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Objective This study aimed to determine the correlation between gadget usage and the tension of cervical muscles in the gamers community. Methods This study is an analytical study using a cross-sectional approach. This research was conducted at the Game Play Unknown Battleground (PUBG) Community in Makassar. Forty people (n = 40) were included in the present study. Data including age, gender, and intensity (duration) of gadget usage, were collected using a questionnaire. Cervical muscle tension was assessed by palpation test and using goniometer. Results The relationship between the intensity of gadget usage in-game players and cervical muscle tension were found statistically significant (p Conclusion The intensity of gadget usage and age have a positive correlation with the development of cervical muscle tension in-game players.

A reduced capacity to generate and sustain cervical muscle force over a range of contraction intensities is a feature of some participants with neck pain. To date there have been no studies comparing the accuracy of force perception in participants with and without neck pain.Cross-sectional observational study.Participants with (n = 25) and without (n = 25) neck pain performed isometric muscle contractions at three progressive self-perceived (no feedback provided) intensities (10, 25, 50) % of their maximal voluntary contraction (MVC) in cervical: flexion, extension, right and left lateral flexion. Absolute error (AE), constant error (CE), and variable error (VE) between actual and targeted force values were calculated.The neck pain group had: (1) AE-combined direction -significantly higher at 10% and lower at 50% (p 0.05); (2) significantly lower CE in most measures (p 0.05); (3) higher mean VE in all measures, with 10, 25, and 50% combined direction and overall combined % extension significantly higher (p 0.05).Findings indicate higher variability in force generation perception across all directions and intensities in participants with neck pain compared to healthy controls. Potentially this greater variability might suggest impaired force sense, a construct of proprioception in participants with neck pain. Reduced force sense may have implications for participants with neck pain during functional activities requiring precision and may need to be trained. Further research is required.

Background Concussions have become a significant public health concern with rising incidence rates. Concussions have been shown to occur concurrently with neck injuries, such as whiplash-associated-disorder, therefore, understanding the role of the neck in concussions is important. Objectives To determine if there is a relationship between cervical muscle endurance and either concussion incidence, or concussion recovery in university athletes. Specifically, the primary aim was to investigate a relationship between pre-season deep neck flexor endurance test (DNFET) time in those who sustained an in-season injury versus those who did not. The secondary aim is to determine correlation in DNFET times and concussion recovery. Design Longitudinal observational study. Methods Pre-season DNFET was performed on university athletes. In the event of a concussion, cervical endurance and neuromuscular adaptation was re-assessed with the DNFET. Rehabilitative exercises were prescribed, as required, and DNFET was measured at subsequent treatments. Results There was no significant difference between pre-season DNFET times and concussion incidence (p = 0.55). However, there was a moderate correlation between DNFET times and concussion recovery (R = 0.47, p = 0.001) whereby DNFET times improved predictively throughout rehabilitation. Conclusions While no statistically significant relationship was found between DNFET and concussion incidence, a significant clinical relationship was present with recovery. The validity of the DNFET test as a means for assessing risk or measuring recovery requires additional research.

Objectives The objective of this study is to explore the effect of concussion history on head control during front on rugby tackles in non-professional male and female Rugby Union players. Design An observational cross-sectional design. Setting A laboratory-based study of simulated front on rugby tackles with a dynamic relatively-weighted (∼50% body-mass) tackle bag. Participants 27 club Rugby Union players were recruited; 10 (7female) with no-concussion history, 10 (3female) within 12-months of concussion and 7 (3female) with 24 + months since last concussion. Main outcome measures Linear and rotational head acceleration measured with a skin mounted CSx® triaxial accelerometer. Normalized Surface EMG amplitude of the bilateral sternocleidomastoid (Scm), upper trapezius (Trap) and splenius capitis (Spl). All outcome measures were synchronised with moment of impact with the tackle bag. Results A mixed-model analysis showed that players with 12-Month concussion history had the highest head acceleration (females = 48.6g, males = 68.3g, p Conclusions These findings suggest probable disruption to neuromuscular control of the head in athletes with concussion history as a potential mechanism for recurrent concussion incidence.

Objectives The aim of the study was to verify associations among degenerative changes in the cervical spine, head and neck postures, and myofascial pain in the craniocervical musculature in elderly with myofascial temporomandibular disorders (TMDs). Methods A total of 120 participants (mean age, 68.3 ± 7.5 years) were included: 45 participants had no signs of orofacial or cervical pain, 26 participants had myofascial TMD only (mTMD), and 49 participants had both myofascial TMD and cervical pain (cerTMD). Participants were diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders. Cervical spine degeneration and head and neck postures were identified using the lateral cephalogram. Myofascial trigger points (TrPs) were evaluated in the temporalis, masseter, trapezius, sternocleidomastoid, sub-occipitalis, and splenius capitis muscles. Relationships among number of TrPs, head postures, and cervical degeneration were investigated using repeated-measure analysis of variance and Pearson’s correlation coefficient. Results The cerTMD showed higher number of active TrPs in the masticatory and cervical muscles, greater forward head posture, and more severe degenerative changes in the cervical spine than mTMD did. The degenerative changes in each level of the cervical spine had complex interactions with head postures. Cervical degeneration, particularly at level of second to third vertebra appeared to be linked to the development of active TrPs in the masticatory and cervical muscles. Conclusions The results of this study demonstrated that degenerative changes in the cervical spine were related to altered head postures and the development of active TrPs in the craniocervical musculature in elderly with myofascial TMD.

Objective To compare comprehensive measures of scalp-recorded muscle activity in migraineurs and controls. Method We used whole-of-head high-density scalp electrical recordings, independent component analysis (ICA) and spectral slope of the derived components, to define muscle (electromyogram-containing) components. After projecting muscle components back to scalp, we quantified scalp spectral power in the frequency range, 52–98 Hz, reflecting muscle activation. We compared healthy subjects (n = 65) and migraineurs during a non-headache period (n = 26). We also examined effects due to migraine severity, gender, scalp-region and task (eyes-closed and eyes-open). We could not examine the effect of pre-ictal versus inter-ictal versus post-ictal as this information was not available in the pre-existing dataset. Results There was more power due to muscle activity (mean ± SEM) in migraineurs than controls (respectively, −13.61 ± 0.44 dB versus −14.73 ± 0.24 dB, p = 0.028). Linear regression showed no relationship between headache frequency and muscle activity in any combination of region and task. There was more power during eyes-open than eyes-closed (respectively, −13.42 ± 0.34 dB versus −14.92 ± 0.34 dB, p = 0.002). Conclusions There is an increase in cranial and upper cervical muscle activity in non-ictal migraineurs versus controls. This raises questions of the role of muscle in migraine, and the possible differentiation of non-ictal phases. Significance This provides preliminary evidence to date of possible cranial muscle involvement in migraine.

Deep cervical muscles play an important role in creating neck stability. Several changes in muscles function have been observed in people with neck pain. With regard to the problems of recording activity of cervical multifidus muscle with EMG, ultrasound has been used to evaluate the activity of this muscle. Purpose of this paper is investigation the effect of shoulder joint activities on the cervical multifidus muscle thickness changes in people with and without neck pain and providing predictive models by response surface methodology for the relationship between this factors. So, after data clustering in two groups of over 50% and less than 50% of maximum voluntary contraction (MVC), predictive models for each subjects, two groups, both left and right sides and six activities calculated. R2 (regression correlation coefficient) values of the resulting models in healthy subjects and people with neck pain are between 0.24–0.96 and 0.09–0.87, respectively. By assessing the resulting models, it seems that assessment the thickness of this muscle in the dominant hand side during shoulder abduction activity in the strength of 0–50% MVC for healthy subjects and 50–100% MVC for people with neck pain can be an appropriate factor for evaluation the behavior of this muscle.

Morphometric changes to cervical musculature in whiplash associated disorder have been reported in several studies with varying results. However, the evidence is not clear because only a limited number of cohorts have been studied and one cohort has been reported in multiple publications. The aim of this study was to assess the evidence for cervical muscle morphometric changes on magnetic resonance (MR) images after whiplash using a systematic review with meta-analysis.PubMed, MEDLINE and Cochrane Library were searched without language restriction using combinations of the MeSH terms "muscles", "whiplash injuries", and "magnetic resonance imaging". Studies of acute and chronic whiplash were included if they compared whiplash and control cervical spine muscle morphometry measurements from MR images. The search identified 380 studies. After screening, eight studies describing five cohorts (one acute, three chronic, one both acute and chronic) met the inclusion criteria. Participant characteristics and outcome measures were extracted using a standard extraction format. Quality of eligible studies was assessed using the Newcastle-Ottawa Scale. Muscle cross-sectional area (CSA) and fat infiltrate (MFI) for acute and chronic whiplash cohorts were compared using mean difference and 95% confidence intervals. Meta-analysis models were created when data from more than two eligible cohorts was available, using inverse-variance random-effects models (RevMan5 version 5.3.5).Quality assessment was uniformly good but only two studies blinded the assessor. Analysis of the acute cohorts revealed no consensus with respect to CSA. MFI was not measured in the acute cohorts. Analysis of the chronic cohorts revealed CSA is probably increased in some muscles after whiplash but there is insufficient evidence to confirm whether MFI is also increased. Because the available data were limited, meta-analyses of only multifidus were performed. In chronic whiplash multifidus CSA was significantly increased at C5 (Z = 3.51, p 0.01) and C6 (Z = 2.66, p 0.01); and MFI was significantly increased at C7 only (Z = 2.52, p 0.01) but the heterogeneity was unacceptably high (IThe strength of the evidence for cervical muscle morphometric changes on MR images after whiplash is inconsistent for CSA and MFI. Future study designs should be standardised with quantification of three-dimensional muscle morphometry.

OBJECTIVE Unruptured intracranial vertebral artery dissection (VAD) generally heals spontaneously. A chronological evaluation of intramural hematoma (IMH) using T1-weighted vessel wall imaging (VWI) may provide a more detailed understanding of the pathophysiology of VAD. We herein investigated the relationship between chronological signal changes in IMH on VWI and the spontaneous healing of VAD. MATERIALS AND METHODS We retrospectively investigated 26 patients with 27 unruptured VADs who underwent magnetic resonance (MR) imaging more than three times during the follow-up period. Morphological changes were evaluated using MR angiography (MRA). The relative signal intensity (RSI) of IMH against the posterior cervical muscle on T1-weighted VWI was calculated. The ratio of chronological RSI changes was defined as follows: maximum RSI/minimum RSI (RSI max/min). Based on the median value of RSI max/min, 27 VADs were divided into VADs with and without chronological RSI changes. Statistical analyses were performed to compare clinical and radiological findings between the two groups. RESULTS Spontaneous healing occurred in 17 out of 27 VADs (63%). The median value of RSI max/min was 1.48. The RSI of VADs with chronological RSI changes (RSI max/min ≥ 1.48) increased until three weeks after their onset and decreased over time, while that of VADs without chronological RSI changes (RSI max/min

Post-cervical (pC) artificial insemination (AI) has been successfully developed for application in multiparous sows, although it has proved problematic in gilts. This study analyzes the use of pC-AI in gilts by two experiments. In the first experiment, the efficiency of pC-AI in gilts was evaluated using a multi-ring multiparous catheter (MpC), which led to 23.1% of the gilts being successfully inseminated. In gilts where insemination was not possible using an MpC, two alternatives were applied before a second attempt at insemination: 1) Vetrabutin Chlorhydrate (VC) was intramuscularly injected in order to relax the cervix; or 2) Warm extender (WE) was deposited in the cervix to modify the cervical muscle dynamics. After the application of these treatments, the success rates achieved with the MpC were 34.2% and 23.8% for VC and WE, respectively. No statistically significant differences were found in the reproductive parameters measured [farrowing (%), litter size and fecundity index] between the use of MpC, or the MpC combined with VC or WE, compared with gilts inseminated by cervical AI (control group). In the second experiment, new catheters based on the anatomical characteristics of gilts (GpC) were used, and the rate of successful pC-AI application were compared (experiment 2a): a) MpC: control; b) GpC1: multi-ring catheter of O 16 mm and inner cannula of O 3.5 mm; c) GpC2: a multi-ring catheter of O with an inner cannula of O 2.5 mm. The highest rate of successful cannula penetration was reached in the GpC2 group (60.3%) followed by GpC1 (37.0%) and MpC (19.6%) (p < 0.05). There were no differences in the above mentioned reproductive parameters using the three catheters compared with cervical AI method (control group). Moreover, prior cervical AI did not improve subsequent pC-AI application 24 h later (experiment 2b). In conclusion, Vetrabutin Chlorhydrate, warm extender or the new catheters can be considered as useful tools for improving the success rate of pC-AI technique in gilts.

Objective To evaluate the effects of three different foci of attention (internal, external and mixed) on motor learning using craniocervical flexion test in inexperienced participants. Methods Ninety healthy young adults, with no experience in the task, practiced the craniocervical flexion test under three different focus of attention: a) Mixed Focus (internal plus external), b) Internal Focus, and c) External Focus. We assessed immediate, post-training, and retention (one week after the last training session) aspects of motor learning by quantifying (i) the activity of the superficial cervical flexors muscles, (ii) craniocervical range of motion, and (iii) the performance on the craniocervical flexion test. Results None of the groups showed any significant immediate, post-training, or retention effects on superficial neck flexors activity and craniocervical range of motion progression. At immediate assessment, mixed focus had greater craniocervical flexion performance than external (MD 0.9, 95%CI 0.2 to 1.5), and internal foci (MD 1.4, 95%CI 0.8 to 2.1). At post-training, mixed focus led to better craniocervical performance compared to external (MD 1.6, 95%CI 0.8 to 2.4) and internal foci (MD 2.7, 95%CI 1.9 to 3.5). External focus had better scores on the craniocervical flexion test performance than internal focus (MD 1.1, 95%CI 0.3 to 1.9). Results remained similar at retention, with mixed focus being superior to internal (MD 2.3, 95%CI 1.7 to 3) and external foci (MD 1.5, 95%CI 0.9 to 2.1) on craniocervical flexion test performance. Similarly, the performance on the craniocervical flexion test performance remained similar at retention between external and internal foci (MD 0.9, 95%CI 0.2 to 1.5). Conclusion In inexperienced asymptomatic participants, different foci of attention were not able to change cervical muscle activity and craniocervical range of motion during the craniocervical flexion test. Mixed focus was better than external and internal focus on the craniocervical flexion test. These findings were retained after one week.

Background Neck muscle compositional changes may represent potential biomarkers contributing towards chronic neck-related pain and disability. Objectives To determine differences in muscle volume in the cervical muscles of individuals with chronic idiopathic neck pain compared with age- and sex-matched asymptomatic individuals, and to determine if these muscle variables relate to spinal level, side (left or right), age, sex, body mass index (BMI) or muscle strength. Study design Cross-sectional magnetic resonance imaging (MRI) study. Methods Muscle volume of five muscle (groups) from cervical levels C3-T1 in 20 pain and 17 asymptomatic participants were quantified using MRI: levator scapulae, multifidus including semispinalis cervicis, semispinalis, splenius capitus including splenius cervicis, and sternocleidomastoid. Isometric extensor and flexor muscle strength were assessed with a dynamometer. Linear mixed modelling determined differences between groups in muscle volume accounting for participant characteristics. Results Individuals with pain had greater muscle volume (adjusted mean difference 71.2 mm3 (95% CI 14.2–128.2, p = .015) of the sternocleidomastoid, accounting for spinal level, side, muscle group (extensors vs flexor), sex, age, body mass index and strength. Modelling indicated muscle volume differed between spinal levels (p Conclusion Between-group differences in cervical flexor muscle volume, and volume differences across spinal levels and muscles suggest the contribution of cervical muscles to chronic idiopathic neck pain is multifaceted and complex.

The present study compared the effects of using one versus two display screens on cervical muscle activity of computer users. Healthy pain-free university students were recruited (11 males and 11 females), and surface electromyography in bilateral cervical erector spinae and upper trapezius (UT) muscles was measured. Each subject performed standardized text editing tasks for 15 min using a single screen and dual screens in a randomized order. In the dual screen condition, the primary screen was placed directly in front while the secondary screen was angled to the right of the user. Significant reductions of the 50th and 90th percentile amplitudes, representative of dynamic muscle loading, were found in the right UT muscle for dual screen condition. The 10th percentile muscle activity was similar in all muscles in the two conditions. These results suggest that viewing dual screens may be associated with different postural muscle activity compared to single screen. Relevance to industry Use of two display screens is now a very common practice in the office setting. The results of this study will provide information about how the viewing of two screens will affect the muscle activity in the neck region.

Objective The aim of this study was to evaluate the maximal bite force (MBF), electromyographic (EMG) activity and thickness of the masseter, anterior part of the temporalis and sternocleidomastoid (SCM) muscles in a group of young adults with and without temporomandibular disorders (TMDs). Design Nineteen individuals comprised the TMD group (6 males/13 females, aged 25.4 ± 3.8 years), classified based on the Research Diagnostic Criteria for TMD (RDC/TMD), and 19 comprised the control group (6 males/13 females, aged 24.1 ± 3.6 years). The MBF was determined with a transducer placed between the dental arches at the first molars level (N). The muscles were evaluated bilaterally at rest and during maximal voluntary clenching (MVC) by assessing EMG activity and performing ultrasonography (USG). The mean values of these measures for both sides of the mouth were used. The normality of the distributions was assessed by the Shapiro–Wilks test. Variables between groups and genders were compared using two-way factorial ANOVA test and correlated using the Spearman coefficient (α = 0.05). Unpaired t test was used to compare variables between TMD subgroups. Logistic regression analysis was used to identify the variables associated with the presence of TMD. Results MBF, EMG and USG data were similar among clinical groups and among TMD subgroups. The thickness of masseter and SCM muscles in the relaxed and clenching states were significantly higher in males than females. On the other hand, the EMG of the temporalis muscle in the rest state was significantly higher in females than males. Additionally, the MBF was positively correlated with the USG characteristics of masseter and SCM muscles, as well as with the EMG activity of masseter and temporalis muscles in the TMD group. In this group, there was also a positive correlation between the thickness of the masseter muscle and its activity. On the other hand, the thickness of the SCM muscle was negatively correlated with its activity. A lower MBF was independently associated with the presence of TMD. Conclusions Subjects with TMD exhibited similar values of MBF, thickness and electrical activity of masticatory and cervical muscles when compared with controls; positive correlations observed between these variables may suggest a muscular alteration in TMD patients and a co-activation of masticatory and cervical muscles during mandibular movement. This fact may also be confirmed by the negative association between bite forces and presence of TMD.

Background Vestibular evoked myogenic potentials (VEMPs) have become an important part of the neuro-otological test battery. They are recorded from averaged electromyography in response to intense auditory stimuli and are used for the assessment of the otolith function. VEMPs have been recorded from tonically contracted cervical muscles and this approach is called ‘‘cervical” VEMPs (cVEMPs). They can also be recorded from extra-ocular muscles in response to loud sound and are termed ‘‘ocular” VEMPs (oVEMPs). The combined VEMPs procedure can be substituted for individual oVEMPs and cVEMPs tests. Objectives Comparing the results of combined (cVEMPs and oVEMPs) to individual cVEMPs and oVEMPs in healthy subjects. Method Individual cVEMPs and oVEMPs then combined (cVEMPs and oVEMPs) are measured and compared with each other in 50 normal healthy adults. Results cVEMPs have a detectability of 100% in both individual and combined modes with comparable latency and amplitude. While the detectability of oVEMPs was 94% in both modes of recordings, with no significant difference as regard latencies or amplitudes. Conclusion Both oVEMPs and cVEMPs tests can be recorded simultaneously with high degree of accuracy and without affecting results of each other. Combined VEMPs recording is a convenient screening tool for assessing crossed vestibule-ocular reflex and ipsilateral sacculo-collic reflex with shortened diagnostic test time and suitable for testing children and geriatric population.

Statistical significance has been used extensively to evaluate the results of research studies. Nevertheless, it offers only limited information to clinicians. The assessment of clinical relevance can facilitate the interpretation of the research results into clinical practice. The objective of this study was to explore different methods to evaluate the clinical relevance of the results using a cross-sectional study as an example comparing different neck outcomes between subjects with temporomandibular disorders and healthy controls. Subjects were compared for head and cervical posture, maximal cervical muscle strength, endurance of the cervical flexor and extensor muscles, and electromyographic activity of the cervical flexor muscles during the CranioCervical Flexion Test (CCFT). The evaluation of clinical relevance of the results was performed based on the effect size (ES), minimal important difference (MID), and clinical judgement. The results of this study show that it is possible to have statistical significance without having clinical relevance, to have both statistical significance and clinical relevance, to have clinical relevance without having statistical significance, or to have neither statistical significance nor clinical relevance. The evaluation of clinical relevance in clinical research is crucial to simplify the transfer of knowledge from research into practice. Clinical researchers should present the clinical relevance of their results.

Background The vestibular evoked myogenic potential recorded from cervical muscles (cVEMP), proved to be a useful tool in assessment of the availability of the saccular function. Recently, the emergence of VEMP recording from the extra-ocular muscles (oVEMP) promises to test both saccular and utricular function when they are evoked by air conduction and bone conduction stimuli, respectively. Objectives The current work was designed to assess the feasibility of recording oVEMP versus cVEMP in Meniere’s patients; moreover, to relate such recordings to the stage of the disease. Methods Twenty-eight middle-aged subjects of both genders with unilateral definite Meniere’s disease were involved as a study group. A control group of 20 normal middle-aged subjects was examined too. The oVEMP via air conduction and bone conduction stimulation and cVEMP via air conduction were recorded for both groups. Results All types of VEMP recording were highly reproducible among control subjects. However, they were mostly impaired or even absent in subjects with Meniere’s disease. The latency difference whether between control group and the whole study group ears or between control group ears and affected ears in each stage separately, revealed statistically significant difference of little clinical importance. The picture was different in amplitude measurement, which revealed significant difference between control and study group of both statistical and clinical values. Both of cVEMP and oVEMP recorded via air conduction stimulation has paralleled each other during the course of the pathology while affection of oVEMP recorded via bone conduction stimulation showed in the second stage of the disease. Conclusion oVEMP via air conduction and bone conduction stimulation was highly reproducible among normal population. oVEMP and cVEMP were affected in patients of Meniere’s disease and revealed more impairment when progressing into advancing stages.

Objective This article presents a review of the literature concerning size measurement of cervical muscles using real-time ultrasound imaging (RUSI) in patients with neck pain and in healthy populations. Methods A literature search from 1996 to December 2009 making use of Science Direct and PubMed databases was conducted. Medical Subject Headings and other terms were as follows: ultrasonography , cervical , muscle , neck , size , pain , validity , reliability , neck pain , and healthy subjects . We included studies using RUSI for assessing cervical paraspinal muscles both in healthy subjects and in patients with neck pain. We assessed muscles investigated and the reliability and validity of the method used. Results The literature search yielded 16 studies. Twelve (75%) studies assessed the posterior muscles, whereas in the remaining 4 (25%), the anterior muscles were studied. Three studies quantified the size of the muscles during contraction; 3 assessed the relationship between cross-sectional area, linear dimensions, and anthropometric variables; 1 evaluated the training-induced changes in muscle size; 1 assessed the differences in muscle shape and cross-sectional area of cervical multifidus between patients with chronic neck pain and controls; 8 studies looked at the reliability of using RUSI in patients with neck pain or healthy subjects; and 3 studies evaluated the validity of RUSI compared with magnetic resonance imaging. Conclusions This literature review has shown that there are not sufficient studies for assessing neck muscles with RUSI. It seems that using constant landmarks, knowledge of anatomy and function of target muscle, and a proper definition of muscle borders can help to take a clear image. Standardized position of the subject, correct placement of the transducer, and using multiple RUSI for statistical analyses may improve results.

Background Anterocollis is a form of cervical dystonia characterized by forward neck flexion. While botulinum toxin is the treatment of choice for cervical dystonia, patients with anterocollis, who receive injections into the sternocleidomastoid and anterior scalene muscles, represent a disproportionate number of treatment failures. Deep cervical muscles such as the longus colli likely play an important role in neck flexion but are not routinely injected. Objective To describe a technique for longus colli injection in cases of anterocollis and to report the clinical outcomes of 10 such injections of botulinum toxin. Methods Three patients were referred for evaluation and treatment of anterocollis. All had previous treatment failures with sternocleidomastoid/anterior scalene injections or no activity noted on needle EMG investigation of these muscles. All patients received injections of botulinum toxin into the longus colli under fluoroscopic and EMG guidance. Results All patients experienced symptomatic improvement (eight of 10 injections). Two patients reported mild dysphagia without serious complications after dose increases in botulinum toxin. Conclusions Incomplete muscle selection may be one cause of treatment failures in anterocollis. Deep cervical flexors such as the longus colli represent an under-recognized potential target for symptomatic treatment of anterocollis.

Both low-load and high-load training of the cervical muscles have been shown to reduce neck pain and change parameters of muscle function directly related to the exercise performed. The purpose of this study was to investigate whether either training regime changes muscle activation during a functional task which is known to be affected in people with neck pain and is not directly related to either exercise protocol. Fifty-eight female patients with chronic neck pain were randomised into one of two 6-week exercise intervention groups: an endurance-strength training regime for the cervical flexor muscles or low-load training of the cranio-cervical flexor muscles. The primary outcome was a change in electromyographic (EMG) amplitude of the sternocleidomastoid (SCM) muscle during a functional, repetitive upper limb task. At the 7th week follow-up assessment both intervention groups demonstrated a reduction in their average intensity of pain (P0.05). However, neither training group demonstrated a change in SCM EMG amplitude during the functional task (P0.05). The results demonstrate that training the cervical muscles with a prescribed motor task may not automatically result in improved muscle activation during a functional activity, despite a reduction in neck pain.

The purpose of this brief review is to present evidence from experimental and clinical neck pain studies of pain-induced neuromuscular adaptations. It has been shown that clinical neck pain is associated with a substantial reorganization in the control strategies of cervical muscles during static and dynamic tasks. Experimental neck pain models allow local elicitation of nociceptive afferents, mimicking the sensory aspects of clinical pain, without major changes in muscle properties. These models may help understand the physiological mechanisms underlying the observations from clinical neck pain studies. The knowledge obtained from the interpretation of clinical findings with experimental pain models has relevance for the development of therapeutic interventions for the rehabilitation of patients with neck pain disorders.

The mouth breathing resulting from nasal obstruction has been highly incident, mostly as a consequence of allergic rhinitis. In children, such condition is more concerned because it causes alteration during their development, which may generate deformities.To evaluate the efficacy of a program of combined postural exercise and breathing, on the cervical muscles and body posture in school-age mouth breathing children.Nineteen mouth breathing children, mean age of 10.6 years, both genders, were recruited either from a public school or from a speech-therapy service. The evaluation procedures were electromyographic recordings from the sternocleidomastoid (SCM), sub-occipitals (SOC) and upper trapezius (UT) muscles and computerized photographic analysis pre and post-treatment. The subjects were submitted to a 12-week of a Physical Therapy Program (PTP) consisted by (a) muscular stretching and strengthening exercises using a Swiss ball combined to (b) naso-diaphragmatic re-education.There was a significant reduction (p0.05) in the electrical activity on the assessed muscles during quiet position (5, 19 and 7.1% to 3, 2 and 10.3% for SCM, SOC and UT, respectively) and aligned posture (7, 19 and 8% to 4, 9 and 2.6% for SCM, SOC and UT, respectively) after treatment. Improvement in the postural deviation, especially reduction in forward head posture and abducted scapula were demonstrated in the computerized photographic analysis.A combination of postural and breathing exercises was effective in restoring muscle imbalances and posture in a group of school-age mouth breathing children, as measured by changes in electrical activity and positional data.

OBJECTIVE: The objective of this study was to determine the effect of a standard 3-point lap-and-shoulder seat belt and car seat on the electromyogram (EMG) response of the cervical muscles to increasing low-velocity impacts in comparison with that of a rigid seat and 5-point restraint. METHODS: Seventeen healthy volunteers were subjected to rear, frontal, right and left lateral and bilateral anterolateral, and posterolateral impacts with an acceleration varying from 4.4 to 16.8 m/s(2) while in a car seat with lap-and-shoulder seat belt. RESULTS: For rear-end impacts, whether straight on, right posterolateral, or left posterolateral, all muscles generated 50% or less of the maximal voluntary contraction (MVC) EMG. In straight-on rear impacts, the sternocleidomastoid was symmetrically the most active; however, in posterolateral impacts, the sternocleidomastoid contralateral to impact direction was more active than its counterpart. For a right lateral impact, at the highest acceleration, the left splenius capitis generated 47% of its MVC and the left trapezius did 46% of its MVC. In a left lateral impact, the right splenius capitis generated 48% of its MVC and the right trapezius did 57% of its MVC. In a straight-on frontal impact, the left trapezius generated 35% of its MVC and the right trapezius did 48% of its MVC. In a left anterolateral impact, the right splenius generated 60% of its MVC and the right trapezius did 66% of its MVC. Similarly, in a right anterolateral impact, the contralateral splenius muscle increased its activity to 52% of its MVC and the left trapezius was at 52% of its MVC. CONCLUSIONS: Compared with previously reported impact studies with a rigid seat and 5-point harness, the use of a 3-point lap-and-shoulder seat belt with a standard car seat did not appear to adversely affect cervical muscle response. In very-low-velocity and low-velocity impact experiments, seat belt and seat type may not significantly alter cervical EMG and kinematics. Language: en

Knowledge is increasing about the electromyographic and kinematic response of the neck muscles to rear impact, and also recent information is available on the effect of a rear impact offset to the left (posterolateral). The effect of head rotation, however, at the time of rear impact is not known.The purpose of this study was to examine the effects of head rotation to the left and right on the cervical muscle response to increasing low-velocity posterolateral impacts.Twenty healthy volunteers were subjected to rear impacts of 4.7, 8.3, 10.9 and 13.7 m/s2 acceleration, offset by 45 degrees to the subject's left, with head rotation to right and left.Bilateral electromyograms of the sternocleidomastoids, trapezii and splenii capitis were recorded. Triaxial accelerometers recorded the acceleration of the sled, torso at the shoulder level, and head of the participant.With the head rotated to the right, at an acceleration of 13.7 m/s2, the left sternocleidomastoid generated 59% and the right sternocleidomastoid 20% of their maximal voluntary contraction (MVC) electromyogram (EMG). Under these conditions, the remaining muscles (both splenii capitis and trapezius) generated 25% or less of their MVC. With the head rotated to the left, at an acceleration of 13.7 m/s2, the right sternocleidomastoid generated 65% and the left sternocleidomastoid only 11% of the MVC EMG. Under these conditions, again the remaining muscles had low EMG activity (27% or less) with the exception of the left trapezius which generated 47% of its MVC. Electromyographic variables were significantly affected by the levels of acceleration (p.01). The time to onset and time to peak EMG for all muscles progressively decreased with increasing levels of acceleration, for both head rotation conditions. The kinetic variables and the electromyographic variables regressed significantly on the acceleration (p.01).Direction of impact is a factor in determining the muscle response to whiplash, but head rotation at the time of impact is also important in this regard. More specifically, when a rear impact is left posterolateral, it results in increased EMG generation mainly in the contralateral sternocleidomastoid, as expected, but head rotation at the same time in this type of impact reduces the EMG response of the cervical muscles. Muscle injury seems less likely under these conditions in low-velocity impacts.

Although there are some volunteer collision studies reporting the effects of rear impacts on head and neck kinematics, there are few studies detailing the cervical muscle electromyogram response. Moreover, the effect of a rear impact offset to the left on the resultant muscle responses is unknown.The purpose of this study was to determine the response of the cervical muscles to increasing low-velocity rear impacts offset by 45 degrees to the subject's left, and to compare the quantitative effects of expected and unexpected impact.Nine healthy volunteers were subjected to rear impacts, offset by 45 degrees to the subject's left, of 4.6, 8.7, 11.0 and 14.5 m/s2 acceleration, at two levels of expectation: expected and unexpected.Bilateral electromyograms of the sternocleidomastoids, trapezii and splenii capitis were recorded. Triaxial accelerometers recorded the acceleration of the chair, torso at the shoulder level and head of the participant.At an acceleration of 14.5 m/s2, the left sternocleidomastoid generated 71% and the right sternocleidomastoid 82% of their maximal voluntary contraction electromyogram in the unexpected impact conditions. Under these conditions, the right splenius capitis (contralateral to the left offset rear impact) also generated 71% of its maximal voluntary contraction, whereas the left splenius capitis generated only 20% of this variable. The trapezii generated only 25% of their maximal voluntary contraction. Subjects exhibited lower levels of their maximal voluntary contraction electromyogram when the impact was expected. Electromyographic variables were significantly affected by the levels of acceleration and expectation (p.001). The time to onset and time to peak electromyogram for all muscles progressively decreased with increasing levels of acceleration, in the unexpected condition. The kinetic variables and the electromyographic variables regressed significantly on the acceleration (p.001). In response to rear impacts offset to the subject's left, muscle responses were greater with higher levels of acceleration, greater with unexpected impact conditions and greatest for both sternocleidomastoids and for the splenius capitis muscle contralateral to the side of impact.Because the muscular component of the head-neck complex plays a role in the abatement of impact at higher acceleration levels, they are likely a primary site of injury in the whiplash phenomenon in rear collisions. More specifically, when a rear impact is offset to the subject's left, it results in not only increased electromyographic generation in both sternocleidomastoids, but the splenius capitis contralateral to the direction of impact offset also bears part of the force of the neck perturbation. Expecting or being aware of imminent impact also plays a role in reducing muscle responses in low-velocity offset rear impacts.

Tension Type Headache (T.T.H) is the most prevalent headache. Myofascial abnormalities & trigger points are important in this type of headache which can be managed by Positional Release Therapy (PRT). This is a report of a 47 years old female patient with Tension Type Headache treated by Positional Release Therapy for her trigger points. She had a constant dull headache, which continued all the day for 9 months. A physiotherapist evaluated the patient and found active trigger points in her cervical muscles. Then, she received Positional Release Therapy for her trigger points. After 3 treatment sessions, the patient's headache stopped completely. During the 8 months following the treatment she was without pain, and did not use any medication. Positional Release Therapy was effective in treating Tension Type Headache. This suggests that PRT could be an alternative treatment to medication in patients with T.T.H if the effectiveness of that can be confirmed by further studies.

The objective of the study was to determine the median frequency (MF) and mean power frequency (MPF) of the stermodeidomastorial, splenius capitis and trapezius in progressively and linearly increasing isometric cervical flexion and extension. There is a dearth of data on spectral parameters of cervical muscles. Such data have been generated from 40 young adult subjects (21 male and 19 female). The subjects were seated upright in an individually adjusted chair and stabilized with a 4-point Velcro restraint system to stabilize the torso. These subjects exerted isometric flexor and extensor forces in a random sequence on an instrumented resistance device (specifically designed for the study) in a gradual and linearly increasing manner with a visual feedback to their maximal voluntary contraction (MVC) within a 5 s period. Surface EMG was sampled from the sternocleidomastoid, the splenius capitis and the trapezius muscles bilaterally at 1 kHz. The EMG signals were subjected to Fast Fourier Transform (FFT) analysis. Spectral profiles of all muscles in the dimensions of frequency, power, and grade of contraction were plotted. The mean median frequency (MF), mean power frequency (MPF), peak power and total power were analyzed. In the sternocleidomastoid, and the splenius the MF increased with the grade of contraction, widening its bandwidth at higher grades. The trapezius maintained a narrow bandwidth and its MF declined with the grade of contraction.

Objective. To assess the potential for cervical muscle injury from a rear-end automobile collision. Design . Experimental design in which human subjects were exposed to low-speed rear-end collisions. The influence of independent variable (gender, speed change, muscle group, and motion phase) on dependent variables (kinematic response, muscle onset and muscle activation level) was examined using repeated-measures analysis of variance. Background. Injuries to various tissues of the cervical spine have been proposed, yet little attention has been focused on the cervical muscles as a site of injury. Methods. 42 subjects (21 males, 20–40 yr) were exposed to collisions of 4 and 8 km/h speed change while measuring kinematic response of the head and torso and electromyography of the sternocleidomastoid and cervical paraspinal muscles. Results. Muscle activation occurred earlier in females and in the 8 km/h speed change. Sternocleidomastoid onset preceded paraspinal onset. Muscle activation level varied significantly with speed change, motion phase and muscle group. Initial rearward retraction of the head relative to the torso resulted in lengthening of the activated sternocleidomastoid, consistent with a contraction-induced muscle injury. Conclusions. The cervical muscles contract rapidly in response to impact and the potential exists for muscle injury due to lengthening contractions. Relevance The clinician should recognize the role of cervical retraction in the mechanism of whiplash injury and avoid aggressive motion in that plane during diagnosis and treatment. An understanding of whiplash injury mechanisms should improve patient education and preventative measures.

Background: In the comprehensive assessment of painful conditions, dynamic surface electromyography (sEMG) and range of motion (ROM) recordings can provide information regarding muscle spasm, antalgic postures, fear of pain (protective guarding), muscle injury, and disordered movement caused by pain. This study examines ROM and sEMG patterns observed during cervical flexion. Objective: To demonstrate 2 distinctive sEMG recruitment and dynamic ROM patterns observed during cervical flexion and return to mid-line. Design: Single-subject design with independent measurement of dynamic ROM and sEMG. Setting: Applied clinical setting. Participants: Two subjects with normal ROM and cervical muscles were studied. Main Outcome Measure: One subject was studied with sEMG, looking at the cervical paraspinals and sternocleidomastoid muscles; the other subject was studied with an active ROM device. Three cervical movements were studied: lower cervical flexion, atlantoaxial (upper) cervical flexion, and a combination upper/lower cervical flexion. Results: The active ROM device indicates larger movements (higher degress of flexion) for the lower cervical flexion compared with upper flexion. The combined movement indicates a differential movement from 2 spinal segments. The sEMG recordings indicated differential recruitment patterns. The sternoclei-domastoid recruits briskly during the flexion phase of the upper cervical flexion movement, whereas the cervical paraspinals recruit briskly during return to mid-line when the lower cervical flexion is used. The combined upper then lower cervical flexion movement recruits both sets of muscles. Conclusions: The results of the study indicate 2 distinct movement patterns associated with upper versus lower cervical flexion and 2 distinct sEMG recruitment patterns. The study suggests that these 2 distinct movements involve 2 distinct cervical segments and are associated with recruitment of different muscle groups. Applied clinical research on the cervical spine should use sEMG recordings to assess both the upper and lower flexion movements as the standard for the study of cervical flexion. (J Manipulative Physiol Ther 1999;22:570–5)

Cervical muscles of 15 cases of compression of the neck and the other traumatized skeletal muscles from 54 autopsy cases were examined histologically and immunohistochemically. Round and thick fibers, that is, opaque fibers were observed in the muscles beneath the compression marks on the neck, whereas in areas where no force had been applied, such fibers did not exist. Furthermore, opaque changes appeared around cavities, which formed within severely compressed injured muscle tissue. The pattern of appearance of opaque fibers in the cases of compression of the neck were mainly divided into two types, `diffuse' pattern and `focal' pattern. In both blunt and sharp force injuries, the production of opaque fibers were common in the area directly where damage had been inflicted. In stab wounds especially, the appearance of opaque fibers and wavelike fibers, which fanned out and showed a different color from the other areas, was limited to the marginal zone. These results suggest that there is a close relationship between opaque changes and force. Opaque fibers are probably produced by damage to muscles due to extremely applied force. The high incidence of opaque fibers beneath compression marks on the neck should be regarded as a useful indication of strangulation and/or hanging. Furthermore, the distribution and direction of force to the neck might be presumed by the pattern of opaque fibers in cervical muscles, to a certain extent.

A study was conducted on eight subjects, in order to investigate the influence of head posture with regards to the screen and copy holder position, the activity of cervical muscles and the subjective judgement given by the subjects. A total of eleven different positions (exercises) of screen and copy holder were investigated. Four different screen positions were examined in the upright (middle) sitting posture and three different screen positions were investigated in the backward sitting posture. In addition, four different positions of the copy holder were examined in the upright sitting posture. Head posture and muscle activity were continuously measured in each exercise for a duration of 5 min. At the end of each exercise, the subjects were asked how they judged the position of the screen and/or the copy holder in comparison with other positions. The results show that preference is to be given to a screen position in which the vision axis is horizontal or inclined slightly downwards. The copy holder should be arranged at one side of the screen.

Background Forward head postures (FHP) are proposed to adversely load cervical spine structures. Neck muscles provide support for the neck, and thus an imbalance in neck muscle performance could potentially contribute to the development of FHP. Previous studies have not considered the interaction of multiple muscle groups with regard to postural orientation. Given the interdependence of muscles along the cervical spine for optimal orientation and physical support of the vertebral column, the performance of a single muscle group may not accurately reflect the coordinated ability of the muscles to maintain a neutral neck posture. Purpose The purpose of this study was to investigate the relationship between FHP and the balance between the cervical extensor and flexor muscle groups in healthy individuals. We hypothesised that the magnitude of FHP would be associated with the strength and endurance performance ratios between the cervical extensor and flexor muscle groups. Methods Twenty male and 24 female volunteers were photographed in the sagittal plane wearing surface markers. The FHP of each participant was measured via the tragus-sternum marker distance over two conditions: (1)in relaxed standing and (2)during a sustained sitting task. Maximal strength (Nm) and endurance (s) performance of the extensor and flexor muscle groups were recorded at the upper (craniocervical flexion/extension (CCF/CCE)) and lower (cervicothoracic flexion/extension (CTF/CTE)) cervical regions. Muscle performance measures were expressed as extension:flexion ratios and their relation to FHP evaluated. A stepwise multiple regression analysis using backward elimination was utilised to examine the relationship between the postural measures and the muscle performance ratio measures. Separate models were used for the two different postural conditions (standing, sustained sitting). Gender was included as a constant correction factor in all regression models. Where gender was a significant variable in the model, analyses were repeated separately for males and females. Results Greater FHP in standing was significantly associated with reduced proportional CTE to CCF strength in females (R2 = 0.21, P = 0.03) and greater proportional CTE to CTF strength in males (R2 = 0.23, P = 0.03). A greater drift into FHP during sustained sitting was associated with a relative reduction in CCE endurance proportional to CTF endurance in females only (R2 = 0.27, P = 0.017). Conclusion(s) This initial study indicates that the balance in performance between the cervical flexor and extensor muscle groups may impact FHP in healthy individuals. However, the findings were inconsistent across different muscle performance ratios and gender. Larger scale studies are therefore now needed to further clarify the relationship between FHP and muscle performance. Implications The findings suggest that relative performance of the various cervical muscle groups needs to be accounted for when considering postural correction strategies in the clinical setting, as is often recommended.

Anterocollis (AC) is caused by dystonia of superficial and deep cervical muscles. Bilateral contraction of sternocleidomastoid muscles (SCM) normally leads to head retroflexion and chin protraction, but in dystonic anterior shift it leads to head anteversion. Independently, longus colli muscles (LGC) mediate cervicospinal anteflexion and head anteversion. Thus, CT-guided BoNT-A injection of the often hypertrophic LGC is proposed in AC without anterior shift. We report on 10 treatments of LGC in 7 pts. with AC as the main symptom of cervical dystonia. 3 pts. displayed anterior shift, 1 pt. posterior shift, 3 pts. no shift. TWSTRS and chin-brow vertical angle (CBVA) were assessed. Cervical CT showed asymmetric hypertrophy of LGC in pts. without shift but not in pts. with anterior shift. In the latter, bilateral treatment of SCM and anterior scalene muscles improved dystonia. In pts. without shift, treatment of superficial cervical muscles did not sufficiently improve AC, while TC responded well. In these pts., CT-guided injection of the hypertrophic LGC reduced the TWSTRS-subscore for AC by 42% and CBVA by 50%. This improvement of AC lasted longer than with treatment of superficial cervical muscles alone (up to 9 months). By contrast, in a pt. with posterior shift, LGC treatment did not prove beneficial to AC. In AC with anterior shift, SCM should be treated bilaterally, but in AC without anterior shift CT-guided BoNT-A injection of the hypertrophic LGC is strongly recommendable.

INTRODUCTION People with chronic neck pain demonstrate changes in motor control pattern [1]. The early detection of abnormal patterns is important for preventing the neck disorders. Recently, voluntary response index (VRI) is proposed as a sensitive measure of voluntary motor control in the differentiation of abnormality [2,3]. It contains the similarity index (SI) and the measurement of the magnitude of EMG activities (MAG). Although the speed is believed to significantly affect the muscle activity in extremities, there is lack of studies to examine the different speeds of cervical movements on the surface electromyographic activity (sEMG) of cervical muscles. The purpose of the study accordingly was to evaluate the effect of different speeds on the VRI of cervical muscles during different directions of movement.

Ablation of the motor cortex or section of the pyramidal tracts in dogs were studied for their effects on the performance of an alimentary instrumental reaction. The animal was required to keep its foreleg raised during feeding in order to gain access to food. The operated animals were capable of raising the leg in response to a signal and of holding it, but when snatching the food they immediately lower it. These dogs can, however, accomplish such a conditioned reflex if they do not have to lower the head during feeding. There may exist inborn reflexes from the cervical muscles or the vestibular apparatus ensuring the support on the forelegs when the head is lowered for feeding. When a new coordination including feeding with the leg raised, is elaborated, these inborn coordinations are inhibited. Evidently, inhibition of such inborn coordinations is effected through the pyramidal tract. The pyramidotomized animal is incapable of inhibiting the reation of lowering its leg when feeding with head down and cannot therefore keep its leg raised when feeding. However, there is no need of inhibiting inborn coordiantions when feeding with the head raised. For this reason pyramidotomized dogs are capable of keeping the leg raised in the latter condition.