority Trial.

BACKGROUND: Neck-specific exercises (NSE) supervised by a physiotherapist twice a week for 12 weeks have shown good results in chronic whiplash-associated disorders (WADs), but the effect of exercise delivered via the internet is unknown. OBJECTIVE: This study examined whether NSE with internet support (NSEIT) and 4 physiotherapy sessions for 12 weeks were noninferior to the same exercises supervised by a physiotherapist twice a week for 12 weeks (NSE). METHODS: In this multicenter randomized controlled noninferiority trial with masked assessors, we recruited adults aged 18-63 years with chronic WAD grade II (ie, neck pain and clinical musculoskeletal signs) or III (ie, grade II plus neurological signs). Outcomes were measured at baseline and at 3- and 15-month follow-ups. The primary outcome was change in neck-related disability, measured with the Neck Disability Index (NDI; 0%-100%), with higher percentages indicating greater disability. Secondary outcomes were neck and arm pain intensity (Visual Analog Scale [VAS]), physical function (Whiplash Disability Questionnaire [WDQ] and Patient-Specific Functional Scale [PSFS]), health-related quality of life (EQ-5D-3L and EQ VAS), and self-rated recovery (Global Rating Scale [GRS]). The analyses were conducted on an intention-to-treat basis and with the per-protocol approach as sensitivity analyses. RESULTS: Between April 6, 2017, and September 15, 2020, 140 participants were randomly assigned to the NSEIT group (n=70) or the NSE group (n=70); 63 (90%) and 64 (91%), respectively, were followed up at 3 months, and 56 (80%) and 58 (83%), respectively, at 15 months. NSEIT demonstrated noninferiority to NSE in the primary outcome NDI, as the 1-sided 95% CI of the mean difference in change did not cross the specified noninferiority margin (7 percentage units). There were no significant between-group differences in change in NDI at the 3- or 15-month follow-up, with a mean difference of 1.4 (95% CI -2.5 to 5.3) and 0.9 (95% CI -3.6 to 5.3), respectively. In both groups, the NDI significantly decreased over time (NSEIT: mean change -10.1, 95% CI -13.7 to -6.5, effect size=1.33; NSE: mean change -9.3, 95% CI -12.8 to -5.7, effect size=1.19 at 15 months; P<.001). NSEIT was noninferior to NSE for most of the secondary outcomes except for neck pain intensity and EQ VAS, but post hoc analyses showed no differences between the groups. Similar results were seen in the per-protocol population. No serious adverse events were reported. CONCLUSIONS: NSEIT was noninferior to NSE in chronic WAD and required less physiotherapist time. NSEIT could be used as a treatment for patients with chronic WAD grades II and III. TRIAL REGISTRATION: ClinicalTrials.gov NCT03022812; https://clinicaltrials.gov/ct2/show/NCT03022812.

Fatty infiltrate and neck muscle volume in individuals with chronic whiplash associated disorders compared to healthy controls - a cross sectional case-control study.

BACKGROUND: The underlying pathophysiological mechanisms of chronic Whiplash Associated Disorders (WAD) are not fully understood. More knowledge of morphology is needed to better understand the disorder, improve diagnostics and treatments. The aim was to investigate dorsal neck muscle volume (MV) and muscle fat infiltration (MFI) in relation to self-reported neck disability among 30 participants with chronic WAD grade II-III compared to 30 matched healthy controls. METHODS: MV and MFI at spinal segments C4 through C7 in both sexes with mild- to moderate chronic WAD (n = 20), severe chronic WAD (n = 10), and age- and sex matched healthy controls (n = 30) was compared. Muscles: trapezius, splenius, semispinalis capitis and semispinalis cervicis were segmented by a blinded assessor and analyzed. RESULTS: Higher MFI was found in right trapezius (p = 0.007, Cohen's d = 0.9) among participants with severe chronic WAD compared to healthy controls. No other significant difference was found for MFI (p = 0.22-0.95) or MV (p = 0.20-0.76). CONCLUSIONS: There are quantifiable changes in muscle composition of right trapezius on the side of dominant pain and/or symptoms, among participants with severe chronic WAD. No other statistically significant differences were shown for MFI or MV. These findings add knowledge of the association between MFI, muscle size and self-reported neck disability in chronic WAD. TRIAL REGISTRATION: NA. This is a cross-sectional case-control embedded in a cohort study.

Morphology and composition of the ventral neck muscles in individuals with chronic whiplash related disorders compared to matched healthy controls: a cross-sectional case-control study.

BACKGROUND: OBJECTIVE: Studies of cross-sectional area (CSA) (morphology) and muscle fat infiltration (MFI) (composition) in ventral neck muscles is scarce in patients with chronic whiplash associated disorders (WAD), especially for men and those with severe WAD compared with matched healthy controls. The aim was to compare CSA and MFI of sternocleidomastoid (SCM), longus capitis (LCA) and longus colli (LCO) in patients with chronic right-sided dominant moderate (Neck Disability Index: NDI < 40) or severe WAD (NDI ≥ 40), compared to age- and sex-matched healthy controls. METHODS: Cross-sectional case-control study with blinded investigators. Thirty-one patients with chronic WAD (17 women and 14 men, mean age 40 years) (SD 12.6, range 20-62)) and 31 age- and sex-matched healthy controls underwent magnetic resonance imaging of ventral neck muscles segmental level C4. RESULTS: Unique to the severe group was a larger magnitude of MFI in right SCM (p = 0.02) compared with healthy controls. There was no significant difference between the groups with regards to the other muscles and measures. CONCLUSIONS: Individuals with severe right-sided dominant WAD have a higher MFI in the right SCM compared to healthy controls. No other differences were found between the groups. The present study indicates that there are changes in the composition of muscles on the side of greatest pain.

Cervical musculoskeletal, physical and psychological factors associated with ongoing dizziness in patients with whiplash associated disorder, 12 months after undertaking a neck specific or general exercise intervention.

BACKGROUND: Exercise in the management of persistent whiplash often doesn't specifically address dizziness. This study aimed to determine cervical musculoskeletal and sensorimotor measures, quality of life and psychological factors associated with the presence of dizziness in individuals with persistent whiplash 12 months post exercise intervention commencement. METHODS: A retrospective cross sectional review of questionnaires on dizziness, physical and psychological disability, quality of life and physical measures prospectively collected from 172 individuals during a randomised controlled trial. Associations between dizziness at 12 months post intervention and possible predictors was analysed with simple and multiple logistic regression models. RESULTS: Sixty-three % reported dizziness with a mean University of California Los Angeles dizziness score of 9 (SD 5) and dizziness intensity during activity of 26 mm (SD 24). They had poorer performance on sharpened Rhomberg, Neck muscle endurance (NME), and range of motion, elevated scores on pain, Neck disability index (NDI) and psychological and quality of life measures compared to those without dizziness. Less improvement in NDI and NME flexion from baseline to 12 months post exercise commencement, along with some baseline covariates were related to persistent dizziness and explained 50% of the variance. CONCLUSION: Dizziness following exercise at 12 months post follow-up was associated with lack of improvement in NDI and NME flexion suggesting a cervicogenic role. Alternatively, the presence of dizziness may inhibit exercise response. Additional causes or contributing factors of dizziness should be investigated in those with persistent whiplash to improve quality of life.

Evaluation of implementation and effectiveness of neck-specific exercise for persistent disability and pain after whiplash injury: study protocol for a randomized controlled study using a hybrid 2 design.

BACKGROUND: Persistent pain and disability in whiplash-associated disorders (WAD) grades II and III are common. In two randomized controlled trials (RCTs) of neck-specific exercises (NSE), we have seen promising results in chronic WAD, with a sustained clinically important reduction in pain and disability. NSE can also be delivered through internet support (NSEIT) and a few visits to a physiotherapist, saving time and cost for both patients and providers. NSE have been shown to have positive effects in other neck pain disorders and we will evaluate the diffusion of the exercises to other patients. The aims of the proposed study are to evaluate an implementation strategy for NSEIT and NSE in primary health care and to evaluate the effectiveness of NSEIT and NSE in clinical practice. METHODS: The proposed study is a prospective cluster-randomized mixed-design study with hybrid 2 trial design. Reg. physiotherapists working in twenty physiotherapy clinics will be included. The primary implementation outcome is proportion of patients with neck pain receiving neck-specific exercise. Secondary outcomes are; physiotherapists attitudes to implementation of evidence-based practice, their self-efficacy and confidence in performing NSEIT/NSE, number of patients visits, and use of additional or other exercises or treatment. To further evaluate the implementation strategy, two qualitative studies will be performed with a sample of the physiotherapists. The primary outcome in the patient effectiveness evaluation is self-reported neck disability according to the Neck Disability Index (NDI). Secondary outcomes are pain intensity in the neck, arm, and head; dizziness; work- and health-related issues; and patient's improvement or deterioration over time. All measurements will be conducted at baseline and at 3 and 12 months. Physiotherapists´ self-efficacy and confidence in diagnosing and treating patients with neck pain will also be evaluated directly after their instruction in NSEIT/NSE. DISCUSSION: This trial will evaluate the implementation strategy in terms of adoption of and adherence to NSEIT and NSE in clinical primary health care, and measure diffusion of the method to other patients. In parallel, the effectiveness of the method will be evaluated. The results may guide physiotherapists and health care providers to sustainable and effective implementation of effective exercise programs. TRIAL REGISTRATION: The randomized trial is registered on ClinicalTrials.gov , NCT05198258 , initial release date January 20, 2022.

Does Pain Extent Predict Ongoing Pain and Disability in Patients with Chronic Whiplash-Associated Disorders?

This study investigates whether baseline pain extent, extracted from an electronic pain drawing, is an independent predictive factor of pain and disability measured 1 year and 2 years later in people with chronic WAD. Participants completed questionnaires assessing neck pain intensity, disability via the Neck Disability Index (NDI), psychological features, and work ability. Participants also completed electronic pain drawings from which their pain extent was extracted. A two-step modelling approach was undertaken to identify the crude and adjusted association between pain extent and NDI measured at 1-year and 2-year follow-ups. A total of 205 participants were included in the analysis. The univariate analysis showed that pain extent was significantly associated with the NDI score at the 1-year (p = 0.006, 95% CI: 0.159-0.909) and 2-year (p = 0.029, 0.057-0.914) follow-ups. These associations were not maintained when we introduced perceived disability, psychological health, and work ability into the model after 1 year (p = 0.56, 95%CI: -0.28-0.499) and 2 years (p = 0.401, -0.226-0.544). Pain extent, as an independent factor, was significantly associated with perceived pain and disability in patients with chronic WAD for up to 2 years. This association was masked by neck disability, psychological health, and work ability.

Factors associated with neck and shoulder pain: a cross-sectional study among 16,000 adults in five county councils in Sweden.

BACKGROUND: Neck and shoulder pain is common in the general population, but studies on factors related to the risk of neck and shoulder pain have produced inconclusive results. Known factors related to pain include general physical activity, exercise, sleep disorders, and lifestyle, but further research is needed to improve our ability to prevent neck and shoulder pain. The aim was to investigate whether neck and shoulder pain are associated with physical domains (i.e., aerobic physical activities, general physical activities, and sitting time), sleep disturbances, general health, job satisfaction, and/or working time. METHODS: This population-based, cross-sectional study was conducted in Sweden in 2017 and included 16,167 individuals, aged 18 to 63 years. We administered a questionnaire to determine neck and shoulder pain, the time spent in general physical activity or aerobic physical activity, the time spent sitting, sleep disturbances, general health, job satisfaction, and the time spent working. Factors associated with neck and shoulder pain were explored using logistic regression. RESULTS: Significant factors associated with neck and shoulder pain were: overall health, sleep quality, and aerobic exercise. The odds of sustaining neck and shoulder pain increased with moderate or poor health (odds ratios [ORs]: 2.3 and 2.8, respectively) and sleep disorders (OR: 1.7). Conversely, aerobic physical activity performed more than 60 min/week at a level that enhanced respiratory and heart rate was associated with a reduced risk of experiencing neck and shoulder pain (OR: 0.8). CONCLUSIONS: Although no causal relationships could be determined in the present study, the results highlight important associations between aerobic exercise, undisturbed sleep, good health, and the absence of upper body pain. Exercises that enhance breathing and heart rate were associated with a reduced risk of experiencing neck or shoulder pain, but there was no association between general physical activity and upper body pain. Therefore, clinicians may not recommend low-intensity activities, such as walking, for preventing or improving neck and shoulder pain.

Neck-related function and its connection with disability in chronic whiplash-associated disorders: secondary analysis of a randomized controlled study.

BACKGROUND: More than 40% of individuals with whiplash injury experience persistent neck pain and disability years later, called whiplash-associated disorders (WAD). A randomized controlled trial evaluated three exercise interventions in WAD and found that neck-specific exercise (NSE) and NSE with a behavioral approach (NSEB) significantly improve disability compared to prescribed physical activity (PPA). However, the relationship between neck-related function and disability is inconclusive and needs to be further investigated. AIM: The present study compares the effect of NSE, NSEB, and PPA on neck muscle endurance (NME), active cervical range of motion (AROM), grip strength, and pain intensity immediately before and after the physical tests, and neck disability in individuals who are below or above the cut-off for normative reference values regarding NME, AROM, and grip strength. DESIGN: Follow-up to a multicenter randomized clinical trial. SETTING: Primary healthcare centers and hospital outpatient services. POPULATION: The selected population of this study included 216 patients with persistent WAD grades II and III. METHODS: This is a secondary analysis including 12 months' follow-up. NME, AROM, grip strength, pain, and self-reported disability were recorded at baseline, 3, 6, and 12 months. Linear mixed models were used, and sub-group analyses evaluated by non-parametric tests. RESULTS: NSE and NSEB resulted in greater improvements compared to PPA (P<0.01) in ventral (only males) and dorsal NME, AROM, and pain intensity during testing. We found no significant between-group differences in grip strength and no significant differences between the NSE and NSEB groups. Improvement in disability was seen at the 12-month follow-up of NSE and/or NSEB for individuals both below and above the cut-off reference values for NME and AROM. Individuals in the PPA group below the reference values for NME and AROM reported increasing disability at 12 months compared to baseline. CONCLUSIONS: The results suggest that neck-specific exercises (i.e., NSE, NSEB) improve clinical function and decrease disability in chronic WAD compared to PPA, but PPA can increase disability for patients with low neck-related function. CLINICAL REHABILITATION IMPACT: Higher neck-related function seems to be important for reduced disability in persistent WAD grades II and III. Neck-specific exercises could lead to higher neck-related function.

Extended roles in primary care when physiotherapist-initiated referral to X-ray can save time and reduce costs.

OBJECTIVE: The objective of this study was to evaluate an extended role for the physiotherapist in primary care in referring patients to plain X-ray. METHODS: This prospective cohort study was set in a single region in Sweden. It included 20 physiotherapists who were educated in a 1-day training in performing referral to X-ray, along with 107 patients with musculoskeletal disorders who were referred to X-ray. We evaluated referral quality and patient and physiotherapist satisfaction and calculated healthcare and patient costs. RESULTS: All referrals fulfilled the basic requirements of quality, and 78% were classified as good, fulfilling all criteria. Both patients and physiotherapists were satisfied with the extended role for the physiotherapist that decreased the waiting time to diagnosis and to adequate treatment. Costs were reduced for patients (by €53/patient) and healthcare (by €6286.2/107 patients). The cost to visit a physician was twice that of a physiotherapist visit. CONCLUSIONS: An extended role for physiotherapists in primary care in referring patients to X-ray was effective and safe for patients and reduced costs for patients and for healthcare. Physiotherapists in primary care were able to refer patients to X-ray after a 1 day of training, and the extended role freed up 45 min of physician time for each patient with a musculoskeletal disorder in need of an X-ray.

Adoption of a research-based program for neck disorders implemented in primary care physiotherapy: a short- and long-term follow-up survey study.

Neck disorders are common in primary health care (PHC) physiotherapy. A neck-specific exercise program based on research findings was implemented among physiotherapists in Swedish PHC. The aim of the study was to evaluate the adoption of the program. We invited PHC physiotherapists to an educational session including theoretical information and practical training. Before the educational session the participants (n = 261) completed a baseline questionnaire. After 3 and 12 months, we distributed surveys to identify changes in practice and in confidence regarding diagnosis and treatment. We compared data from 3-months and 12-months follow-up, respectively, with baseline data. Self-reported frequency of most of the included assessment methods was unchanged after 12 months. Frequency of assessment of neck proprioception had increased significantly. Specific neck muscle exercise for treatment of whiplash associated disorders was applied more frequently after 3 and after 12 months than at baseline. Frequency of other treatment methods remained unchanged. Confidence in diagnosis and treatment increased significantly, particularly among women. The program was not adopted as expected, but resulted in increased confidence regarding diagnosis and treatment. The provision of a short educational session seemed not to be sufficient to obtain a sustained change in practice.

Ultrasound Investigation of Dorsal Neck Muscle Deformation During a Neck Rotation Exercise.

OBJECTIVES: Neck-specific exercise can reduce neck pain and increase function, but information on how different neck muscle layers are activated during neck exercises is scarce. The aim of this study was to investigate deformation and deformation rate in 5 dorsal neck muscles and the correlation among these muscles during a loaded dynamic exercise used in clinical practice. METHODS: Deformation and deformation rate were investigated in 5 dorsal right-sided neck muscles in 20 individuals without neck pain using ultrasonography and speckle-tracking analyses. Repeated-measures analysis of variance was used to measure differences between the muscles, and correlations between neck muscles were analyzed with Kendall's tau. RESULTS: Deformation in left (contralateral) rotation showed significant differences among the muscles (P = .01), with higher deformation of the semispinalis capitis muscle compared with the trapezius muscle (P = .02). There were no significant differences among the 5 neck muscles in right (unilateral) rotation (P = .46). There were significant differences in deformation rate among muscles in both right and left rotation (P < .01). The trapezius muscles have the lowest deformation rate in right rotation (P < .01). In left rotation, the trapezius and multifidus muscles showed lower deformation rates compared with most of the other muscles (P < .03). Almost all muscles were correlated in both deformation and deformation rate. CONCLUSION: The quadruped standing loaded dynamic neck exercise seemed to activate all the investigated neck muscles, with a tendency for more activation of the semispinalis capitis.

Neck-specific exercise for radiating pain and neurological deficits in chronic whiplash, a 1-year follow-up of a randomised clinical trial.

Up to 90% of people with neurological deficits following whiplash injury report chronic symptoms. A recent unique study of neck-specific exercise showed positive results (post-intervention at 12 weeks), regarding arm pain and neurological deficits in people with chronic whiplash associated disorders (WAD). This 1-year follow-up of that randomised controlled study with assessor blinding aimed to examine whether neck-specific exercise with (NSEB) or without (NSE) a behavioural approach has long-term benefits over physical activity prescription (PPA) regarding arm pain and neurological deficits (n = 171). Interventions were: NSE, NSEB, or PPA. Follow-up of arm pain, paraesthesia bothersomeness (questionnaires) and clinical neurological tests were performed after 3, 6 and 12 months and analysed with Linear Mixed Models and General Estimating Equations. The NSE and/or NSEB groups reported significantly less pain and paraesthesia bothersomeness as well as higher odds of normal key muscle arm strength and of normal upper limb neural tension over the year (all p < 0.03), compared with PPA. In conclusion, results suggest that neck-specific exercise with or without a behavioural approach may have persisting long term benefits over PPA regarding arm pain and clinical signs associated with neurological deficits in chronic WAD.

Exercise, headache, and factors associated with headache in chronic whiplash: Analysis of a randomized clinical trial.

BACKGROUND: Almost 40% of individuals with chronic whiplash-associated disorders (WAD) report headache after 5 years, making it one of the most common persistent symptoms besides neck pain, but randomized treatment studies are lacking. This study aimed to evaluate the effect of 3 different exercise approaches on headache in chronic WAD grades 2 and 3, and to identify potential factors associated with such headache, and whether they differ depending on 3 different aspects of such headache (current headache, maximum headache, or headache bothersomeness). METHODS: This was an analysis of a randomized clinical trial of people with chronic WAD and headache (n = 188), who were randomized to either 12 weeks of neck-specific exercise without (NSE) or with a behavioral approach (NSEB) or physical activity prescription (PPA). Data were collected at baseline and at 3, 6, and 12 months. Physical and psychosocial factors were tested for association with headache. Multivariate regression models and linear mixed models were used. RESULTS: The NSE/NSEB groups reported reduced headache both over time and compared to PPA. Up to 51% (NSE) and 61% (NSEB) reported at least 50% reduction in their headache at 12 months. The PPA group was not improved over time. Neck pain and dizziness were associated with headache regardless of aspect of headache. The only associated psychosocial factor was anxiety, which was associated with headache bothersomeness. Other factors were mainly physical, and up to 51% of the variance was explained. CONCLUSION: Headache in chronic WAD, may be reduced with neck-specific exercise with or without a behavioral approach. Chronic headache was associated with neck pain and dizziness regardless of aspect tested. Other factors associated with headache in chronic WAD were mainly physical rather than psychosocial. TRIAL REGISTRATION NUMBER: Clinical Trials.gov, no: NCT015285.

Ultrasound imaging of dorsal neck muscles with speckle tracking analyses - the relationship between muscle deformation and force.

The development of methods of non-invasive measurement of neck muscle function remains a priority in the clinical sciences. In this study, dorsal neck muscle deformation vs time curves (deformation area) were evaluated against incremental force, recorded from non-invasive real-time ultrasound measurement. The results revealed subject-specific moderate to strong linear or non-linear relationships between deformation and force. Test-retest variability showed strong reliability for all five neck muscles summed together and fair to good reliability for the five muscles evaluated separately. Multivariate statistics were used to analyse the interactions between the dorsal neck muscles during different percentages of maximal voluntary contraction (MVC). Low force (10-20% MVC) was related to muscle shortening; higher force (40-80% MVC) showed combination of shortening and elongation deformation in the muscle interactions. The muscle interactions during isometric MVC test were subject-specific, with different combinations and deformations of the five neck muscles. Force ≥40% MVC were associated with a forward movement of the cervical spine that affected the ultrasound measurement of the dorsal neck muscles. Ultrasound with speckle-tracking analyses may be best used to detect low levels (<40% MVC) of neck muscle activity.

Investigating the Causal Mechanisms of Symptom Recovery in Chronic Whiplash-associated Disorders Using Bayesian Networks.

OBJECTIVES: The present study's objective was to understand the causal mechanisms underpinning the recovery of individuals with whiplash-associated disorders (WAD). We applied Bayesian Networks (BN) to answer 2 study aims: (1) to identify the causal mechanism(s) of recovery underpinning neck-specific exercise (NSE), and (2) quantify if the cyclical pathway of the fear-avoidance model (FAM) is supported by the present data. MATERIALS AND METHODS: We analyzed a prospective cohort data set of 216 individuals with chronic WAD. Fifteen variables were used to build a BN model: treatment group (NSE with or without a behavioral approach, or general physical activity), muscle endurance, range of motion, hand strength, neck proprioception, pain catastrophizing, fear, anxiety, depression, self-efficacy, perceived work ability, disability, pain intensity, sex, and follow-up time. RESULTS: The BN model showed that neck pain reduction rate was greater after NSE compared with physical activity prescription (ß=0.59 points per month [P<0.001]) only in the presence of 2 mediators: global neck muscle endurance and perceived work ability. We also found the following pathway of variables that constituted the FAM: anxiety, followed by depressive symptoms, fear, catastrophizing, self-efficacy, and consequently pain. CONCLUSIONS: We uncovered 2 mediators that explained the mechanisms of effect behind NSE, and proposed an alternative FAM pathway. The present study is the first to apply BN modelling to understand the causal mechanisms of recovery in WAD. In doing so, it is anticipated that such analytical methods could increase the precision of treatment of individuals with chronic WAD.

Validity, internal consistency and self-rated change of the patient enablement instrument in patients with chronic musculoskeletal pain.

OBJECTIVE: Patient enablement reflects patient's understanding of and coping with illness. The aim of this study was to investigate the content validity, construct validity, internal consistency and self-rated change (SRC) of the Patient Enablement Instrument (PEI) in patients with whiplash-associated disorders, cervical radiculopathy and mixed chronic pain treated in different settings. DESIGN: Psychometric analyses. PARTICIPANTS: Patients with disabling non-malignant chronic musculoskeletal pain. METHODS: Participants answered questionnaires on disability (Neck Disability Index (NDI) or Functional Rating Index (FRI)), anxiety/depression (Hospital Anxiety and Depression Scale; HADS) and general health (EuroQol; EQ-5D). Content validity, construct validity (confirmatory factor analysis), internal consistency and cut-off for SRC were investigated for the PEI after treatment. The SRC value was the receiver operating characteristic (ROC) curve optimal cut-off point. RESULTS: After treatment all items were completed by 516 patients (mean standard deviation (SD) age 45.1 years (SD 10.1), women 75% (n = 385)). The 1-factor PEI model had approximate fit to the data. The internal consistency Cronbach's alpha was between 0.878 and 0.929 for the 3 groups. Correlations between the PEI and the NDI/FRI, HADS and EQ-5D were fair to good. The SRCROC for whiplash-associated disorders, cervical radiculopathy and mixed chronic pain groups was 5, 6 and 4 points in the PEI, respectively. CONCLUSION: The PEI showed fair content validity, construct validity and internal consistency. However, the scale needs further development to improve measurement of change.

Pathophysiology behind prolonged whiplash associated disorders: study protocol for an experimental study.

BACKGROUND: There is insufficient knowledge of pathophysiological parameters to understand the mechanism behind prolonged whiplash associated disorders (WAD), and it is not known whether or not changes can be restored by rehabilitation. The aims of the projects are to investigate imaging and molecular biomarkers, cervical kinaesthesia, postural sway and the association with pain, disability and other outcomes in individuals with longstanding WAD, before and after a neck-specific exercise intervention. Another aim is to compare individuals with WAD with healthy controls. METHODS: Participants are a sub-group (n = 30) of individuals recruited from an ongoing randomized controlled study (RCT). Measurements in this experimental prospective study will be carried out at baseline (before intervention) and at a three month follow-up (end of physiotherapy intervention), and will include muscle structure and inflammation using magnetic resonance imaging (MRI), brain structure and function related to pain using functional MRI (fMRI), muscle function using ultrasonography, biomarkers using samples of blood and saliva, cervical kinaesthesia using the "butterfly test" and static balance test using an iPhone app. Association with other measures (self-reported and clinical measures) obtained in the RCT (e.g. background data, pain, disability, satisfaction with care, work ability, quality of life) may be investigated. Healthy volunteers matched for age and gender will be recruited as controls (n = 30). DISCUSSION: The study results may contribute to the development of improved diagnostics and improved rehabilitation methods for WAD. TRIAL REGISTRATION: Clinicaltrial.gov Protocol ID: NCT03664934, initial release 09/11/2018.