Alterations in cervical muscle activity in functional and stressful tasks in female office workers with neck pain

Cervical extensor muscle activity during neck tasks in individuals with and without neck pain: A systematic review

BACKGROUND

In the context of neck pain, neck muscle activity adapts through diverse regional coordination modifications during tasks. Although patterns of cervical flexor muscle impairment are well-documented, patterns in the cervical extensor muscles are less clear, hindering assessment and treatment. Despite studies revealing adaptations in the cervical extensor muscles, outcome measure heterogeneity complicates interpretation, particularly between superficial and deep muscles. To address this, we conducted a systematic review comparing neck extensor muscle activity between symptomatic and asymptomatic groups during tasks, aiming to inform clinical practice.

OBJECTIVES

To compare the cervical extensor muscle activity during neck tasks between symptomatic and asymptomatic groups, using complementary examination tools.

METHODS

Up to January 2024, experimental studies assessing cervical extensor muscle activity during neck tasks in adults with idiopathic or traumatic neck pain, or cervicogenic headache compared to healthy controls were included. Study selection involved 2 blinded reviewers. Electronic databases (Medline, Scopus, and Embase), reference lists, and relevant reviews were screened. Data extraction focused on the results of the between-group motor activity comparisons. Critical appraisal used the JBI appraisal checklist for analytical cross-sectional studies.

RESULTS

Twenty-three studies met the inclusion criteria, involving 932 participants and reporting 170 comparative assessments of 8 muscle groups, encompassing 4 main motor activity outcomes: recruitment, timing, fatigue, and directional activation. Significant differences were noted for motor recruitment in 51 % of comparisons, for timing in 35 %, and fatigue in 33 %, with consistent differences in directional activation. Impaired activity in individuals with neck pain compared to those without was found in 47 % of comparisons for superficial muscles and 65 % for deep muscles.

CONCLUSIONS

Motor activity adaptations during neck tasks appear to be unpredictable in individuals with neck pain, with a tendency for change in the deep cervical extensor muscles. Further high-quality studies are needed to confirm these findings, considering various contraction parameters, multiple muscle analyses, and several motor activity outcomes.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Review CRD42022285864.

Association among clinical severity indicators, psychological health status and elastic properties of neck muscles in patients with chronic mechanical neck pain

BACKGROUND

Since objective stifness measures are not consistent with the patients' perception and its correlation with the clinical severity of neck pain is not clear, novel studies assessing the clinical relevance of muscle stiffness are needed.

OBJECTIVES

To analyze the correlation among psychological factors, clinical severity indicators, and muscle stiffness in neck muscles in patients with chronic mechanical neck pain, and compare these factors with asymptomatic controls.

METHODS

A cross-sectional observational study was conducted. Participants included cases with chronic neck pain and asymptomatic controls, assessed for muscle stiffness using shear wave elastography, psychological health (anxiety and kinesiophobia), and clinical severity. Data analysis involved correlation matrices and comparison between groups.

RESULTS

Although no significant differences in levator scapulae stiffness were observed between groups (p > 0.05), patients exhibited significantly increased stiffness in the anterior scalene and cervical multifidus muscles (p = 0.009 and p = 0.040, respectively). STAI scores were significantly higher in patients for both subscales (STAI-S p = 0.002 and STAI-T p < 0.001), but no kinesiophobic behaviors differences were found (p > 0.05). Significant correlations between pain chronicity, intensity, disability, and psychological factors were confirmed. Notably, the levator scapulae stiffness was positively associated with disability, anxiety, and kinesiophobia (all p < 0.01). However, the anterior scalene and cervical multifidus stiffness, even if significantly associated with demographic factors (p < 0.05), were not associated with clinical or psychological outcomes.

CONCLUSION

The findings underscore the intertwined nature of psychological factors and muscle stiffness in chronic neck pain, suggesting the need for integrated approaches in treatment that consider both physical and psychological dimensions.

Electromyographic Activity of Cervical Muscles in Patients with Neck Pain and Changes After Dry Needling: A Narrative Review

Neck pain can be associated with specific conditions, such as neurological disorders, vascular or inflammatory diseases, fractures, herniated discs, etc. However, the majority of neck pain cases cannot be attributed to a specific cause. The objective of this review is to describe the muscle dysfunctions associated with neck pain, as measured by electromyography, and to determine the effectiveness of dry needling in improving these muscular dysfunctions. The research was conducted using the following databases: PubMed, Alcorze, and Google Scholar. The next conclusions have been extracted after the revision of the 65 selected manuscripts. The current scientific evidence supports electromyographic pathological findings in individuals with chronic neck pain, especially during general upper limb movement, repetitive work, violin playing, cervical force, and cervical movement tasks. Dry needling applied to an active myofascial trigger point in the upper trapezius can be suggested as an intervention to enhance the performance in the cranio-cervical flexion. Dry needling applied to latent myofascial trigger points in the upper trapezius after typing tasks in healthy subjects resulted in decreased upper trapezius activity and fatigue in the short term. In women with trapezius myalgia, dry needling applied to the upper trapezius led to a lower increase in electromyography activity compared to no intervention.

Investigating cervical flexion-relaxation ratio in subjects with cervical lateral spinal stenosis compared with asymptomatic controls: A case control study

INTRODUCTION

The cervical flexion-relaxation ratio (FRR) is known as a quantitative measure of the ability of the cervical extensor muscles to relax during the full flexion of the cervical spine. Compared with subjects suffering from non-specific neck pain, the changes occurring in the pattern of the neck muscles' functions in cases with cervical spinal stenosis are not yet well understood. Therefore, this study aimed to compare cervical FRR in subjects with cervical lateral spinal stenosis and asymptomatic controls.

METHODS

In total, 25 subjects with cervical lateral spinal stenosis (aged 44.7 ± 10.4) and 25 asymptomatic individuals (aged 44.3 ± 10.8) were included in this study. These participants performed full-neck flexion, and at the same time, the electrical activity of the cervical erector spinae (CES) muscles was recorded bilaterally. Cervical FRR was further calculated by analyzing the electromyographic data recorded for each muscle.

RESULTS

The mean cervical FRR was significantly lower (P = 0.015) and the FRR asymmetry (ΔFRR) was significantly higher (P = 0.003) in the patients than asymptomatic controls. In addition, the cervical FRR of the involved side was significantly lower in the subjects with cervical pain compared with that in the non-involved one (P = 0.004). There was also a significant difference in the cervical extension (CE) angle between both study groups (P < 0.001), while the cervical flexion (CF) angle was not different (P = 0.25).

CONCLUSION

According to the study results, FRR and its asymmetry in the subjects with cervical lateral spinal stenosis were significantly different from that in asymptomatic controls and the CE angle declined in these subjects.

Dry needling in the management of chronic tension-type headache associated with levator scapulae syndrome: A case report

Key Clinical Message

The use of DN to the muscular trigger points and distal periosteal enthesis of the levator scapulae may be a useful adjunct intervention within a multi-modal plan of care for the management of work-related chronic tension-type headaches associated with LSS.

Abstract

Chronic tension-type headaches (CTTH) have a lifetime prevalence of 42% and account for more lost workdays than migraine headaches. Dry needling (DN) is being increasingly used by physical therapists in the management of CTTH; however, to date, the supporting evidence is limited. The purpose of this case report was to describe how three sessions of DN targeting myofascial trigger points in the levator scapulae (LS) muscle and its distal enthesis was used to treat a 63-year-old male patient who presented with work-related CTTH associated with levator scapulae syndrome (LSS). The patient was treated for five visits over the course of 2 months. At discharge and 6-month follow-up, the patient reported full resolution of symptoms. Self-report outcomes included the numeric pain rating scale and the Neck Disability Index. The use of DN to the LS muscle and its distal enthesis may be a valuable addition to a multi-modal plan of care in the treatment of work-related CTTH associated with LSS.

Exercise-induced hypoalgesia in chronic neck pain: A narrative review

Chronic neck pain (CNP) is a worldwide health problem with several risk factors. One of the most widely used treatments for managing this condition is therapeutic exercise, which could generate a response called exercise-induced hypoalgesia (EIH). There is no consensus on the best exercise modality to induce hypoalgesia. Therefore, this review aims to analyze and synthesize the state-of-the-art about the hypoalgesic effect of exercise in subjects with CNP. We included articles on EIH and CNP in patients older than 18 years, with pain for more than three months, where the EIH response was measured. Articles that studied CNP associated with comorbidities or measured the response to treatments other than exercise were excluded. The studies reviewed reported variable results. Exercise in healthy subjects has been shown to reduce indicators of pain sensitivity; however, in people with chronic pain, the response is variable. Some investigations reported adverse effects with increased pain intensity and decreased pain sensitivity, others found no clinical response, and some even reported EIH with decreased pain and increased sensitivity. EIH is an identifiable, stimulable, and helpful therapeutic response in people with pain. More research is still needed on subjects with CNP to clarify the protocols and therapeutic variables that facilitate the EIH phenomenon. In addition, it is necessary to deepen the knowledge of the intrinsic and extrinsic factors that influence EIH in people with CNP.

Axioscapular and neck extensor muscle behavior during isometric shoulder exertions in patients with nonspecific neck pain with and without a scapular downward rotation posture

BACKGROUND

A common observation in persons with neck pain is scapular downward rotation (SDR) with altered muscle behavior. Evidence of changes in axioscapular muscles in neck pain patients remains inconclusive, which may reflect population heterogeneity in previous studies.

RESEARCH QUESTION

Are there differences in behavior of the axioscapular (upper trapezius: UT, lower trapezius: LT and serratus anterior: SA) and neck extensor (NE) muscles during isometric shoulder tasks in patients with neck pain with SDR, patients with no scapular dysfunction and healthy controls?

METHODS

Sixty participants with nonspecific neck pain (30 with SDR and 30 without scapular dysfunction) and 30 controls were recruited. Electromyographic signals were recorded unilaterally from the UT, LT, SA and NE during different isometric shoulder tasks (30° flexion, 30°abduction and 30°external rotation) at 20%, 50% and 100% maximal voluntary contraction (MVC). Activity of UT, LT, SA and NE was normalized with respect to reference contractions. The UT/LT, UT/SA and LT/SA ratios were calculated for each task.

RESULTS

The neck pain group with SDR had increased UT activity in 30°flexion (20%MVC) and 30°abduction (20% and 50%MVC) compared to the neck pain and control groups without scapular dysfunction (p < 0.05). There were no between group differences in LT and SA activity (p > 0.05). The neck pain groups had greater NE activity in all tasks (p < 0.001). Finally, the neck pain group with SDR had higher UT/LT and UT/SA ratios in a few tasks at low force levels (p ≤ 0.01).

SIGNIFICANCE

Greater UT activity and UT/LT and UT/SA ratios during particularly low force isometric shoulder tasks suggest that SDR is associated with altered axioscapular motor control. Greater NE activity in both neck pain groups suggests altered motor control related to neck pain. Changes in the NE and UT behavior should be considered in management of patients with neck pain with observable SDR.

A comparison of muscle activity, posture and body discomfort during the use of different computer screen sizes

This study aims to compare changes in neck angles, muscle activities, ergonomic risk and body discomfort caused by use of two different computer screen sizes. The 36 female users who participated used displays with 46.99 and 58.42-cm screen sizes and were assessed for craniocervical angle (CCA), craniovertebral angle (CVA), upper trapezius (UT) and sternocleidomastoid (SCM) muscle activity, ergonomic risk and body discomfort for a duration of 1 h. The results showed there were no significant differences when comparing usage between both computer screen sizes (p > 0.05). However, there were significant differences in the CCA, UT muscle activity and body discomfort when comparing before and after usage for both computer screen sizes (p < 0.05). The results indicate that computer users can select different screen sizes for working but should be concerned with neck angle, muscle activity and body discomfort when using for long periods of time.

Effects of typing positions on the upper trapezius and neck extensor muscles electromyography in office employees: A single-blind cross-sectional study

BACKGROUND

Holding incorrect postures over a long period could lead to chronic nonspecific neck pain (CNNP) in office employees.

OBJECTIVE

The present study aimed to evaluate the effects of different typing positions on the activity of the neck extensor and upper trapezius (UT) muscles of office employees diagnosed with CNNP.

METHODS

This assessor-blinded cross-sectional study was performed on 22 female subjects with the mean age of 39.95±5.30 years. The neck extensors and UT muscle activities of the participants were assessed in the upright, forward, and slouching postures by electromyography (EMG). In addition, neck proprioception and the performance of the cervical stabilizer muscles were evaluated using an inclinometer and biofeedback pressure unit, respectively.

RESULTS

A significant difference was observed between the cervical erector spine (CES) and UT muscle activities in the upright, forward, and slouching typing positions (P < 0.05). In addition, a difference was observed between the upright and slouching postures in these muscles. A positive correlation was denoted between CES muscle activity in the slouching and forward postures and the activation index of neck muscles (P < 0.05). Furthermore, a significant, negative correlation was observed between the UT muscle activity in the slouching posture and neck proprioception (P < 0.05). A positive correlation was also noted between the pain index and repositioning error rates (P < 0.05).

CONCLUSION

CES muscle activity increased in a forward head posture, which could damage neck proprioception through causing early fatigue and stimulating a cumulative damage cycle.

The Importance of Optimal Gaze Direction on Deep Neck Flexor Activation in Chronic Neck Pain

Chronic neck pain (CNP) patients have weak deep neck flexors (DNF) and a hyperactive sternocleidomastoid (SCM). The cranio-cervical flexion test (CCFT) promotes activation of the DNF and decreases activity of the SCM, promoting pain recovery, but research suggests SCM activation increases with increasing gaze direction. We aimed to investigate how DNF and SCM activation varies according to gaze direction in the CCFT, and to prescribe the appropriate gaze direction for CNP. Twenty-eight CNP subjects had their maximum strength pressure level determined by CCFT for strength (20-~30 mmHg) and at each of the measured pressures, DNF and SCM thickness in each of four gaze directions (0°, 20°, 40°, and 60°) was measured by ultrasound imaging. The DNF to SCM ratio varied significantly according to gaze direction (p < 0.05), with gaze directions of 20° and 0° being significantly different from 40° (p < 0.05). Although there was no significant difference in DNF activation according to gaze direction, there was in SCM activation (p < 0.05), with SCM 60° significantly different from SCM 20° and SCM 40° (p < 0.05). In order to increase DNF activation efficiency during the CCFT, SCM activation should be controlled, and a gaze direction below 20° is the most efficient. This can inform DNF training of CNP patients in a clinical environment.

A field study on spinal postures and postural variations during smartphone use among university students

This field study compared the real-time spinal movements and postural variations during smartphone-use versus non-use in university students. Ten males and eight females (mean age of 21.5 ± 2.6 years) participated, with similar daily phone use time between the two sexes. Five inertial motion sensors were attached to the cervical, thoracic and lumbar spinal regions, and kinematics was recorded for 3 h while participants went about their usual academic activities within the university campus. Significantly greater degrees of cervical and upper thoracic flexion were adopted during phone use versus non-use time (p < 0.01). There were also significantly greater frequency of postural variations (zero crossing per min) in all spinal regions in the sagittal plane (all p < 0.05), and in some of the movements in transverse and frontal planes comparing phone use vs non-use. The postural variables also showed some significant correlations with self-reported pre-existing neck and upper back pain scores.

Alterations in the 3-dimensional scapular orientation in patients with non-specific neck pain

BACKGROUND

Although it is thought that there is a relationship between neck pain and scapular dysfunction, there are controversial results and no clear information in the literature regarding this issue. This study aimed to investigate the alterations in the 3-Dimensional scapular orientation on patients with non-specific neck pain.

METHOD

Thirty-four patients with chronic non-specific neck pain [age, 29.1 (5) years; height, 165.3 (6.1) centimeters; weight, 62.1 (9.6) kilogram] and 29 healthy controls [age, 28.2 (3.3) years; height, 166.8 (8.1) centimeters; weight, 60.9 (8.5) kilogram] were included in the study. 3-Dimensional scapular kinematics were obtained during arm elevation and lowering trials in the sagittal, scapular, and frontal planes.

FINDINGS

Compared to healthy controls, the patients with neck pain demonstrated significantly reduced upward scapular rotation on both the dominant and non-dominant sides in all three planes. Patients with neck pain had increased internal rotation in the sagittal and frontal planes on the dominant side and increased external rotation in the frontal plane on the non-dominant side. No difference was observed between groups considering posterior scapular tilt.

INTERPRETATION

There are alterations in the 3-Dimensional scapular orientations in patients with chronic non-specific neck pain compared to healthy controls. Therefore, the scapular control may also be examined in patients with neck pain and it can be included in the rehabilitation program if needed.

Trapezius muscle activity variation during computer work performed by individuals with and without neck-shoulder pain

This study aimed at determining the extent to which individuals with neck-shoulder pain and non-symptomatic individuals differ in muscle activation patterns, when performing computer work, as quantified by exposure variation analysis (EVA). As a secondary aim, we also aimed to quantify the day-to-day reliability of EVA variables describing trapezius muscle activation in a non-symptomatic control group. Thirteen touch-typing computer users (pain: n = 5, non-symptomatic: n = 8) completed three pre-selected computer tasks in the laboratory. Upper trapezius muscle activity was recorded using electromyography and analyzed using EVA with five amplitude and five duration categories. Individuals with neck-shoulder pain spent less time at low amplitudes and exhibited longer uninterrupted periods of muscle activation compared to their non-symptomatic counterparts. Thus, non-symptomatic workers tended to switch between exposure levels more often than individuals with pain. For a majority of EVA variables, ICCs ranged from 0.6 to 0.9, and between-days coefficients of variation were between 0.4 and 2.2.

Reliability of a Method to Measure Neck Surface Electromyography, Kinematics, and Pain Occurrence in Participants With Neck Pain

OBJECTIVE

To investigate the reliability of a novel method to measure neck surface electromyography (SEMG), kinematics, and pain during active movements in participants with neck pain.

METHODS

This test-retest study evaluated 23 participants with chronic neck pain. Each was measured twice within a single session. Three-dimensional kinematics and SEMG were recorded in 10° increments during forward and side flexion, extension, and rotation of the neck. Neck position during pain occurrence was also measured.

RESULTS

Intraclass correlation coefficients were >0.80 for 96% and 100% of SEMG and kinematic data, respectively. The percentage of standard error of the measurement (SEM) values were <25% for 91% of all SEMG measures; most were <15%, and some were <10%. For ranges of motion in the primary plane, percentage of SEM values were all <6% (SEM 1°-3°). Intraclass correlation coefficients for neck position during pain occurrence were all >0.60, except for right rotation (0.48) (SEM values 2°-8°). Pain occurred approximately 59% to 75% into the total range of motion and persisted to its end.

CONCLUSIONS

This methodology showed good reliability. It may be suitable for neck pain subclassification to evaluate the effects of treatment on pain, kinematics, and muscle activity during functional neck movements. The point of pain occurrence suggests increasing mechanical load on tissues may be one of the causative factors for movement-associated neck pain.

Acupuncture for chronic neck pain with sensitive points: study protocol for a multicentre randomised controlled trial

INTRODUCTION

Chronic neck pain is a challenging condition to treat in clinical practice and has a considerable impact on quality of life and disability. According to the theory of traditional Chinese medicine, acupoints and tender points may become sensitised when the body is in a diseased state. Stimulation of such sensitive points may lead to disease improvement and improved clinical efficacy. This study aims to evaluate the efficacy and safety of needling at sensitive acupoints in providing pain relief, improvement of cervical vertebral function and quality of life in patients with chronic neck pain.

METHODS AND ANALYSIS

This multicentre, randomised controlled, explanatory and parallel clinical trial will include 716 patients with chronic neck pain. Study participants will be randomly assigned in a 1:1:1:1 ratio to four treatment groups: the highly sensitive acupoints group, low/non-sensitive acupoints group, sham acupuncture group and waiting-list control group. The primary outcome will be the change in the visual analogue scale score for neck pain from baseline to 4 weeks. Secondary outcomes will be the Northwick Park Neck Pain Questionnaire and McGill pain questionnaire, 12-item Short-Form health survey, Neck Disability Index, changes in the pressure pain threshold, range of cervical motion, Self-Rating Anxiety Scale, Self-Rating Depression Scale and adverse events before treatment, post-treatment, and at 4, 8, 12, 16 and 20 weeks post-treatment. The intention-to-treat approach will be used in the statistical analysis. Group comparisons will be undertaken using χ2 tests for categorical characteristics, and analysis of variance for continuous variables to analyse whether acupuncture in the highly sensitive acupoints group achieves better treatment outcomes than in each of the other three groups.

ETHICS AND DISSEMINATION

Ethical approval of this study has been granted by the local Institutional Review Board (ID: 2017 KL-038). The outcomes of the trial will be disseminated through peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR1800016371; Pre-results.

Immediate effects of real-time postural biofeedback on spinal posture, muscle activity, and perceived pain severity in adults with neck pain

BACKGROUND

Previous studies have investigated various types of postural biofeedback devices on different body regions to improve posture; however, they focused only on healthy adults without a history of chronic musculoskeletal disorders. In addition, those postural biofeedback devices used in previous studies are often designed for experimental research. The designs are usually bulky with many wires, which is not practical for everyday use.

RESEARCH QUESTION

The aim of this study was to determine the immediate effect of a commercially available real-time postural biofeedback device on spinal posture, muscle activity, and perceived pain severity in adults with neck pain.

METHODS

21 adults who had chronic or recurrent nonspecific neck pain for more than 3 months and whose pain was induced or aggravated by prolonged computer work were enrolled in this study. Spinal posture (head tilt, neck flexion, cervical and thoracic angles), muscle activity (cervical erector spinae, upper trapezius, and thoracic erector spinae), and self-reported neck and shoulder pain were measured during computer typing tasks, with and without biofeedback.

RESULTS

Compared with the non-biofeedback condition, the biofeedback condition significantly decreased neck flexion, upper cervical, and lower thoracic angles and lowered the activity of the cervical erector spinae. Self-reported neck pain was not influenced by the application of biofeedback, but significantly increased over the 1-hour typing task.

SIGNIFICANCE

The application of a commercially available wearable real-time biofeedback device improves sitting posture and reduces muscular activity in adults with nonspecific neck pain during computer work. Future studies should examine the long-term effects of wearable real-time postural biofeedback devices for prevention and management of neck pain.

Effects of deep cervical flexor training on impaired physiological functions associated with chronic neck pain: a systematic review

Background

Neck pain is a major health issue with high rates of recurrence. It presents with a variety of altered sensorimotor functions. Exercise is a cornerstone of rehabilitation and many training methods are used. Exercise is evaluated in most randomized controlled trials on its pain relieving effects. No review has assessed the effect of exercise on the altered physiological functions or determined if there are differential effects of particular training methods. This review investigated the effects of deep cervical flexor (DCF) training, a training method commonly used for patients with neck pain, and compared it to other training methods or no training on outcomes of cervical neuromuscular function, muscle size, kinematics and kinetics.

Methods

Web of Science, Scopus, CINAHL, PubMed were searched from inception until January 2018. Twelve randomized controlled trials were included that compared DCF training as sole intervention to other training or no interventions in persons with neck pain. The Cochrane Risk of Bias tool was used to assess the method quality. All outcome measures were analysed descriptively and meta-analyses were performed for measures evaluated in three or more studies.

Results

DCF training was compared to cervical endurance, strength, proprioception and mobility training, muscle stretching, and no intervention control groups. Physiological outcome measures included neuromuscular co-ordination (craniocervical flexion test), functional tasks, muscle fatigability, muscle size, kinematics (joint position sense, posture and range of motion) and kinetics (strength, endurance and contraction accuracy). Strong evidence was found for effectiveness of DCF training on neuromuscular coordination, but it had no or small effects on strength and endurance at higher loads. DCF training improved head and cervical posture, while evidence was limited or contradictory for other measures.

Conclusions

DCF training can successfully address impaired neuromuscular coordination, but not cervical flexor strength and endurance at higher contraction intensities. A multimodal training regime is proposed when the aim is to specifically address various impaired physiological functions associated with neck pain.

A Convenient Non-harm Cervical Spondylosis Intelligent Identity method based on Machine Learning

Cervical spondylosis (CS), a most common orthopedic diseases, is mainly identified by the doctor's judgment from the clinical symptoms and cervical change provided by expensive instruments in hospital. Owing to the development of the surface electromyography (sEMG) technique and artificial intelligence, we proposed a convenient non-harm CS intelligent identify method EasiCNCSII, including the sEMG data acquisition and the CS identification. Faced with the limit testable muscles, the data acquisition method are proposed to conveniently and effectively collect data based on the tendons theory and CS etiology. Faced with high-dimension and the weak availability of the data, the 3-tier model EasiAI is developed to intelligently identify CS. The common features and new features are extracted from raw sEMG data in first tier. The EasiRF is proposed in second tier to further reduce the data dimension, improving the performance. A classification model based on gradient boosted regression tree is developed in third tier to identify CS. Compared with 4 common machine learning classification models, the EasiCNCSII achieves best performance of 91.02% in mean accuracy, 97.14% in mean sensitivity, 81.43% in mean specificity, 0.95 in mean AUC.

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.

Differences in neck surface electromyography, kinematics and pain occurrence during physiological neck movements between neck pain and asymptomatic participants. A cross-sectional study

BACKGROUND

Neck pain has been associated with altered muscle activity and impaired kinematics. Patients frequently report pain during physiological neck movements. Previously, the average muscle activity during these movements has been measured. However, muscle activity is modulated by the position in the range of movement, hence the study of neck muscle activity in discrete sections of the range of movement is warranted. Evidence is conflicting regarding range of movement restriction in neck pain. No study has assessed the point in the range of movement at which pain occurs. This study aimed to investigate neck kinematics, muscle activity and pain during physiological neck movements in participants with and without neck pain.

METHODS

Neck kinematics and surface electromyography were recorded continuously and analysed in 10° increments during forward and side flexion, extension and rotation of the neck in 20 neck pain and 20 asymptomatic participants. Point of pain occurrence in the range of movement was recorded.

FINDINGS

Neck pain participants demonstrated significantly lower activity of scalene during flexion and extension, and a non-significant higher activity in sternocleidomastoids during rotation. No differences in neck kinematics were observed. 65% of neck pain participants reported pain during at least one neck movement. Pain was reported in the last ≈20-40% of the range of movement.

INTERPRETATION

Exercises used in current practice to minimise scalene activity may not be appropriate for all neck pain patients. Restricted range of movement is not a consistent feature of neck pain. Movement associated neck pain is present at the end of range of movement, which has implications for the study of neck pain and rehabilitation.

Workplace Factors Associated With Neck Pain Experienced by Computer Users: A Systematic Review

INTRODUCTION

The purpose of this systematic review was to examine literature on workplace factors associated with neck pain or symptoms in computer users performing clerical functions.

METHODS

A systematic search of the Cochrane, Medline, CINAHL, and EMBASE databases was conducted for observational and experimental studies published since 2000. This review applied the case definition of The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders.

RESULTS

Seven hundred twenty-nine studies were identified. Seven hundred and two studies were excluded. Twenty-seven studies fulfilled inclusion criteria and were assessed for risk of bias. Cross-sectional studies were commonly at risk from nonresponse bias and lack of adequate case definitions. Experimental studies were mostly at risk of bias due to confounding and participant recruitment methods.

CONCLUSIONS

Neck pain was not significantly associated with high job demands, low skill discretion, low decision authority, or low peer support. However, when these variables were combined with increased duration of computing tasks, or ergonomic demands, they reached significance. Supervisor support was found to be the only significant buffer capable of preventing these variables reaching significance in female office workers.

The coordination of shoulder girdle muscles during repetitive arm movements at either slow or fast pace among women with or without neck-shoulder pain

PURPOSE

The aim of this study was to evaluate the coordination of the shoulder girdle muscles among subjects with or without neck-shoulder pain performing repetitive arm movement at either a slow or fast pace.

METHODS

Thirty female adults were allocated to one of two groups-healthy controls or cases with neck-shoulder pain. Surface electromyography (sEMG) signals from the clavicular, acromial, middle and lower trapezius portions and the serratus anterior muscles were recorded during a task performed for 20min at a slow pace and 20min at a fast pace. The root mean square (RMS), relative rest time (RRT) and normalised mutual information (NMI, an index of functional connectivity between two muscles in a pair) were computed.

RESULTS

No significant differences on RMS, RRT and NMI were found between groups. For both groups, the fast movement pace resulted in increased levels of RMS, lower degrees of RRT and higher NMI compared to the slow pace. No interaction between group and movement pace was found.

CONCLUSIONS

This study highlights the change in sEMG activity of muscles to meet the demands of performing a task at fast movement pace. The fast pace imposed a higher muscle demand evidenced by increased sEMG amplitude, low degree of muscle rest and increased functional connectivity for subjects in both the case and control groups. No indication of impaired sEMG activity was found in individuals with neck-shoulder pain.

The effect of psychosocial stress on muscle activity during computer work: Comparative study between desktop computer and mobile computing products

BACKGROUND

The popularity of mobile computing products is well known. Thus, it is crucial to evaluate their contribution to musculoskeletal disorders during computer usage under both comfortable and stressful environments.

OBJECTIVE

This study explores the effect of different computer products' usages with different tasks used to induce psychosocial stress on muscle activity.

METHODS

Fourteen male subjects performed computer tasks: sixteen combinations of four different computer products with four different tasks used to induce stress. Electromyography for four muscles on the forearm, shoulder and neck regions and task performances were recorded.

RESULTS

The increment of trapezius muscle activity was dependent on the task used to induce the stress where a higher level of stress made a greater increment. However, this relationship was not found in the other three muscles. Besides that, compared to desktop and laptop use, the lowest activity for all muscles was obtained during the use of a tablet or smart phone. The best net performance was obtained in a comfortable environment. However, during stressful conditions, the best performance can be obtained using the device that a user is most comfortable with or has the most experience with.

CONCLUSIONS

Different computer products and different levels of stress play a big role in muscle activity during computer work. Both of these factors must be taken into account in order to reduce the occurrence of musculoskeletal disorders or problems.

Adaptations in Evoked Pain Sensitivity and Conditioned Pain Modulation after Development of Chronic Neck Pain

Numerous studies demonstrate elevated pain sensitivity and impaired conditioned pain modulation (CPM) in patients with chronic musculoskeletal pain compared to healthy individuals; however, the time course of changes in pain sensitivity and CPM after the development of a chronic pain condition is unclear. Secondary analysis of data from a prospective investigation examined changes in evoked pain sensitivity and CPM before and after development of chronic neck pain (CNP). 171 healthy office workers participated in a baseline assessment, followed by monthly online questionnaires to identify those who developed CNP over the subsequent year. These individuals (N = 17) and a cohort of participants (N = 10) who remained pain-free during the follow-up period returned for a 12-month follow-up assessment of mechanical and thermal pain sensitivity and CPM. Pain sensitivity measures did not differ between groups at baseline; however, cold pain threshold decreased in the CNP group at follow-up (p < 0.05). CPM was lower at baseline in the CNP group compared to those who reported no neck pain (p < 0.02) and remained unchanged one year later. These findings indicate that CPM is reduced in healthy individuals prior to the development of chronic neck pain and the subsequent reduction of thresholds for cold but not pressure pain.

Associations between musculoskeletal pain and work-related factors among public service sector computer workers in Kaunas County, Lithuania

Background

Information technologies in occupational activities have been developing very rapid. Epidemiological studies have shown that musculoskeletal disorders are widely prevalent among employees working with a computer. The aim of this study was to evaluate the prevalence of musculoskeletal pain in various anatomical areas and its associations with individual, ergonomic, and psychosocial factors among computer workers of the public sector in Kaunas County, Lithuania.

Methods

The investigation consisting of two parts – questionnaire study (Nordic Musculoskeletal Questionnaire and Copenhagen Psychosocial Questionnaire) and direct observation (evaluation of work ergonomics using the Rapid Upper Limb Assessment [RULA]) – was carried out in three randomly selected public sector companies of Kaunas County. The representative study sample comprised 513 public service office workers. The prevalence of musculoskeletal pain in five anatomical areas of the body (shoulders, elbows, wrists/hands, as well as upper and low back) was evaluated.

Results

The prevalence rates of shoulder, elbow, wrist/hand, upper and low back pain were 50.5 %, 20.3 %, 26.3 %, 44.8 %, and 56.1 %, respectively. Individual factors such as gender, age, computer work experience, and body mass index were found as significant for musculoskeletal pain in various musculoskeletal regions. The respondents reporting pain in shoulder, wrist/hand, upper back, and low back areas had a statistically significantly higher mean RULA score. The duration of working with a computer was found as a significant factor for shoulder pain. High quantitative demands were related to musculoskeletal pain in all investigated anatomical areas expect for the low back; weak social support was a significant predictor for complaints in upper and low back areas.

Conclusion

This study confirmed associations between musculoskeletal pain and work ergonomics; therefore, preventive measures at the workplace should be directed to the improvement in ergonomic work environment, education, and workload optimization.

The Effects of High-Frequency Transcutaneous Electrical Nerve Stimulation for Dental Professionals with Work-Related Musculoskeletal Disorders: A Single-Blind Randomized Placebo-Controlled Trial

Work-related musculoskeletal symptom disorders (WMSDs) have a significant issue for dental professionals. This study investigated the effects of high-frequency transcutaneous electrical nerve stimulation (TENS) on work-related pain, fatigue, and the active range of motion in dental professionals. Among recruited 47 dental professionals with WMSDs, 24 subjects received high-frequency TENS (the TENS group), while 23 subjects received placebo stimulation (the placebo group). TENS was applied to the muscle trigger points of the levator scapulae and upper trapezius, while placebo-TENS was administered without electrical stimulation during 60 min. Pain and fatigue at rest and during movement were assessed using the visual analog scale (VAS), pain pressure threshold (PPT), and active range of motion (AROM) of horizontal head rotation at six time points: prelabor, postlabor, post-TENS, and at 1 h, 3 h, and 1 day after TENS application. Both groups showed significantly increased pain and fatigue and decreased PPT and AROM after completing a work task. The TENS group showed significantly greater improvements in VAS score, fatigue, PPT, and AROM at post-TENS and at 1 h and 3 h after application (all P < 0.05) as compared to the placebo group. A single session high-frequency TENS may immediately reduce symptoms related to WMSDs in dental professionals.

Immediate and Short-Term Effects of Upper Thoracic Manipulation on Myoelectric Activity of Sternocleidomastoid Muscles in Young Women With Chronic Neck Pain: A Randomized Blind Clinical Trial

OBJECTIVE

The aim of this study was to assess the immediate and short-term effects of upper thoracic spine manipulation on pain intensity and myoelectric activity of the sternocleidomastoid muscles in young women with chronic neck pain.

METHODS

A randomized clinical trial was carried out involving 32 women with chronic neck pain (mean age, 24.8 ± 5.4 years) allocated to an experimental group and a placebo group. Three evaluations were carried out: baseline, immediate postintervention, and short-term postintervention (48-72 hours after intervention). Myoelectric activity of the right and left sternocleidomastoid muscles was assessed at rest and during isometric contractions for cervical flexion and elevation of the shoulder girdle. Neck pain intensity was assessed at rest using a visual analog scale. Comparisons of the data were performed using 2-way repeated-measures analysis of variance with the Bonferroni correction. The level of significance was set at P < .05.

RESULTS

A moderate treatment effect on myoelectric activity of the right and left sternocleidomastoid muscles during isometric elevation of the shoulder girdle was found in the experimental group only on the short-term postintervention evaluation (d > 0.40). No statistically significant differences were found for any of the variables analyzed in the intergroup comparisons at the different evaluation times (P > .05).

CONCLUSION

No statistically significant differences were found in the intragroup or intergroup analyses of the experimental and placebo groups regarding myoelectric activity of the cervical muscles or the intensity of neck pain at rest in the immediate or short-term postintervention evaluations.

Neck muscle function in violinists/violists with and without neck pain

Neck pain is associated with changes in neuromuscular control of cervical muscles. Violin and viola playing requires good function of the flexor muscles to stabilize the instrument. This study investigated the flexor muscle behaviour in violin/viola players with and without neck pain using the craniocervical flexion test (CCFT). In total, 12 violin/viola players with neck pain, 21 violin/viola players without neck pain in the preceding 12 weeks and 21 pain-free non-musicians were included. Activity of the sternocleidomastoid muscles (SCM) was measured with surface electromyography (EMG) during the CCFT. Violin/viola players with neck pain displayed greater normalised SCM EMG amplitudes during CCFT than the pain-free musicians and non-musicians (P < 0.05). Playing-related neck pain in violinists/violists is associated with altered behaviour of the superficial neck flexor muscles consistent with neck pain, despite the specific use of the deep and superficial neck flexors during violin playing.

Analysis of scapular muscle EMG activity in patients with idiopathic neck pain: a systematic review

It is proposed that altered scapular muscle function can contribute to abnormal loading of the cervical spine. However, it is not clear if patients with idiopathic neck pain show altered activity of the scapular muscles. The aim of this paper was to systematically review the literature regarding the differences or similarities in scapular muscle activity, measured by electromyography ( = EMG), between patients with chronic idiopathic neck pain compared to pain-free controls. Case-control (neck pain/healthy) studies investigating scapular muscle EMG activity (amplitude, timing and fatigue parameters) were searched in Pubmed and Web of Science. 25 articles were included in the systematic review. During rest and activities below shoulder height, no clear differences in mean Upper Trapezius ( = UT) EMG activity exist between patients with idiopathic neck pain and a healthy control group. During overhead activities, no conclusion for scapular EMG amplitude can be drawn as a large variation of results were reported. Adaptation strategies during overhead tasks are not the same between studies. Only one study investigated timing of the scapular muscles and found a delayed onset and shorter duration of the SA during elevation in patients with idiopathic neck pain. For scapular muscle fatigue, no definite conclusions can be made as a wide variation and conflicting results are reported. Further high quality EMG research on scapular muscles (broader than the UT) is necessary to understand/draw conclusions on how scapular muscles react in the presence of idiopathic 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.

Neck and shoulder muscle activity during standardized work-related postural tasks

The aim of the present study was to assess the activity levels of the sternocleidomastoid muscle and upper trapezius muscle during static postures under controlled and standardized conditions, and to determine whether the muscle activity differed between sexes. Electromyographic (EMG) activity was recorded unilaterally from the sternocleidomastoid and upper trapezius muscle in 17 participants whilst they were performing various postural tasks. EMG amplitude was measured by the root mean square values of the raw signals and normalized to peak maximum contractile values for each muscle (%MVC). The intensity of muscle activity was ranked as light (<3%MVC), moderate (3%MVC ≤ EMG ≤ 8%MVC), and substantial (>8%MVC). During most tasks the two muscles contracted light to moderately. Head leaning and shoulder shrugging postures yielded substantial muscle activity in both muscles. Muscle activity did not differ significantly between male and female participants (F = 3.1; p = 0.078). Our findings provided normative values, which will enhance future studies of muscle activity during work in a natural, unrestrained environment.

Evaluation of document location during computer use in terms of neck muscle activity and neck movement

This study evaluated the impact on neck movement and muscle activity of placing documents in three commonly used locations: in-line, flat desktop left of the keyboard and laterally placed level with the computer screen. Neck excursion during three standard head movements between the computer monitor and each document location and neck extensor and upper trapezius muscle activity during a 5 min typing task for each of the document locations was measured in 20 healthy participants. Results indicated that muscle activity and neck flexion were least when documents were placed laterally suggesting it may be the optimal location. The desktop option produced both the greatest neck movement and muscle activity in all muscle groups. The in-line document location required significantly more neck flexion but less lateral flexion and rotation than the laterally placed document. Evaluation of other holders is needed to guide decision making for this commonly used office equipment.

Altered Co-contraction of Cervical Muscles in Young Adults with Chronic Neck Pain during Voluntary Neck Motions

[Purpose] Muscle co-contraction is important in stabilizing the spine. The aim of this study was to compare cervical muscle co-contraction in adults with and without chronic neck pain during voluntary movements. [Subjects and Methods] Surface electromyography of three paired cervical muscles was measured in fifteen young healthy subjects and fifteen patients with chronic neck pain. The subjects performed voluntary neck movements in the sagittal and coronal plane at slow speed. The co-contraction ratio was defined as the normalized integration of the antagonistic electromyography activities divided by that of the total muscle activities. [Results] The results showed that the co-contraction ratio of patients was greater during flexion movement, lesser during extension movement, slightly greater during right lateral bending, and slightly lesser during left lateral bending compared with in the controls. [Conclusion] The results suggested that neck pain patients exhibit greater antagonistic muscle activity during flexion and dominate-side bending movements to augment spinal stability, while neuromuscular control provides relatively less protection in the opposite movements. This study helps to specify the changes of the stiffness of the cervical spine in neck pain patients and provides a useful tool and references for clinical assessment of neck disorders.

Comparison of risk assessment procedures used in OCRA and ULRA methods

The aim of this study was to analyse the convergence of two methods by comparing exposure and the assessed risk of developing musculoskeletal disorders at 18 repetitive task workstations. The already established occupational repetitive actions (OCRA) and the recently developed upper limb risk assessment (ULRA) produce correlated results (R = 0.84, p = 0.0001). A discussion of the factors that influence the values of the OCRA index and ULRA's repetitive task indicator shows that both similarities and differences in the results produced by the two methods can arise from the concepts that underlie them. The assessment procedure and mathematical calculations that the basic parameters are subjected to are crucial to the results of risk assessment. The way the basic parameters are defined influences the assessment of exposure and risk assessment to a lesser degree. The analysis also proved that not always do great differences in load indicator values result in differences in risk zones.

PRACTITIONER SUMMARY

We focused on comparing methods that, even though based on different concepts, serve the same purpose. The results proved that different methods with different assumptions can produce similar assessment of upper limb load; sharp criteria in risk assessment are not the best solution.

Rehabilitation of scapular dyskinesis: from the office worker to the elite overhead athlete

The scapula functions as a bridge between the shoulder complex and the cervical spine and plays a very important role in providing both mobility and stability of the neck/shoulder region. The association between abnormal scapular positions and motions and glenohumeral joint pathology has been well established in the literature, whereas studies investigating the relationship between neck pain and scapular dysfunction have only recently begun to emerge. Although several authors have emphasised the relevance of restoring normal scapular kinematics through exercise and manual therapy techniques, overall scapular rehabilitation guidelines decent for both patients with shoulder pain as well as patients with neck problems are lacking. The purpose of this paper is to provide a science-based clinical reasoning algorithm with practical guidelines for the rehabilitation of scapular dyskinesis in patients with chronic complaints in the upper quadrant.

Effectiveness of an 8-week exercise programme on pain and specificity of neck muscle activity in patients with chronic neck pain: a randomized controlled study

BACKGROUND

Although exercise can be effective for relief of neck pain, little is known about the effect of exercise on the neural control of neck muscles.

METHODS

A randomized controlled trial was conducted on 46 women with chronic neck pain to investigate the immediate effectiveness of an 8-week exercise programme on pain and directional specificity of neck muscle activity. At baseline, the patients completed questionnaires including the neck disability index (NDI) and performed a circular contraction of their head in the horizontal plane at 15 N force, with continuous change in force direction in the range 0-360°. Electromyography (EMG) was recorded from the sternocleidomastoid (SCM) and splenius capitis (SCap) muscles. Tuning curves of the EMG amplitude were computed, which depicts muscle activity over a range of force directions. The mean point of the tuning curves defined a directional vector, which determined the specificity of muscle activity. Patients were randomly assigned either to a training or control group.

RESULTS

A significant between-group difference in the change in NDI was observed. A reduction in NDI was observed following training (pre: 18.2 ± 7.4; post: 14.1 ± 6.5; p < 0.01) but not for the control group (pre: 17.5 ± 6.3; post: 16.6 ± 7.4). The training group showed higher specificity of muscle activity post-intervention (pre: 18.6 ± 9.8%, post: 24.7 ± 14.3%; p < 0.05), whereas no change occurred for the control group (pre: 19.4 ± 11.9%, post: 18.2 ± 10.1%).

CONCLUSION

An exercise programme that aims to enhance motor control of the cervical spine improves the specificity of neck muscle activity and reduces pain and disability in patients with neck pain.

The effects of workplace stressors on muscle activity in the neck-shoulder and forearm muscles during computer work: a systematic review and meta-analysis

Workplace stressors have been indicated to play a role in the development of neck and upper extremity pain possibly through an increase of sustained (low-level) muscle activity. The aim of this review was to study the effects of workplace stressors on muscle activity in the neck-shoulder and forearm muscles. An additional aim was to find out whether the muscles of the neck-shoulder and the forearm are affected differently by different types of workplace stressors. A systematic literature search was conducted on studies investigating the relation between simulated or realistic workplace stressors and neck-shoulder and forearm muscle activity. For studies meeting the inclusion criteria, a risk of bias assessment was performed and data were extracted for synthesis. Results were pooled when possible and otherwise described. Twenty-eight articles met the inclusion criteria, reporting data of 25 different studies. Except for one field study, all included studies were laboratory studies. Data of 19 articles could be included in the meta-analysis and revealed a statistically significant, medium increase in neck-shoulder and forearm muscle activity as a result of workplace stressors. In subgroup analyses, we found an equal effect of different stressor types (i.e. cognitive/emotional stress, work pace, and precision) on muscle activity in both body regions. In conclusion, simulated workplace stressors result in an increase in neck-shoulder and forearm muscle activity. No indications were found that different types of stressors affect these body regions differently. These conclusions are fully based on laboratory studies, since field studies on this topic are currently lacking.

Construct validity and test-retest reliability of the Fatigue Severity Scale in people with chronic neck pain

OBJECTIVE

To investigate an appropriate scoring system and unidimensionality using Rasch analysis, discriminant validity, and reliability of the Fatigue Severity Scale (FSS) in people with chronic neck pain.

DESIGN

Cross-sectional.

SETTING

Tertiary institution.

PARTICIPANTS

Patients with chronic neck pain (n=100) and asymptomatic controls (n=40).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The FSS.

RESULTS

Twenty-six of the 100 participants with chronic neck pain agreed to complete the FSS again within 1 week after the first administration for the assessment of the test-retest reliability. Two items obviously threatening unidimensionality were eliminated, and the 7-item FSS was developed through Rasch analyses. The 7-item FSS demonstrated the appropriateness of its 7-point scale and adequate internal consistency (Rasch-generated reliability, .83-.91). The 7-item FSS had a negligible floor effect (1%) and ceiling effect (2%). The item-person map demonstrated limited distribution of item difficulty in comparison with the distribution of person ability. The chronic neck pain group demonstrated significantly (P<.001) higher scores in the 7-item FSS than the control group, indicating discriminant validity. The 7-item FSS also demonstrated adequate test-retest reliability with a mean interval of 4.1 days (n=26) for each item (quadratic-weighted κ=.83-.94), and as a whole (intraclass correlation coefficient=.95). A 0-to-100 scale table reflecting Rasch scores was developed, and the minimum detectable change was 9.5 in the 0 to 100 scale.

CONCLUSION

The 7-item FSS appears unidimensional and reliable, and can be used quickly in clinical practice to gain a basic understanding of fatigue symptoms in people with chronic neck pain. Further, it is possible to modify the 7-item FSS to enhance discriminant ability within people with chronic neck pain by adding additional items, enlarging the distribution of item difficulty.

IFOMPT 2012: a rendez-vous of hands and minds

Since its founding in Montreal, Canada in 1974, the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT) has been providing orthopaedic and manual therapists from around the world with the highest-quality learning opportunities through a conference held every 4 years. In 2012, IFOMPT is partnering with The International Private Practitioners Association (IPPA) to host this prestigious event in Quebec City, Canada. As more than 51% of the Canadian Physiotherapy Association membership is working in private practice, this adds even greater value to this quadrennial event. This conference emulates best-evidence practice in the marriage of research and clinical excellence by pulling together some of the best and brightest hands and minds in orthopaedic physiotherapy. Through a call for proposals that equally emphasized research, clinical excellence, and the knowledge translation link between the two, the IFOMPT mandate of clinical and academic excellence has been kept at the forefront of this year's conference. Included in this supplement are the IFOMPT 2012 keynote addresses, schedule, and abstracts.

A comparative investigation of flexion relaxation phenomenon in healthy and chronic neck pain subjects

PURPOSE

The cervical flexion relaxation phenomenon (FRP) is a neck extensor myoelectric "silence" that occurs during complete cervical and lumbar flexion. In contrast to low back pain, the changes that occur during FRP in chronic neck pain (CNP) patients are still not clear. The aim of this study was to assess the characteristics of this phenomenon in the cervical region in CNP patients and controls.

METHODS

Twenty-two women (23 ± 2.62 years) with chronic non-specific neck pain and 21 healthy women (23.4 ± 1.68 years) participated in this study. They accomplished a cervical flexion and extension from neutral position. Neck angle and surface electromyographic activity of cervical erector spinae (CES) and upper trapezius muscles were recorded. Appearance, onset and offset angle of the FRP were analysed and compared between the two groups.

RESULTS

There were significant differences in the appearance of FRP between the two groups (P ≤ 0.001). The FRP in the CES muscles was observed in 85.7 % of healthy subjects and in 36.3 % of CNP patients, and no FRP was observed in the upper trapezius. Results of this study show that the onset and offset of FRP parameters were significantly different between the two groups (P ≤ 0.001).

CONCLUSIONS

The results of the present study indicate that FRP in CNP patients was seen less than the healthy subjects, and moreover the FRP period was reduced in CNP patients. Our results also suggest that the changes in FRP of CNP patients may be due to the increased CES activity in these patients.