Neural and muscular factors associated with motor impairment in neck pain

Posterior neck weighting an innovative and novel head orthosis for forward head posture correction: Randomized controlled trial

Background

Muscle activity of the anterior and posterior elements of the cervical spine, both together actively contribute to the balance of the head position over the neck. Increasing muscular tension of the one cervical muscle group could induce poor motor control of cervical spine joints, this might contribute to the anterior position of the head with neck, known as forward head posture (FHP). We propose posterior neck weighting as an innovative orthosis to correct head posture within FHP participants and improve co-related mechanical neck pain.

Methods

Sixty-one participants with FHP; were randomly assigned to one of two groups posterior cervical weighing orthosis (PCWO) or deep cervical flexion (DCF) exercise. Each participant has been assessed for change in Craniovertebral Angle (CVA) as an indicator for FHP severity, and neck disability index (NDI).

Results

Wilcoxon Signed Rank Test showed a statistically significant change difference regarding the degree of CVA improvements, and the score of NDI of pre-and post-intervention of the PCWO group (p < 0.0001), (p < 0.0001), and of the DCF group (p < 0.0001), (p = 0.0039), respectively. Mann-Whitney Test, showed a statistically significant difference between groups for CVA improvement (p < 0.0001), and NDI (p = 0.045). No correlation between CVA and NDI scores within the PCWO group (r = 0.129, p = 0.473), and within the DCF exercise group (r = 0.073, p = 0.71).

Conclusion

PCWO is a novel and innovative neck orthosis that is considered a promising intervention to correct FHP and improve correlated neck disability.

Development of the Sensory-Motor Dysfunction Questionnaire and Pilot Reliability Testing

Both chronic and recurrent spinal pain alter sensorimotor integration (SMI), which is demonstrated using complex neurophysiological techniques. Currently, there is no patient-reported outcome measure that documents and/or assesses SMI in populations with spinal problems. The purpose of this study was to develop the Sensory-Motor Dysfunction Questionnaire (SMD-Q) and assess its test-retest reliability and internal consistency in individuals with recurrent spinal pain. The SMD-Q was developed based on the existing literature on motor control disturbances associated with disordered SMI. The initial SMD-Q drafts underwent review by two separate panels of subject matter experts and a focus group with subclinical spine pain. Their suggestions were incorporated into the questionnaire prior to reliability testing. The questionnaire was administered twice at a seven-day interval using QualtricsTM. A total of 20 participants (14 females and 6 males; 20.95 ± 2.46 years of age) completed the study. Quadratic weighted kappa (Kw) was used to assess test-retest reliability and Cronbach's alpha (α) was used to assess internal consistency. Four items had a Kw < 0.40, seven had a 0.40 < Kw < 0.75, and one had a Kw > 0.75 (excellent agreement), with excellent internal consistency (α > 0.90). The pilot SMD-Q appears to reliably measure altered SMI, suggesting that revisions and testing with a larger sample are worth pursuing.

Comparison of Flexion Relaxation Phenomenon After Single-Level and Multi-Level Anterior Cervical Discectomy and Fusion

BACKGROUND

This prospective cohort study aimed to assess the influence of the number of fused segments in cervical paravertebral muscles by comparing the changes of the cervical flexion relaxation phenomenon (FRP) after single-level versus multilevel anterior cervical discectomy and fusion (ACDF).

METHODS

A total of 115 patients who had undergone ACDF were retrospectively recruited and divided into a 1-level group (n = 44), a 2-level group (n = 40) and a 3- to 4-level group (n = 31). The flexion relaxation experiment was carried out 3 days preoperatively and 12 months postoperatively by surface electromyography (SEMG). Patients were examined using the neck visual analog scale, cervical Japanese Orthopedic Association score, Neck Disability Index, and C2-C7 range of motion (ROM).

RESULTS

There was a significant difference in the time-related changes in flexion relaxation ratio (FRR) among the 3 study groups before and after surgery (F = 85.701; P < .001). Thirty-five patients (79.55%) with 1-level ACDF and 11 patients (27.5%) with 2-level ACDF had FRP were restored to normal at 12 months postoperatively; however, only 1 patient (3.33%) had normalized FRP after 3- to 4-level ACDF. There were significant differences in the time-related changes of the normalized SEMG root mean square values in each phase before and after surgery (P = .018, <.001, <.001, and <.001). A significant correlation was found between the changes in C2-C7 ROM and FRR in the 3 study groups (P = .007 for 1 level, P = .003 for 2 levels, and P = .036 for 3-4 levels).

CONCLUSIONS

Single-level ACDF contributes to normalizing the FRP of cervical paravertebral muscles, which is not ideally recovered by 2-level ACDF. In contrast, 3- or 4-level ACDF could not normalize the cervical FRP. Our research supports the passive structure hypothesis.

Prevalence of sleep disturbance in patients with cervical radiculopathy and an analysis of risk factors: a cross-sectional study

OBJECTIVE

Previous research has shown that many patients with musculoskeletal diseases suffer from sleep disturbances. However, the sleep quality of patients with cervical radiculopathy (CR) has yet to be fully investigated. This study aims to investigate the prevalence and status of sleep disturbances in patients with CR and identify the mechanisms and risk factors associated with this condition.

METHODS

We conducted a cross-sectional study of patients diagnosed with CR. The Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI) were used to evaluate the sleep quality of patients and determine whether patients experience sleep disturbances. In addition, we analyzed the clinical and radiological risk factors of sleep disturbance and determined the key risk factors related to sleep disturbance by multivariable analysis.

RESULTS

According to specific inclusion and exclusion criteria, 186 patients with CR were finally included, with a mean age of 59.1 ± 14.3 years, of which 113 (60.8%) were female. Sleep disturbance was defined as a PSQI score ≥ 6 and was identified in 56.5% of patients (105/186). By performing multivariate analysis, we determined that sleep disturbance was closely related to the female gender, a higher Beck Depression Inventory (BDI) score, a reduction in cervical mobility, an increase in C2-C7 sagittal vertical axis (C2-C7 SVA), and severe asymmetry of the paravertebral muscle at C5 and C6 levels.

CONCLUSION

In this study, we identified the high prevalence and potential high-risk factors of sleep disturbance in patients with CR. Clinicians should closely evaluate and monitor such patients and consider appropriate treatment strategies.

LEVEL OF EVIDENCE

IV.

Cervical and axioscapular muscle stiffness measured with shear wave elastography: A comparison between different levels of work-related neck disability

Assessing muscle mechanical properties in terms of stiffness may provide important insights into mechanisms underlying work-related neck pain. This study compared stiffness of cervical and axioscapular muscles between 92 participants (sonographers) with no (n = 31), mild (n = 43) or moderate/severe (n = 18) neck disability. It was hypothesized that participants with more severe neck pain and disability would present with altered distribution of stiffness in cervical and axioscapular muscles than those with no disability. Using shear wave elastography, the shear modulus (kPa) of five cervical and six axioscapular muscles or muscle segments were measured in a relaxed seated upright or side-lying position. Muscle activity was measured simultaneously using surface electromyography during the elastography measurements and scapular depression was measured using a measurement tape and inclinometer before the elastography measurements to evaluate their potential confounding influences on shear modulus. Increased shear modulus was found in deeper than superficial cervical muscles and more cranial than caudal axioscapular muscles. However, no differences in shear modulus of the cervical or axioscapular muscles were found between sonographers with varying levels of disability. This study suggests no alterations in stiffness of cervical and axioscapular muscles were associated with work-related neck pain and disability.

Specific versus non-specific exercises for the neck extensor muscles in women with chronic idiopathic neck pain: A randomized controlled trial

BACKGROUND

Structural and functional impairments of the cervical extensor muscles have been demonstrated in people with neck pain. A global exercise approach targeting all neck extensor muscles has shown positive effects in this population. However, to date, the efficacy of exercises specifically targeting the deep neck extensors has neither been tested nor compared to global exercises for the neck extensors.

OBJECTIVES

To compare the effects on pain and disability of a specific lower deep neck extensors (SLDNE) versus a general neck extensor (GNE) exercise program in women with chronic idiopathic neck pain.

METHODS

Fourty-three women with chronic idiopathic neck pain were randomly allocated to either a six-week SLDNE or a GNE exercise program. As primary outcome, neck disability was measured with the Neck Disability Index (NDI). Secondarily, pain intensity (VAS), cervical ROM, pressure pain thresholds (PPTs), cervical and thoracic posture and self-perceived benefit of treatment (GROC) were also measured. Every outcome was measured at baseline and immediately after treatment, except NDI, which was also measured at 6-months follow-up. The GROC was only assessed post-intervention.

RESULTS

Both exercise programs lead to reduced neck disability immediately post-intervention (within-group mean difference [MD] = -6.09; 95% Confidence Interval [CI]: 7.75, -4.42 and -4.73; 95%CI: 6.57, -2.91 respectively) and at the 6-months follow-up (-4.47; 95%CI: 6.41, -2.53 and -4.74; 95%CI: 6.50, -2.97), but with no between group differences. Similar results were found for pain intensity post-intervention, with no between group interaction (within-group MD = -20.87 mm; 95% CI: 28.55, -13.19 and -18.00 mm; 95%CI: (-26.24, -9.76) for SLDNE and GNE groups, respectively). GROC improved after both interventions without any between-group difference.

CONCLUSIONS

A six-week exercise program specifically targeting the lower deep neck extensors lead to comparable outcomes as a general neck extensor exercise program in women with chronic idiopathic neck pain.

Effects of clinical pilates exercises in patients with chronic nonspecific neck pain: a randomized clinical trial

BACKGROUND

Neck pain is a common musculoskeletal problem in adults. Clinical pilates exercises can be beneficial managing the pain and improving the risk factors.

AIMS

The aim of this study was to investigate the effects of clinical pilates exercises on pain and disability, deep neck flexor endurance (DNFE), posture, cervical range of motion (CROM), and proprioception in patients with chronic nonspecific neck pain.

METHODS

Fifty patients with chronic nonspecific neck pain were randomized into two groups. The clinical pilates exercise group (CPEG) received clinical pilates exercises for 6 weeks. The control group (CG) received posture education. Pain and disability, DNFE, forward head angle (FHA) and forward shoulder angle (FSA) degrees, CROM, and joint position error (JPE) were measured before and after 6 weeks.

RESULTS

Clinical pilates exercises improved pain, Neck Disability Index (NDI), DNFE, posture, CROM (except extension), and JPE (p < 0.05). We found significant differences between CPEG and CG in the comparisons for the change of pain, NDI, DNFE, FSA, CROM (except extension), and JPE (except left rotation) (p < 0.05). NDI, FSA, and rotational JPE also improved in CG (p < 0.05). However, these improvements were significantly better in CPEG than CG (p < 0.05) except JPE in left rotation (p = 0.118).

CONCLUSION

In patients with chronic nonspecific neck pain, clinical pilates exercise is a safe and effective method to improve pain and disability, DNFE, posture, ROM, and proprioception.

CLINICAL TRIAL REGISTRATION

NCT03782584 retrospectively registered December 20 2018.

Electromyographic Activity of Sternocleidomastoid Muscle in Individuals With Neck Pain and Healthy Volunteers: A Reliability and Between-Group Differences Examination

OBJECTIVES

The purpose of this study was to evaluate the electromyographic activity of the sternocleidomastoid muscle during the performance of the craniocervical flexion test (CCFT) in individuals with neck pain and healthy volunteers, assess the reliability of this method, and examine possible between-population differences.

METHODS

Electromyographic activity of the sternocleidomastoid muscles of 22 individuals with neck pain and 22 healthy participants was recorded during the 55 stages of the CCFT. Pain (visual analog scale) and disability (Neck Disability Index) levels and pain duration were recorded for the participants with neck pain. Reliability of electromyography was evaluated with the intraclass correlation coefficient, standard error of measurement, and minimum detectable change.

RESULTS

Within-day reliability indices of electromyographic activity were very good to excellent (intraclass correlation coefficients, 0.86-0.98; standard error of measurement, 1.8%-7.6%; minimum detectable change, 5.0%-21.1%). For the head-lift normalization method, 2-way analysis of variance revealed significant between-group differences (P < .02); however, these were not clinically significant when reliability test-retest error was considered. Differences between contraction levels were significant (P < .001); however, the group by contraction level interaction factor was nonsignificant. Therefore, the between-groups electromyographic increases noted with increasing contraction levels were similar. No correlation was identified between participants' electromyography data and pain or disability.

CONCLUSION

In participants with moderate pain, disability, and pain duration, no clear alterations in electromyographic activity of the sternocleidomastoid could be detected with the CCFT. Reliability of the test used was very good.

Head Pitch Angular Velocity Discriminates (Sub-)Acute Neck Pain Patients and Controls Assessed with the DidRen Laser Test

Understanding neck pain is an important societal issue. Kinematic data from sensors may help to gain insight into the pathophysiological mechanisms associated with neck pain through a quantitative sensorimotor assessment of one patient. The objective of this study was to evaluate the potential usefulness of artificial intelligence with several machine learning (ML) algorithms in assessing neck sensorimotor performance. Angular velocity and acceleration measured by an inertial sensor placed on the forehead during the DidRen laser test in thirty-eight acute and subacute non-specific neck pain (ANSP) patients were compared to forty-two healthy control participants (HCP). Seven supervised ML algorithms were chosen for the predictions. The most informative kinematic features were computed using Sequential Feature Selection methods. The best performing algorithm is the Linear Support Vector Machine with an accuracy of 82% and Area Under Curve of 84%. The best discriminative kinematic feature between ANSP patients and HCP is the first quartile of head pitch angular velocity. This study has shown that supervised ML algorithms could be used to classify ANSP patients and identify discriminatory kinematic features potentially useful for clinicians in the assessment and monitoring of the neck sensorimotor performance in ANSP patients.

Cervical flexion relaxation phenomenon in patients with and without non-specific chronic neck pain

BACKGROUND

The cervical flexion relaxation phenomenon (FRP) is a myoelectric silence of neck extensor muscles which occurs after a certain degree of flexion. Impaired flexion relaxation can impose the vertebral structures to excessive loading resulting from the persistence of muscular contraction.

OBJECTIVE

This study aimed to investigate the incidence or absence of FRP in cervical erector spinae (CES) and upper trapezius muscles in patients with chronic neck pain (CNP).

METHODS

Twenty-five patients with CNP and 25 healthy volunteers were recruited. They accomplished cervical flexion and extension from a neutral position in four phases in the sitting position. The surface electromyography activity of both CES and upper trapezius muscles was recorded in each phase. Cervical flexion and extension movements were simultaneously measured using an electrogoniometer.

RESULTS

FRP in CES was observed in 84% and 36% of healthy subjects and CNP patients, respectively. Flexion relaxation ratio (FRR) in CES was lower in CNP patients than in healthy subjects (mean diff = 1.33; 95% CI: 0.75-1.91) (P< 0.001). Only in CNP patients, FRR in right erector spinea was significantly higher than that in the left erector spinea (P= 0.04).

CONCLUSIONS

FRP incidence in CNP patients was less than in healthy subjects. Moreover, this phenomenon begins later in CNP patients than in healthy subjects indicating prolonged activity of CES muscles during flexion in the CNP group. The difference between FRR in the right and left sides of erector spinea muscles can result in CNP.

Long-Term Efficacy of Treatment Effects After a Kyphosis Exercise and Posture Training Intervention in Older Community-Dwelling Adults: A Cohort Study

BACKGROUND AND PURPOSE

Treatments that prevent worsening kyphosis are important due to the progressive nature of kyphosis with aging. We assessed long-term efficacy of treatment effects after a short-term kyphosis exercise and posture training intervention in a cohort study among older adults with hyperkyphosis, and investigated whether long-term treatment effects differ among males and females.

METHODS

In the original kyphosis intervention, 112 older adults enrolled in a waitlist design randomized controlled trial. One hundred three participants, mean age 70.0 (5.7) years and kyphosis 52.0° (7.4°), completed a twice weekly, 3-month, group exercise and posture training intervention, and were eligible to enroll in the follow-up study. We compared (1) change in outcomes pre-/postintervention to change postintervention over the follow-up period, (2) change in outcomes pre-/postintervention and postintervention to follow-up, stratified by sex, and (3) long-term change postintervention to follow-up in males and females. Primary outcome was change in kyphometer-measured thoracic kyphosis. Secondary outcomes were change in lumbar lordosis, objective measures of physical function, self-reported measures of physical activity, and health-related quality of life (HRQoL).

RESULTS AND DISCUSSION

Forty-three participants, 42% of the eligible cohort, returned for follow-up, a mean 3.0 (0.7) years after completing the original intervention. Participants (27 females and 16 males) were 73.8 (6.1) years old, with mean kyphosis 48.9° (11.9°) at follow-up. Kyphosis declined -1.5° (95% confidence interval [CI]: -3.9° to 1.0°) postintervention to follow-up and this was no different than change pre-/postintervention, P = .173. Lordosis improved 8.9° (95% CI: 6.2° to 11.6°), more than change pre-/postintervention, P < .001. Gait speed measure of physical function increased 0.08 (95% CI: 0.02 to 0.14) m/s, Physical Activity Scale for the Elderly (PASE) measure of physical activity increased 4 (95% CI: -16 to 24) points, and Patient-Reported Outcomes Measurement Information System (PROMIS) mental health T-score measure of HRQoL increased 1.1 (95% CI: -1.0 to 3.1) points, but these improvements were not significantly more than change pre-/postintervention, P > .050. Other measures of physical function (modified Physical Performance Test [PPT], Timed Up and Go, and 6-minute walk) and HRQoL (Scoliosis Research Society [SRS-30] self-image and PROMIS physical function and physical health) declined at follow-up, significantly more than change pre/postintervention, P ≤ .050. Comparing change in outcomes pre-/postintervention and postintervention to follow-up, stratified by sex, both males and females increased lordosis, and decreased modified PPT and 6-minute walk measures of physical function, P < .050. Males and females differed in long-term change postintervention to follow-up. Time loaded standing and PASE improved in females compared with males, P = .008 and P = .092, respectively, and PROMIS mental health, physical health, and physical function declined in females compared with males, P = .073, P = .025, and P = .005, respectively.

CONCLUSIONS

In our follow-up study, a mean of 3.0 (0.07) years after a 3-month kyphosis exercise and posture training intervention, kyphosis maintained and did not progress as expected with age. There was long-term improvement in lordosis. Compared with treatment effects from the short-term intervention, gait speed maintained equally well in males and females, while trunk endurance improved in females. Further investigation of long-term benefits of a short-term kyphosis exercise and posture training intervention is warranted.

Cervico-thoracic pain and associated impairments in air force personnel: a cross-sectional study

BACKGROUND

Pain and impaired function in the cervical region are common in Air Force personnel (AFP), but evidence is limited regarding the thoracic region. This cross-sectional cohort study examined associations between cervico-thoracic pain and physical performance among Swedish AFP and explored possible differences and similarities in test performance between fighter pilots (FP), helicopter pilots (HP) and rear crew (RC).

METHODS

AFP (n = 73) from one airbase performed eight tests of movement control of the spine, active cervical range of motion (ROM) in all six directions and isometric strength and endurance of the cervical flexors and extensors. The association between test performance and cervico-thoracic pain (based on the 'Musculoskeletal screening protocol' questionnaire) were analysed in a multiple binary logistic regression model.

RESULTS

For AFP with cervico-thoracic pain (30%), movement control was impaired in the 'neck flexion test' (OR [95%CI] =3.61 [1.06-12.34]) and the 'forward lean test' (OR [95%CI] =3.43[1.04-11.37]), together with reduced flexion ROM (OR [95%CI] =0.93 [0.87-0.99]). Test performance was in general similar between the three groups, but FP and HP could control the 'forward lean test' to a significantly higher degree than RC (p = 0.000). Further, FP showed significantly greater ROM in lateral flexion to the right compared to HP and RC (mean: 40.3°, 36.2° and 33.4°, respectively, p = 0.000), and they showed higher, although not significant, flexor strength than RC (p = 0.026).

CONCLUSIONS

The impaired function associated with cervico-thoracic pain highlights the need for a deeper understanding of such relationships when designing tools to systematically optimize the physical performance and prevent pain among AFP. Studies with a longitudinal design are warranted to examine any causative associations between pain and impairments.

Comparison between velocity-specific exercise and isometric exercise on neck muscle functions and performance: a randomised clinical trial

Background

Evidence has shown that velocity-specific exercise results in additional benefits for peripheral joint muscles by promoting their functions, however, its effects on spinal muscles are yet to be investigated. This study aimed to examine the feasibility and effects of velocity-specific exercise compared to isometric exercise on cervical muscle functions and performance in healthy individuals.

Methods

Thirty healthy adults were randomised to practise either the velocity-specific exercise (VSE, n = 15) or isometric exercise (IE, n = 15) for 6 weeks. Functions and performance of the cervical extensors and flexors were assessed pre- and post-program, by analyzing the peak torque and electromyography during the isokinetic testing, and cross-sectional area of the deep cervical muscles at rest. The self-reported level of difficulty and post-exercise soreness during the exercise were recorded to evaluate the feasibility and safety of the two exercise programs.

Results

Both VSE and IE exercises resulted in significant improvement of the muscle functions and performance while there were no between-group differences at reassessment of the (a) cross-sectional area of longus colli and semispinalis capitis; (b) EMG amplitude in sternocleidomastoid and cervical erector spinae, and (c) peak torque values. Further analysis revealed that degree of correlation between extension torque and EMG amplitude of cervical erector spinae increased in both groups. However, significant correlation was found only in VSE group post-program. There were no significant differences for the level of difficulty and post-exercise soreness found between two groups.

Conclusions

Both velocity-specific and isometric exercises significantly promoted cervical muscle functions and performance. The present study confirms that velocity-specific exercise can be practised safely and it also contributes to a greater enhancement in neuromuscular efficiency of the cervical extensors. These findings indicate that the velocity-specific exercise can be considered as a safe alternative for training of the cervical muscles. Further study is recommended to examine its benefit and application for promoting the muscle functions and recovery in symptomatic individuals.

Comparison of neck extensor muscle endurance and cervical proprioception between asymptomatic individuals and patients with chronic neck pain

INTRODUCTION

Neck extensor endurance (NEE) and cervical proprioception are vital for maintaining cervical spine function and defects in these processes have been associated with chronic neck pain (CNP). The objectives of the study are 1) To investigate the association between NEE and cervical joint position error (JPE) in subjects with CNP; 2) to compare the cervical extensor endurance and cervical JPE of CNP subjects with those of asymptomatic controls; and 3) to determine the relationship between Pain Catastrophizing Scale (PCS) scores, NEE, and cervical JPE in subjects with CNP.

METHOD

Sixty-four participants (32 asymptomatic, 32 with CNP) participated in this comparative cross-sectional study. Cervical proprioception was assessed by measuring the absolute JPE in the sagittal and transverse directions. NEE was assessed using a clinical extensor endurance test. NEE capacity and JPE were compared and correlated between asymptomatic and CNP subjects. Pain catastrophic behavior was assessed using the Pain Catastrophizing Scale (PCS) in CNP subjects.

RESULTS

CNP subjects showed lower NEE capacity (p < 0.001) and significantly larger JPEs (p < 0.001) than asymptomatic participants. NEE negatively correlated with JPEs in all directions (p < 0.001) in asymptomatic subjects and only neck extension errors showed a correlation in CNP subjects (r = -0.45, p = 0.009). PCS scores were negatively correlated with endurance capacity (r = -0.42, p = 0.017) and positively correlated with JPE (flexion: r = 0.57, p = 0.001).

CONCLUSION

CNP subjects showed impaired proprioception and lower endurance capacity compared to asymptomatic participants. Neck extension errors alone correlated with JPE in CNP subjects. PCS scores negatively correlated with NEE in subjects with CNP.

Women with mechanical neck pain exhibit increased activation of their superficial neck extensors when performing the cranio-cervical flexion test

Several studies have analysed the activity of superficial neck flexors, but the activity of neck extensors has been less investigated in patients with neck pain OBJECTIVES: 1, to investigate the differences in the activation of superficial neck flexor and extensor musculature during the cranio-cervical flexion test (CCFT) in women with mechanical chronic neck pain when compared to asymptomatic women; 2, to investigate the correlation between neck muscle activity and the clinical features of neck pain DESIGN: Cross-sectional METHODS: Surface electromyography was recorded bilaterally from the sternocleidomastoid, anterior scalene, splenius capitis, and upper trapezius muscles of 30 women with mechanical chronic neck pain and 30 asymptomatic women as they performed the CCFT. Comparisons of the normalized root mean square between both groups were conducted with 2x5 ANCOVA with task level as the within-subjects variable, group as the between-subjects variable, and pain related-disability as a co-variate RESULTS: Women with mechanical neck pain exhibited increased activity of superficial neck flexors (sternocleidomastoid: F = 14.448, P < 0.001; anterior scalene: F = 21.693, P < 0.001) and superficial neck extensors (splenius capitis: F = 4.692, P < 0.001; upper trapezius: F = 4.245, P < 0.001) as compared to asymptomatic women. Higher pain related-disability was associated with more electrical activity of the anterior scalene and upper trapezius muscles during the CCFT CONCLUSIONS: Women with mechanical chronic neck pain exhibit an increased activity of their superficial neck flexors and superficial neck extensors during a low-load task such as CCFT when compared to asymptomatic pain-free women. Our results should be considered when designing therapeutic exercise programs for this population.

Asymmetry of Cervical Multifidus and Longus Colli Muscles Size in Participants With and Without Cervical Radicular Pain

OBJECTIVES

The aim of this study was to determine the asymmetry of cervical multifidus (MF) and longus colli (LC) muscles in patients with unilateral chronic radicular neck pain (CRNP) and healthy subjects using ultrasonography.

MATERIALS AND METHODS

Ninety five individuals (50 patients with unilateral CRNP and 45 healthy subjects) participated in this study. The size of the cervical MF and LC muscles; anterior posterior dimension (APD) and lateral dimension (LD); were bilaterally measured in a relaxed state using ultrasonography.

RESULTS

Patients with CRNP showed greater asymmetry in the cervical MF and LC muscles size than the healthy subjects. The mean percentages differences between sides for MF and LC muscles size was higher in patients than that of healthy subjects (for both APD and LD; P<0.05). The ratio of smaller to larger dimensions of the cervical MF and LC muscles for patients were significantly less than that of healthy controls (for both APD and LD; P< 0.05).

CONCLUSION

The results indicated that cervical MF and LC muscles showed higher asymmetry between sides and lesser ratio of smaller size to larger size in patients with CRNP as compared with healthy subjects. Current results confirmed the presence of MF and LC muscles atrophy in subjects with CRNP.

Effectiveness and optimal dosage of exercise training for chronic non-specific neck pain: A systematic review with a narrative synthesis

BACKGROUND

Clinical guidelines make vague recommendations as to exercise training (ET) type and dosage to manage chronic non-specific neck pain (CNSNP).

OBJECTIVE

To synthesise evidence on the effectiveness of different ET programmes to reduce CNSNP and associated disability, and whether dosage affects outcomes.

METHODS

A systematic review and data synthesis was conducted according to a published registered protocol (PROSPERO CRD42018096187). A sensitive topic-based search was conducted of CINAHL, MEDLINE, EMBASE, PEDro, grey literature sources and key journals from inception to 6th January 2020 for randomised controlled trials, investigating ET for CNSNP or disability. Two reviewers independently completed eligibility screening, data extraction, risk of bias assessment (Cochrane Risk of Bias Tool) and rated the overall strength of evidence using Grading of Recommendations Assessment, Development and Evaluation. Data was tabulated for narrative synthesis and grouped by intervention, outcome and time point to compare across studies.

RESULTS

Twenty-six trials from 3990 citations (n = 2288 participants) investigated fifteen ET programmes. High RoB and low sample sizes reduced evidence quality. Clinical heterogeneity prevented meta-analyses. A range of ET programmes reduce pain/disability in the short term (low to moderate evidence). Pillar exercises reduce pain/disability in the intermediate term (low level evidence). Moderate to very large pain reduction is found with ET packages that include motor control + segmental exercises (low to moderate evidence). No high-quality trials investigated long term outcomes. Increased frequency of motor control exercises and progressively increased load of pillar exercise may improve effectiveness.

CONCLUSIONS

Motor control + segmental exercises are the most effective ET to reduce short term pain/disability, but long-term outcomes have not been investigated. Optimal motor control + segmental exercise variables and dosage is unknown and requires clarification. An adequately powered, low RoB trial is needed to evaluate the effectiveness and optimal dosage of motor control + segmental on long term outcomes.

TRIAL REGISTRATION

PROSPERO CRD42018096187.

Does Pain Neuroscience Education and Cognition-Targeted Motor Control Training Improve Cervical Motor Output? Secondary Analysis of a Randomized Clinical Trial

BACKGROUND

In the context of interventions aimed at reducing pain, disability, and maladaptive pain cognitions in chronic neck pain, it is hypothesized that patients who have greater symptom reduction possibly also demonstrate greater improvement in cervical motor output. Therefore, the aim of this study was to examine the effect of pain neuroscience education plus cognition-targeted motor control training on cervical motor output.

METHODS

Impairments in cervical motor output were measured in 64 subjects with chronic neck pain using standardized tests. Cervical muscle strength, cervical mobility, balance, and cervical neuromuscular control were derived. To assess the differences between groups in response to treatment, a random-intercept linear mixed-models analysis, applying a diagonal covariance matrix, was used.

RESULTS

A significant treatment × time interaction effect was found for neuromuscular control of the deep cervical flexors, favoring the experimental treatment at 3 months' follow-up (mean group difference: 1.982; 95% confidence interval 0.779, 3.185; large effect size d = 0.82). Significant main effects of time were found for the neuromuscular capacity of scapulothoracic muscles and for cervical mobility. No significant effects were found for balance, cervical muscle strength, or endurance of cervical flexors.

CONCLUSION

Pain neuroscience education combined with cognition-targeted motor control training is not more effective than biomedically focused education and exercise therapy for improving cervical motor output in people with chronic neck pain. Our findings question the relative importance of factors such as pain, disability, and maladaptive pain cognitions on cervical motor output and the need to address it in treatment.

Can visual feedback on upper trapezius high-density surface electromyography increase time to task failure of an endurance task?

We investigate whether visual feedback on the spatial distribution of upper trapezius muscle activity can prolong time to task failure of sustained shoulder abduction. Surface electromyographic signals were acquired with a 13x5 grid of high-density electromyography (HDEMG) electrodes from the right upper trapezius muscle of 12 healthy volunteers as they performed sustained isometric shoulder abduction at 20% of their maximum voluntary contraction torque (MVC) until volitional exhaustion. Data were collected in two sessions; one with HDEMG visual feedback on the spatial distribution of upper trapezius activity and one without feedback. Although the HDEMG amplitude maps could be voluntarily modified by the participants during the feedback condition (significant shift in the barycenter of activity towards the cranial direction, P = 0.038), this did not influence endurance time (total endurance time with HDEMG feedback: 149.01 ± 77.07 s, no feedback 141.74 ± 60.93 s, P = 0.532). Future studies should assess whether endurance performance can be enhanced by allowing changes in arm position during the task (changing fiber tension-length relationships), by providing a more individual motor strategy, and/or by manipulating the colours used for the HDEMG maps (lighter colours for higher contraction intensities).

Effect of specific deep cervical muscle exercises on functional disability, pain intensity, craniovertebral angle, and neck-muscle strength in chronic mechanical neck pain: a randomized controlled trial

Background

Exercise is known to be an important component of treatment programs for individuals with neck pain. The study aimed to compare the effects of semispinalis cervicis (extensor) training, deep cervical flexor (flexor) training, and usual care (control) on functional disability, pain intensity, craniovertebral (CV) angle, and neck-muscle strength in chronic mechanical neck pain.

Methods

A total of 54 individuals with chronic mechanical neck pain were randomly allocated to three groups: extensor training, flexor training, or control. A Thai version of the Neck Disability Index, numeric pain scale (NPS), CV angle, and neck-muscle strength were measured at baseline, immediately after 6 weeks of training, and at 1- and 3 -month follow-up.

Results

Neck Disability Index scores improved significantly more in the exercise groups than in the control group after 6 weeks training and at 1- and 3-month follow-up in both the exten-sor (P=0.001) and flexor groups (P=0.003, P=0.001, P=0.004, respectively). NPS scores also improved significantly more in the exercise groups than in the control group after 6 weeks’ training in both the extensor (P<0.0001) and flexor groups (P=0.029. In both exercise groups, the CV angle improved significantly compared with the control group at 6 weeks and 3 months (extensor group, P=0.008 and P=0.01, respectively; flexor group, P=0.002 and 0.009, respectively). At 1 month, the CV angle had improved significantly in the flexor group (P=0.006). Muscle strength in both exercise groups had improved significantly more than in the control group at 6 weeks and 1- and 3-month follow-up (extensor group, P=0.04, P=0.02, P=0.002, respectively; flexor group, P=0.002, P=0.001, and 0.001, respectively). The semispinalis group gained extensor strength and the deep cervical flexor group gained flexor strength.

Conclusion

The results suggest that 6 weeks of training in both exercise groups can improve neck disability, pain intensity, CV angle, and neck-muscle strength in chronic mechanical neck pain.

Trial registration

NCT02656030

A systematic review with meta-analysis on functional changes associated with neck pain in adolescents

BACKGROUND

Neck pain (NP) is highly prevalent in young people, but there has been no systematic review synthetizing the functional changes associated with this in adolescents. The aim of the present study was to identify and assess critically the evidence on the functional changes associated with NP in adolescents, specifically for: (a) posture; (b) postural control; (c) range of motion; (d) proprioception; (e) muscle function; and (f) sensory threshold.

METHODS

We searched PubMed, ScienceDirect, Web of Science, PEdro, Scielo, Scopus and Academic Search Premier databases for relevant studies. Two reviewers screened studies for inclusion and assessed the quality of the included studies. One reviewer extracted relevant data from the included studies. A meta-analysis was performed for studies that measured forward head posture (FHP).

RESULTS

Ten studies were included and a total of 15 comparisons for different variables were made. When compared with adolescents without NP, those with NP showed no differences in cervicothoracic posture or FHP. However, statistically significant differences were found for range of motion: weighted mean difference (WMD) from -14.0° (-21.1° to -1.1°) to 9.4° (2.8° to 16.0°); flexor muscle endurance: WMD -11.4 (-21.8 to -0.9) s; extensor muscle endurance: WMD -42.0 (-77.8 to -6.3) s; joint repositioning error for right and left rotation: WMD 1.9° (0.8° to 2.9°) and 2.4° (1.3° to 3.5°), respectively; and pressure pain threshold: WMD from -15.6 (-18.5 to -12.8) to -9.3 (-11.3 to 7.2) N/ cm².

CONCLUSION

There is very limited to limited evidence that there is no difference in posture between adolescents with and without NP, and that there is a difference for range of motion, muscle function, proprioception and pressure pain threshold.

Comparing the effectiveness of integrating ergonomics and motor control to conventional treatment for pain and functional recovery of work-related neck-shoulder pain: A randomized trial

BACKGROUND

Work-related neck and shoulder pain (WRNSP) is highly prevalent among patients who seek physiotherapy treatment. Clinicians may tend to focus on teaching home exercises and provide general advice about workplace improvement. The present study investigates the short- and long-term impact of an intervention approach that emphasizes on integrating the motor control re-education with ergonomic advice.

METHODS

Participants diagnosed with WRNSP (n = 101) were randomly assigned into two groups in this randomized controlled trial. The Ergo-motor Group (EM, n = 51) received an integrated intervention with ergonomic advice/modifications and motor control training individualized for each participant based on their specific work demands. Control Group (CO, n = 50) received treatment for pain relief and general exercises of their necks at a designated physiotherapy clinic. Neck pain intensity and functional outcome measures were assessed before, immediately and 1-year after the 12-week intervention programmes. Global Rating of Change Score was used to evaluate the perceived recovery at 1-year follow-up.

RESULTS

Both groups reported significant reductions in pain and functional disability scores at post-intervention (EM, n = 44; CO, n = 42) and 1-year follow-up (EM, n = 40; CO, n = 38); however, no significant between-group differences were found (p > 0.05). Significantly higher rating in global recovery score was reported in EM group at 1-year follow-up (p < 0.05).

CONCLUSIONS

Intervention integrating ergonomic advice/modification with motor control exercise was found to be equally effective as pain relief and general exercise for pain and functional recovery. However, at 1-year follow-up, such integrated approach resulted in significantly better global recovery perceived by people with WRNSP.

SIGNIFICANCE

Integrating ergonomic intervention and motor control training achieved similar reduction in pain and functional outcomes compared to conventional physiotherapy at post-intervention and at 1-year follow-up, for patients with moderate level of work-related neck-shoulder pain and mild degree of functional disability. The Ergo-motor Group reported significantly better perceived overall recovery at 1-year follow-up.

Feasibility and Acceptability of Technology-Based Exercise and Posture Training in Older Adults With Age-Related Hyperkyphosis: Pre-Post Study

Background

Hyperkyphosis is common among older adults and is associated with multiple adverse health outcomes. Kyphosis-specific exercise and posture training programs improve hyperkyphosis, but in-person programs are expensive to implement and maintain over long periods. It is unclear if a technology-based posture training program disseminated through a mobile phone is a feasible or acceptable alternative to in-person training among older adults with hyperkyphosis.

Objective

The primary purpose was to assess the feasibility of subject recruitment, short-term retention and adherence, and acceptability of a technology-based exercise and posture training program disseminated as video clip links and text messaging prompts via a mobile phone. The secondary purpose was to explore the potential efficacy of this program for kyphosis, physical function, and health-related quality of life in older adults with hyperkyphosis.

Methods

In this 6-week pre-post design pilot trial, we recruited community-dwelling adults aged ≥65 years with hyperkyphosis ≥40° (±5°) and access to a mobile phone. The intervention had two parts: (1) exercise and posture training via video clips sent to participants daily via text messaging, including 6 weekly video clip links to be viewed on the participant’s mobile phone, and (2) text messaging prompts to practice good posture. We analyzed the subject recruitment, adherence, retention, and acceptability of the intervention. Outcomes included change in kyphometer-measured kyphosis, occiput-to-wall (OTW) distance, Short Physical Performance Battery score, Scoliosis Research Society (SRS-30) score, Center for Epidemiological Studies Depression score, and Physical Activity Scale for the Elderly (PASE) score.

Results

A total of 64 potential participants were recruited, 17 were enrolled, and 12 completed postintervention testing at 6 weeks. The average age was 71.6 (SD 4.9) years, and 50% were women. The median adherence to daily video viewing was 100% (range, 14%-100%) and to practicing good posture at least three times per day was 71% (range, 0%-100%). Qualitative evaluation of intervention acceptability revealed that the mobile phone screen was too small for participants to view the videos well and daily prompts to practice posture were too frequent. Kyphosis, OTW distance, and physical activity significantly improved after the 6-week intervention. Kyphosis decreased by 8° (95% CI –12 to –5; P<.001), OTW decreased by 1.9 cm (95% CI –3.3 to –0.7; P=.007), and physical activity measured by PASE increased by 29 points (95% CI 3 to 54; P=.03). The health-related quality of life SRS-30 score increased by 0.11 point (SD 0.19), but this increase was not statistically significant (P=.09).

Conclusions

Technology-based exercise and posture training using video clip viewing and text messaging reminders is feasible and acceptable for a small cohort of older adults with hyperkyphosis. Technology-based exercise and posture training warrants further study as a potential self-management program for age-related hyperkyphosis, which may be more easily disseminated than in-person training.

The influence of musculoskeletal pain disorders on muscle synergies-A systematic review

Background

Musculoskeletal (MSK) pain disorders represent a group of highly prevalent and often disabling conditions. Investigating the structure of motor variability in response to pain may reveal novel motor impairment mechanisms that may lead to enhanced management of motor dysfunction associated with MSK pain disorders. This review aims to systematically synthesize the evidence on the influence of MSK pain disorders on muscle synergies.

Methods

Nine electronic databases were searched using Medical Subject Headings and keywords describing pain, electromyography and synergies. Relevant characteristics of included studies were extracted and assessed for generalizability and risk of bias. Due to the significant heterogeneity, a qualitative synthesis of the results was performed.

Results

The search resulted in a total of 1312 hits, of which seven articles were deemed eligible. There was unclear consistency that pain reduced the number of muscle synergies. There were low consistencies of evidence that the synergy vector (W weights) and activation coefficient (C weights) differed in painful compared to asymptomatic conditions. There was a high consistency that muscle synergies were dissimilar between painful and asymptomatic conditions.

Conclusions

MSK pain alters the structure of variability in muscle control, although its specific nature remains unclear. Greater consistency in muscle synergy analysis may be achieved with appropriate selection of muscles assessed and ensuring consistent achievement of motor task outcomes. Synergy analysis is a promising method to reveal novel understandings of altered motor control, which may facilitate the assessment and treatment of MSK pain disorders.

Temporomandibular disorder and comorbid neck pain: facts and hypotheses regarding pain-induced and rehabilitation-induced motor activity changes

According to the "pain adaptation model", temporomandibular disorder (TMD)-related pain induces a paradoxical activity of masticatory muscles: an agonistic hypoactivity during jaw closing and an antagonistic activity during jaw opening (agonist/antagonist co-activation). However, this model suffers several weaknesses; notably, it does not explain all types of neck muscle activities in neck pain (NP), which is a very prevalent TMD comorbid condition. In NP, neck muscle antagonistic activity is increased, and agonistic activity is decreased as postulated by the pain adaptation model. However, synergistic and compensatory activity may occur and agonistic activity may be unchanged or even increased as postulated within the "vicious cycle theory". Thus, both theories would apply partly as outlined currently in musculoskeletal disorders (MSD). Besides pain, psychological stress may also induce motor dysfunction in TMD and NP. In NP, rehabilitation may increase agonistic activity and decrease compensatory activity and antagonistic activity, thus inducing a switch from agonist/antagonist co-activation towards reciprocal inhibition. Thus, rehabilitation-induced motor activity changes constitute a new research field that should improve MSD therapeutics. Additionally, immature tongue function (so-called infantile swallow) might be connected to TMD where low agonistic activity of masticatory muscles would be compensated by facial muscle hyperactivity during oropharyngeal phase of deglutition.

Relationship between knee alignment in asymptomatic subjects and flexibility of the main muscles that are functionally related to the knee

Objective To assess the relationship between static frontal knee alignment in asymptomatic subjects and flexibility of the main muscles functionally related to the knee. Methods A descriptive cross-sectional study was performed in 33 healthy adults (19-31 years). The frontal knee angle (valgus/varus angle) was measured by photogrammetry and it was measured in the lateral side. Therefore, high values were assigned for genu varum and low values for genu valgum. Iliopsoas, gluteus maximus and medius, rectus femoris, biceps femoris, vastus of the quadriceps, and gastrocnemius muscles were stretched. Muscles were classified as normal, reflex hypomobile, or structural hypomobile. Results Women had significantly greater valgus than did men (right angle, women: 174.41°/men: 177.41°; left angle, women: 174.20°/men: 178.70°). The right frontal plane knee angle was higher in women with structural hypomobile vastus. The left frontal plane knee angle was higher in women with structural hypomobile iliopsoas. No relationships were found in men. Conclusions A tighter vastus of the quadriceps and tighter iliopsoas are related to greater genu varum in adult women. Stretching the vastus of the quadriceps and iliopsoas when there is a tendency for excess varus in the knee, to prevent overuse injury or early osteoarthritis, might be clinically relevant.

The influence of cervical movement on eye stabilization reflexes: a randomized trial

To investigate the influence of the amount of cervical movement on the cervico-ocular reflex (COR) and vestibulo-ocular reflex (VOR) in healthy individuals. Eye stabilization reflexes, especially the COR, are changed in neck pain patients. In healthy humans, the strength of the VOR and the COR are inversely related. In a cross-over trial the amplitude of the COR and VOR (measured with a rotational chair with eye tracking device) and the active cervical range of motion (CROM) was measured in 20 healthy participants (mean age 24.7). The parameters were tested before and after two different interventions (hyperkinesia: 20 min of extensive active neck movement; and hypokinesia: 60 min of wearing a stiff neck collar). In an additional replication experiment the effect of prolonged (120 min) hypokinesia on the eye reflexes were tested in 11 individuals. The COR did not change after 60 min of hypokinesia, but did increase after prolonged hypokinesia (median change 0.220; IQR 0.168, p = 0.017). The VOR increased after 60 min of hypokinesia (median change 0.155, IQR 0.26, p = 0.003), but this increase was gone after 120 min of hypokinesia. Both reflexes were unaffected by cervical hyperkinesia. Diminished neck movements influences both the COR and VOR, although on a different time scale. However, increased neck movements do not affect the reflexes. These findings suggest that diminished neck movements could cause the increased COR in patients with neck complaints.

Eye stabilization reflexes in traumatic and non-traumatic chronic neck pain patients

BACKGROUND

Many chronic neck pain patients experience problems with vision. These problems are possibly induced by deviations of the eye stabilization reflexes. It is not known whether these eye reflex alterations occur both in traumatic and non-traumatic neck pain patients.

OBJECTIVE

To investigate if the cervico-ocular reflex (COR) and the vestibulo-ocular reflex (VOR) are changed in tertiary care patients with prolonged, chronic neck pain with various origin of complaints.

DESIGN

Cross sectional study.

METHODS

Ninety-one chronic neck pain patients were subdivided into three groups by origin of complaints, and compared with healthy controls. COR and VOR gains were measured with an infrared eye tracking device with the subject sitting on a rotating chair in a darkened room and with the head fixed.

RESULTS

Neck pain patients had a higher COR gain (median 0.41, IQR 0.289) compared with healthy controls (median 0.231, IQR 0.179). The mean COR gain did not differ between the three patient groups (Whiplash Associated Disorders 0.444 (SD 0.221); traumatic 0.397 (SD0.205); non-traumatic 0.468 (SD0.236)). There was no difference in VOR gain between the groups.

CONCLUSION

Chronic neck pain patients, who already received primary care, still have an elevated cervico-ocular reflex. The origin of complaints did not seem to be associated with this deviant oculomotor behavior.

Does Deep Cervical Flexor Muscle Training Affect Pain Pressure Thresholds of Myofascial Trigger Points in Patients with Chronic Neck Pain? A Prospective Randomized Controlled Trial

Background. We need to understand more about how DNF performs in different contexts and whether it affects the pain threshold over myofascial trigger points (MTrPs). Purpose. The objectives were to investigate the effect of neck muscles training on disability and pain and on pain threshold over MTrPs in people with chronic neck pain. Methods. Patients with chronic neck pain were eligible for participation with a Neck Disability Index (NDI) score of over 5/50 and having at least one MTrP on either levator scapulae, upper trapezoid, or splenius capitis muscle. Patients were randomly assigned into either DNF training, superficial neck muscle exercise, or advice group. Generalized linear model (GLM) was used to detect differences in treatment groups over time. Results. Out of 67 participants, 60 (47 females, mean age: 39.45 ± 12.67) completed the study. Neck disability and neck pain were improved over time between and within groups (p < 0.05). However, no differences were found within and between the therapeutic groups (p < 0.05) in the tested muscles' PPTs and in cervicothoracic angle over a 7-week period. Conclusion. All three groups improved over time. This infers that the pain pathways involved in the neck pain relief are not those involved in pain threshold.

Eye movements in patients with Whiplash Associated Disorders: a systematic review

Background

Many people with Whiplash Associated Disorders (WAD) report problems with vision, some of which may be due to impaired eye movements. Better understanding of such impaired eye movements could improve diagnostics and treatment strategies.

This systematic review surveys the current evidence on changes in eye movements of patients with WAD and explains how the oculomotor system is tested.

Methods

Nine electronic data bases were searched for relevant articles from inception until September 2015. All studies which investigated eye movements in patients with WAD and included a healthy control group were screened for inclusion. Qualifying studies were retrieved and independently assessed for methodological quality using the Methodology Checklists provided by the Scottish Intercollegiate Guidelines Network.

Results

Fourteen studies out of 833 unique hits were included. Ten studies reported impaired eye movements in patients with WAD and in four studies no differences compared to healthy controls were found. Different methods of eye movement examination were used in the ten studies: in five studies, the smooth pursuit neck torsion test was positive, in two more the velocity and stability of head movements during eye-coordination tasks were decreased, and in another three studies the cervico-ocular reflex was elevated.

Conclusions

Overall the reviewed studies show deficits in eye movement in patients with WAD, but studies and results are varied. When comparing the results of the 14 relevant publications, one should realise that there are significant differences in test set-up and patient population. In the majority of studies patients show altered compensatory eye movements and smooth pursuit movements which may impair the coordination of head and eyes.

Computer Vision Based Automatic Extraction and Thickness Measurement of Deep Cervical Flexor from Ultrasonic Images

Deep Cervical Flexor (DCF) muscles are important in monitoring and controlling neck pain. While ultrasonographic analysis is useful in this area, it has intrinsic subjectivity problem. In this paper, we propose automatic DCF extractor/analyzer software based on computer vision. One of the major difficulties in developing such an automatic analyzer is to detect important organs and their boundaries under very low brightness contrast environment. Our fuzzy sigma binarization process is one of the answers for that problem. Another difficulty is to compensate information loss that happened during such image processing procedures. Many morphologically motivated image processing algorithms are applied for that purpose. The proposed method is verified as successful in extracting DCFs and measuring thicknesses in experiment using two hundred 800 × 600 DICOM ultrasonography images with 98.5% extraction rate. Also, the thickness of DCFs automatically measured by this software has small difference (less than 0.3 cm) for 89.8% of extracted DCFs.

Novel insights into the interplay between ventral neck muscles in individuals with whiplash-associated disorders

Chronic whiplash-associated disorder (WAD) is common after whiplash injury, with considerable personal, social, and economic burden. Despite decades of research, factors responsible for continuing pain and disability are largely unknown, and diagnostic tools are lacking. Here, we report a novel model of mechanical ventral neck muscle function recorded from non-invasive, real-time, ultrasound measurements. We calculated the deformation area and deformation rate in 23 individuals with persistent WAD and compared them to 23 sex- and age-matched controls. Multivariate statistics were used to analyse interactions between ventral neck muscles, revealing different interplay between muscles in individuals with WAD and healthy controls. Although the cause and effect relation cannot be established from this data, for the first time, we reveal a novel method capable of detecting different neck muscle interplay in people with WAD. This non-invasive method stands to make a major breakthrough in the assessment and diagnosis of people following a whiplash trauma.

Experimental Muscle Pain Impairs the Synergistic Modular Control of Neck Muscles

A motor task can be performed via different patterns of muscle activation that show regularities that can be factorized in combinations of a reduced number of muscle groupings (also referred to as motor modules, or muscle synergies). In this study we evaluate whether an acute noxious stimulus induces a change in the way motor modules are combined to generate movement by neck muscles. The neck region was selected as it is a region with potentially high muscular redundancy. We used the motor modules framework to assess the redistribution of muscular activity of 12 muscles (6 per side) in the neck region of 8 healthy individuals engaged in a head and neck aiming task, in non-painful conditions (baseline, isotonic saline injection, post pain) and after the injection of hypertonic saline into the right splenius capitis muscle. The kinematics of the task was similar in the painful and control conditions. A general decrease of activity was noted for the injected muscle during the painful condition together with an increase or decrease of the activity of the other muscles. Subjects did not adopt shared control strategies (motor modules inter subject similarity at baseline 0.73±0.14); the motor modules recorded during the painful condition could not be used to reconstruct the activation patterns of the control conditions, and the painful stimulus triggered a subject-specific redistribution of muscular activation (i.e., in some subjects the activity of a given muscle increased, whereas in other subjects it decreased with pain). Alterations of afferent input (i.e., painful stimulus) influenced motor control at a multi muscular level, but not kinematic output. These findings provide new insights into the motor adaptation to pain.

Neck Pain in Changi General Hospital: An Observational Study

Introduction:

The aim of this study is to describe the profile of neck pain patients in the local population and to investigate the efficacy of physiotherapy management of neck pain.

Methods:

A retrospective study was done with neck pain patients who have attended the Musculoskeletal Physiotherapy Clinic at Changi General Hospital from August 2010 to September 2011. The following data was collected from each patient: age, gender, occupation, mechanism of injury, chronicity, posture type, symptom location, physiotherapy management, number of treatment sessions, pain and functional scores pre- and post-therapy. The patients were also categorised according to International Classification of Functioning, Disability and Health (ICF) categories and observed for clinical profiles.

Results:

Ninety-one records were screened. The majority of patients (79%) were aged between 35–65 years. The condition was slightly more prevalent in males (55%) than females (45%). Seventy per cent of the patients had non-traumatic and 30% traumatic onset. The majority (69%) had chronic neck pain; 25% had sub-acute and 6% acute neck pain. The majority of patients had slouched sitting posture (84%). Almost half of the neck patients (48.9%) had unilateral neck pain; 20.2% had central neck pain, 16% had neck pain with shoulder pain, 12.8% had neck pain with radiating pain and 2.1% had neck pain with headache. The categorisation showed 51.1% reported neck pain with movement co-ordination, 30.9% with mobility deficit, 12.8% with radiating pain and 5.2% with headache. The multi-modal method showed significant improvement on the pain scale (p >0.001) within an average of 4.3 physiotherapy sessions.

Conclusion:

Neck pain is common in Singapore, affecting the middle-aged population. Many of these cases presented chronic neck pain, with no trauma involved at symptom onset. A slouched sitting posture was observed most commonly amongst patients with neck pain. Our study indicates that the classification system is valid for clinical use. Patients with headache registered a higher pain intensity than those in other categories. The multi-modal approach is effective in the treatment of neck pain.

The relevance of scapular dysfunction in neck pain: a brief commentary

Synopsis Though our understanding of motor disorders and mechanical neck pain has advanced, the role of scapular dysfunction in mechanical neck pain remains enigmatic. The biomechanical interdependence between the neck and scapula and the potentially deleterious consequences of scapular dysfunction in the cervical region are biomechanically plausible. Yet the relevance of observed scapular dysfunction in patients with neck pain is still inadequately explained by research. However, studies investigating the association between scapular function and neck pain are beginning to emerge. The purpose of this paper was to review the current knowledge of this topic and consider the implications for clinical practice. Level of Evidence Therapy, level 5.

The intra- and inter-rater reliability of five clinical muscle performance tests in patients with and without neck pain

Background

This study investigates the reliability of muscle performance tests using cost- and time-effective methods similar to those used in clinical practice. When conducting reliability studies, great effort goes into standardising test procedures to facilitate a stable outcome. Therefore, several test trials are often performed. However, when muscle performance tests are applied in the clinical setting, clinicians often only conduct a muscle performance test once as repeated testing may produce fatigue and pain, thus variation in test results. We aimed to investigate whether cervical muscle performance tests, which have shown promising psychometric properties, would remain reliable when examined under conditions similar to those of daily clinical practice.

Methods

The intra-rater (between-day) and inter-rater (within-day) reliability was assessed for five cervical muscle performance tests in patients with (n = 33) and without neck pain (n = 30). The five tests were joint position error, the cranio-cervical flexion test, the neck flexor muscle endurance test performed in supine and in a 45°-upright position and a new neck extensor test.

Results

Intra-rater reliability ranged from moderate to almost perfect agreement for joint position error (ICC ≥ 0.48-0.82), the cranio-cervical flexion test (ICC ≥ 0.69), the neck flexor muscle endurance test performed in supine (ICC ≥ 0.68) and in a 45°-upright position (ICC ≥ 0.41) with the exception of a new test (neck extensor test), which ranged from slight to moderate agreement (ICC = 0.14-0.41). Likewise, inter-rater reliability ranged from moderate to almost perfect agreement for joint position error (ICC ≥ 0.51-0.75), the cranio-cervical flexion test (ICC ≥ 0.85), the neck flexor muscle endurance test performed in supine (ICC ≥ 0.70) and in a 45°-upright position (ICC ≥ 0.56). However, only slight to fair agreement was found for the neck extensor test (ICC = 0.19-0.25).

Conclusions

Intra- and inter-rater reliability ranged from moderate to almost perfect agreement with the exception of a new test (neck extensor test), which ranged from slight to moderate agreement. The significant variability observed suggests that tests like the neck extensor test and the neck flexor muscle endurance test performed in a 45°-upright position are too unstable to be used when evaluating neck muscle performance.

Cervical musculoskeletal impairments and temporomandibular disorders

Objectives

The study of cervical muscles and their significance in the development and perpetuation of Temporomandibular Disorders has not been elucidated. Thus this project was designed to investigate the association between cervical musculoskeletal impairments and Temporomandibular Disorders.

Material and Methods

A sample of 154 subjects participated in this study. All subjects underwent a series of physical tests and electromyographic assessment (i.e. head and neck posture, maximal cervical muscle strength, cervical flexor and extensor muscles endurance, and cervical flexor muscle performance) to determine cervical musculoskeletal impairments.

Results

A strong relationship between neck disability and jaw disability was found (r = 0.82). Craniocervical posture was statistically different between patients with myogenous Temporomandibular Disorders (TMD) and healthy subjects. However, the difference was too small (3.3º) to be considered clinically relevant. Maximal cervical flexor muscle strength was not statistically or clinically different between patients with TMD and healthy subjects. No statistically significant differences were found in electromyographic activity of the sternocleidomastoid or the anterior scalene muscles in patients with TMD when compared to healthy subjects while executing the craniocervical flexion test (P = 0.07). However, clinically important effect sizes (0.42 - 0.82) were found. Subjects with TMD presented with reduced cervical flexor as well as extensor muscle endurance while performing the flexor and extensor muscle endurance tests when compared to healthy individuals.

Conclusions

Subjects with Temporomandibular Disorders presented with impairments of the cervical flexors and extensors muscles. These results could help guide clinicians in the assessment and prescription of more effective interventions for individuals with Temporomandibular Disorders.

Dry needling - peripheral and central considerations

Dry needling is a common treatment technique in orthopedic manual physical therapy. Although various dry needling approaches exist, the more common and best supported approach targets myofascial trigger points. This article aims to place trigger point dry needling within the context of pain sciences. From a pain science perspective, trigger points are constant sources of peripheral nociceptive input leading to peripheral and central sensitization. Dry needling cannot only reverse some aspects of central sensitization, it reduces local and referred pain, improves range of motion and muscle activation pattern, and alters the chemical environment of trigger points. Trigger point dry needling should be based on a thorough understanding of the scientific background of trigger points, the differences and similarities between active and latent trigger points, motor adaptation, and central sensitize application. Several outcome studies are included, as well as comments on dry needling and acupuncture.

Can a functional postural exercise improve performance in the cranio-cervical flexion test?--a preliminary study

Deep cervical flexor (DCF) muscle impairment is common in patients with neck pain. Retraining function is often commenced with a motor relearning approach, requiring the patient to practice and hold a cranio-cervical flexion position in supine lying. Motor relearning requires multiple repetitions which is difficult to achieve if only exercising in supine. This preliminary study investigated the effects of training the DCF with a functional exercise: assumption of an upright lumbo-pelvic and spinal postural position, adding a neck lengthening manoeuvre. The exercise effect was evaluated by changes in sternocleidomastoid (SCM) muscle activity in the cranio-cervical flexion test (CCFT). Twenty subjects with neck pain were randomly assigned to an exercise or control group. The exercise group trained for two weeks. Pre and post-intervention, electromyographic (EMG) signals were recorded from the SCM muscles during the five stages of the CCFT. Results indicated that the exercise improved performance. SCM EMG signal amplitudes decreased across all CCFT stages, albeit significant only at the first and third stages of the test; 22 mmHg (p = 0.043) and 26 mmHg (p = 0.003). No differences were evident in the control group (all p > 0.05). There was no difference between groups for pain and disability measures. This initial study indicates that a postural exercise, convenient to perform during the working day, improves the pattern of SCM muscle activity in the CCFT. Whilst further research is necessary, these observations suggest the worth of such an exercise to augment other training in the rehabilitation of patients with neck pain.