Deep and superficial cervical muscles respond differently to unstable motor skill tasks.

Biomechanical modelling and physiological studies suggest that various spinal muscle layers differ in their contribution to spine movement and stiffness. This study aimed to investigate the activation of deep and superficial muscles in stable and unstable task conditions. Nine healthy participants performed a task of controlling a metal ball on a plate fixed to the head in seated position. In unstable tasks, visual feedback was provided by mirrors to move the ball to the centre of the plate by small head movements and maintain the position for 3 s. Task difficulty was adjusted in a stepwise progression of difficulty using five surfaces with materials of decreasing resistance. In the stable condition, the ball was fixed to the plate's centre. EMG was recorded with surface (sternocleidomastoid, anterior scalenes, upper trapezius) and fine-wire electrodes (rectus capitis posterior major, obliquus inferior, multifidus, semispinalis cervicis, splenius capitis). The outcome variable was root mean square (RMS) EMG during the part of the task when the ball was maintained in the centre position. Results revealed greater cervical muscle activity in the unstable than stable conditions (p < 0.001, ηp2 = 0.746). Control of deep and superficial cervical muscles differed (p = 0.003, ηp2 = 0.354). Deep cervical muscle activity was greater with unstable tasks, but did not differ with task difficulty. In contrast, superficial cervical muscle activity increased in a stepwise manner with increasing challenge. These results support the notion that the central nervous system uses different strategies for control of deep versus superficial muscle layers of the cervical spine in association with instability.

Can a professional development workshop with follow-up alter practitioner behaviour and outcomes for neck pain patients? A randomised controlled trial.

BACKGROUND: Continuing professional development (CPD) is a fundamental component of physiotherapy practice. Follow-up sessions provide opportunity for the refinement of skills developed during CPD workshops. However, it is necessary to identify if such opportunity translates to improved physiotherapist performance and patient outcomes. OBJECTIVES: To determine whether a traditional CPD workshop with a follow-up session with the educator is more likely to change physiotherapists' practice behaviour and patient outcomes than a traditional workshop with no opportunity for follow-up. DESIGN: A single-blind, randomised controlled trial. METHODS: Participants were stratified and randomly allocated to the intervention and control groups. The control group participated in a two-day workshop dedicated towards the management of neck disorders. The intervention group completed the two-day workshop and attended a five-hour follow-up session one month later. Outcome measures included self-reported physiotherapist practice behaviour and confidence, as well as patient clinical outcomes using the Neck Disability Index. RESULTS: While all participants exhibited changes in confidence and practice behaviours, between-group differences were not significant for any response (p > 0.05). There were also no significant differences between the groups in terms of patient outcomes (Neck Disability Index: F = 0.36, p = 0.56). CONCLUSION: A single follow-up session to a traditional workshop is insufficient to significantly influence practice behaviours or patient outcomes.

International consensus on the most useful physical examination tests used by physiotherapists for patients with headache: A Delphi study.

BACKGROUND: A wide range of physical tests have been published for use in the assessment of musculoskeletal dysfunction in patients with headache. Which tests are used depends on a physiotherapist's clinical and scientific background as there is little guidance on the most clinically useful tests. OBJECTIVES: To identify which physical examination tests international experts in physiotherapy consider the most clinically useful for the assessment of patients with headache. DESIGN/METHODS: Delphi survey with pre-specified procedures based on a systematic search of the literature for physical examination tests proposed for the assessment of musculoskeletal dysfunction in patients with headache. RESULTS: Seventeen experts completed all three rounds of the survey. Fifteen tests were included in round one with eleven additional tests suggested by the experts. Finally eleven physical examination tests were considered clinically useful: manual joint palpation, the cranio-cervical flexion test, the cervical flexion-rotation test, active range of cervical movement, head forward position, trigger point palpation, muscle tests of the shoulder girdle, passive physiological intervertebral movements, reproduction and resolution of headache symptoms, screening of the thoracic spine, and combined movement tests. CONCLUSIONS: Eleven tests are suggested as a minimum standard for the physical examination of musculoskeletal dysfunctions in patients with headache.

Movement-based subgrouping in low back pain: synergy and divergence in approaches.

BACKGROUND: Classification systems for low back pain (LBP) aim to guide treatment decisions. In physiotherapy, there are five classification schemes for LBP which consider responses to clinical movement examination. Little is known of the relationship between the schemes. OBJECTIVES: To investigate overlap between subgroups of patients with LBP when classified using different movement-based classification schemes, and to consider how participants classified according to one scheme would be classified by another. DESIGN: Cross-sectional cohort study. SETTING: University clinical laboratory. PARTICIPANTS: One hundred and two participants with LBP were recruited from university, hospital outpatient and private physiotherapy clinics, and community advertisements. INTERVENTION: Participants underwent a standardised examination including questions and movement tests to guide subgrouping. MAIN OUTCOME MEASURES: Participants were allocated to a LBP subgroup using each of the five classification schemes: Mechanical Diagnosis and Treatment (MDT), Movement System Impairment (MSI), O'Sullivan Classification (OSC), Pathoanatomic Based Classification (PBC) and Treatment Based Classification (TBC). RESULTS: There was concordance in allocation to subgroups that consider pain relief from direction-specific repeated spinal loading in the MDT, PBC and TBC schemes. There was consistency of subgrouping between the MSI and OSC schemes, which consider pain provocation to specific movement directions. Synergies between other subgroups were more variable. Participants from one subgroup could be subdivided using another scheme. CONCLUSIONS: There is overlap and discordance between LBP subgrouping schemes that consider movement. Where overlap is present, schemes recommend different treatment options. Where subgroups from one scheme can be subdivided using another scheme, there is potential to further guide treatment. An integrated assessment model may refine treatment targeting.

Inter-and intra-tester reliability of a battery of cervical movement control dysfunction tests.

BACKGROUND: Apart from the cranio-cervical flexion test and the deep neck flexor endurance test, evidence related to reliability of cervical movement control dysfunction tests is lacking. OBJECTIVES: This study investigated the inter- and intra-tester reliability of a battery of cervical movement control dysfunction tests and the effect of clinician experience on reliability in 15 patients with chronic neck pain and 17 non-neck pain controls. In addition, it explored whether impaired performance on this battery of tests was more frequently observed in the neck pain group. DESIGN: Inter and intra-tester reliability study. METHOD: Participants were videotaped while performing a battery of nine active cervical movement control dysfunction tests. Two physiotherapists, with different levels of experience, independently rated all tests on two occasions two weeks apart. They were masked to participants' neck pain or non-neck pain status. RESULTS: Inter-tester reliability for the complete battery of tests was substantial (κ = 0.69; 95% CI: 0.62, 0.76). Intra-rater reliability values for the expert (κ = 0.86; 95% CI: 0.79, 0.92) and novice (κ = 0.76; 95% confidence intervals (CI): 0.68, 0.84) were overall comparable suggesting that novices can achieve good accuracy with the battery of tests if trained. The frequency of impaired performances in cervical movement control dysfunction tests was low and comparable between groups. Only two tests achieved a greater number of impaired ratings in the patient group. CONCLUSIONS: Although reliable, further research in larger neck pain populations is required to explore this battery of tests, in order to establish their diagnostic accuracy for identifying clinically relevant cervical movement control dysfunction.

Preliminary evaluation of dorsal muscle activity during resisted cervical extension in patients with longstanding pain and disability following anterior cervical decompression and fusion surgery.

OBJECTIVES: To compare mechanical activity (deformation and deformation rate) of the dorsal neck muscles between individuals with longstanding symptoms after anterior cervical decompression and fusion (ACDF) surgery and healthy controls. DESIGN: Preliminary cross-sectional study. SETTING: Neurosurgery clinic. PARTICIPANTS: Ten individuals {mean age 60 [standard deviation (SD) 7.1]} who had undergone ACDF surgery 10 to 13 years previously and 10 healthy age- and sex-matched controls. MAIN OUTCOMES: Mechanical activity of the different layers of dorsal neck muscles, measured at the C4 segment using ultrasonography (speckle tracking analysis) during a standardised, resisted cervical extension task. RESULTS: A significant group×muscle interaction was found for muscle deformation (P<0.03) but not for deformation rate (P>0.79). The ACDF group showed significantly less deformation of the semispinalis capitis muscle during the extension task compared with the control group [mean 3.12 (SD 2.06) and 6.64 (SD 4.17), respectively; mean difference 3.34 (95% confidence interval -0.54 to 7.21)]. CONCLUSIONS: As the semispinalis capitis muscle is a powerful neck extensor, the finding of altered activation following ACDF surgery lends support to the inclusion of exercise to train neck muscle performance in the management of these patients.

Enhancing the vocational outcomes of people with chronic disabilities caused by a musculoskeletal condition: development and evaluation of content of self-management training modules.

BACKGROUND: No self-management interventions have been developed to empower those chronically disabled by a musculoskeletal condition to find and/or remain at work. OBJECTIVE: Developand evaluate the content of two self-management training modules to improve vocational outcomes for those with chronic musculoskeletal disorders. METHODS: Stanford University's Chronic Disease Self-Management Program provided the framework for the new modules. Focus groups with the eightpersons with workdisabilities and concept-mapping sessions with the 12 experienced vocational rehabilitation professionals were conducted to identify factors and themes contributing to workers remaining/returning to work post-injury. Five experienced self-management trainers reviewed the modules for consistency with self-management principles. RESULTS: Two new self-management modules: 'Navigating the System' and 'Managing a Return to Work' were developed.The persons with work disabilitiesgenerated four themes: accepting and coping with injury; skills to manage pain and life; positive working relationships and, re-inventing self, whereas the rehabilitation professionals identified three themes:communication and support of others; the injured worker's abilities and resources, and knowledge and education. CONCLUSIONS: Anintervention developed to enhance self-management skills and facilitate positive vocational outcomes of those seeking to return to work post-injury was confirmed as relevant by persons with work disabilities, rehabilitation professionals and self-management trainers.

Interactive effects from self-reported physical and psychosocial factors in the workplace on neck pain and disability in female office workers.

This study explored the interaction between physical and psychosocial factors in the workplace on neck pain and disability in female computer users. A self-report survey was used to collect data on physical risk factors (monitor location, duration of time spent using the keyboard and mouse) and psychosocial domains (as assessed by the Job Content Questionnaire). The neck disability index was the outcome measure. Interactions among the physical and psychosocial factors were examined in analysis of covariance. High supervisor support, decision authority and skill discretion protect against the negative impact of (1) time spent on computer-based tasks, (2) non-optimal placement of the computer monitor and (3) long duration of mouse use. Office workers with greater neck pain experience a combination of high physical and low psychosocial stressors at work. Prevention and intervention strategies that target both sets of risk factors are likely to be more successful than single intervention programmes. STATEMENT OF RELEVANCE: The results of this study demonstrate that the interaction of physical and psychosocial factors in the workplace has a stronger association with neck pain and disability than the presence of either factor alone. This finding has important implications for strategies aimed at the prevention of musculoskeletal problems in office workers.

The effect of therapeutic exercise on activation of the deep cervical flexor muscles in people with chronic neck pain.

Deep cervical flexor muscle (DCF) activation is impaired with neck pain. This study investigated the effects of low load cranio-cervical flexion (C-CF) and neck flexor strengthening exercises on spatial and temporal characteristics of DCF activation during a neck movement task and a task challenging the neck's postural stability. Forty-six chronic neck pain subjects were randomly assigned to an exercise group and undertook a 6-week training program. Electromyographic (EMG) activity was recorded from the DCF, sternocleidomastoid (SCM) and anterior scalene (AS) muscles pre and post intervention during the cranio-cervical flexion test (CCFT) and during perturbations induced by rapid, unilateral shoulder flexion and extension. C-CF training increased DCF EMG amplitude and decreased SCM and AS EMG amplitude across all stages of the CCFT (all P<0.05). No change occurred in DCF EMG amplitude following strength training. There was no significant between group difference in pre-post intervention change in relative latency of DCF but a greater proportion of the C-CF group shortened the relative latency between the activation of the deltoid and the DCF during rapid arm movement compared to the strength group (P<0.05). Specific low load C-CF exercise changes spatial and temporal characteristics of DCF activation which may partially explain its efficacy in rehabilitation.

Fatty infiltrate in the cervical extensor muscles is not a feature of chronic, insidious-onset neck pain.

AIM: To investigate the presence of fatty infiltrate in the cervical extensor musculature in patients with insidious-onset neck pain to better understand the possible pathophysiology underlying such changes in chronic whiplash-associated disorders (WAD). MATERIALS AND METHODS: A sample of convenience of 23 women with persistent insidious-onset neck pain (mean age 29.2+/-6.9 years) was recruited for the study. Magnetic resonance imaging (MRI) was used to quantify fatty infiltration in the cervical extensor musculature. Quantitative Sensory Testing (QST; pressure and thermal pain thresholds) was performed as sensory features are present in chronic whiplash. Self-reported pain and disability, as well as psychological distress, were measured using the Neck Disability Index (NDI) and the General Health Questionnaire-28 (GHQ-28), respectively. RESULTS: Measures were compared with those of a previous dataset of chronic whiplash patients (n=79, mean age 29.7+/-7.8 years). Using a classification tree, insidious-onset neck pain was clearly identified from whiplash (p<0.001), based on the presence of MRI fatty infiltrate in the cervical extensor musculature (0/102 individuals) and altered temperature thresholds (cold; 3/102 individuals). CONCLUSION: Fatty infiltrates in the cervical extensor musculature and widespread hyperalgesia were not features of the insidious-onset neck pain group in this study; whereas these features have been identified in patients with chronic WAD. This novel finding may enable a better understanding of the underlying pathophysiological processes in patients with chronic whiplash.

Neck movement and muscle activity characteristics in female office workers with neck pain.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To explore aspects of cervical musculoskeletal function in female office workers with neck pain. SUMMARY OF BACKGROUND DATA: Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. METHODS: Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocervical flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. RESULTS: Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers' self-reported levels of pain and disability and the movement and muscle changes. CONCLUSION: These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.

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

This study determined differences between computer workers with varying levels of neck pain in terms of work stressors, employee strain, electromyography (EMG) amplitude and heart rate response to various tasks. Participants included 85 workers (33, no pain; 38, mild pain; 14, moderate pain) and 22 non-working controls. Work stressors evaluated were job demands, decision authority, and social support. Heart rate was recorded during three tasks: copy-typing, typing with superimposed stress and a colour word task. Measures included electromyography signals from the sternocleidomastoid (SCM), anterior scalene (AS), cervical extensor (CE) and upper trapezius (UT) muscles bilaterally. Results showed no difference between groups in work stressors or employee strain measures. Workers with and without pain had higher measured levels of EMG amplitude in SCM, AS and CE muscles during the tasks than controls (all P < 0.02). In workers with neck pain, the UT had difficulty in switching off on completion of tasks compared with controls and workers without pain. There was an increase in heart rate, perceived tension and pain and decrease in accuracy for all groups during the stressful tasks with symptomatic workers producing more typing errors than controls and workers without pain. These findings suggest an altered muscle recruitment pattern in the neck flexor and extensor muscles. Whether this is a consequence or source of the musculoskeletal disorder cannot be determined from this study. It is possible that workers currently without symptoms may be at risk of developing a musculoskeletal disorder.

Conservative treatments for tennis elbow do subgroups of patients respond differently?

OBJECTIVES: To determine if subgroups of patients with tennis elbow respond differently in treatment. METHODS: This study used individual patient data (n = 383) from two randomized controlled trials that investigated a wait-and-see policy, corticosteroid injections and physiotherapy. Common outcome measures were: pain severity, global improvement, severity assessed by a blinded assessor, elbow disability and pain free grip strength. Subgroup analyses for previous history of elbow pain, baseline pain severity, duration of the current episode and employment status were performed at 6 and 52 weeks. RESULTS: Patients' age, previous elbow symptoms and baseline pain severity were similar between trials, but other characteristics differed between trial populations. Based on individual patient data from both trials, we found that corticosteroid injections were statistically and clinically superior at 6 weeks, but significantly worse at 52 weeks compared with both wait-and-see and physiotherapy. Subgroup effects were scarce and small. Patients with higher baseline pain score showed less benefit on pain outcomes between physiotherapy and a wait-and-see policy at 6 weeks. It also appeared that non-manual workers who had an injection were the only work subgroup to follow the general trend that injections were significantly worse than a wait-and-see policy on global improvement at 52 weeks. CONCLUSION: The treatment outcomes were largely similar between trials and not different between most subgroups studied. In tennis elbow, it would appear that patient characteristics play only a small role in predicting treatment outcomes, which supports the generalizability of individual trial results.

Cervical musculoskeletal impairment in frequent intermittent headache. Part 2: subjects with concurrent headache types.

A pattern of musculoskeletal impairment inclusive of upper cervical joint dysfunction, combined with restricted cervical motion and impairment in muscle function, has been shown to differentiate cervicogenic headache from migraine and tension-type headache when reported as single headaches. It was questioned whether this pattern of cervical musculoskeletal impairment could discriminate a cervicogenic headache as one type of headache in more complex situations when persons report two or more headaches. Subjects with two or more concurrent frequent intermittent headache types (n = 108) and 57 non-headache control subjects were assessed using a set of physical measures for the cervical musculoskeletal system. Discriminant and cluster analyses revealed that 36 subjects had the pattern of musculoskeletal impairment consistent with cervicogenic headache. Isolated features of physical impairment, e.g. range of movement (cervical extension), were not helpful in differentiating cervicogenic headache. There were no differences in measures of cervical musculoskeletal impairment undertaken in this study between control subjects and those classified with non-cervicogenic headaches.

Cervical musculoskeletal impairment in frequent intermittent headache. Part 1: Subjects with single headaches.

Musculoskeletal disorders are considered the underlying cause of cervicogenic headache, but neck pain is commonly associated with migraine and tension-type headaches. This study tested musculoskeletal function in these headache types. From a group of 196 community-based volunteers with headache, 73 had a single headache classifiable as migraine (n = 22), tension-type (n = 33) or cervicogenic headache (n = 18); 57 subjects acted as controls. Range of movement, manual examination of cervical segments, cervical flexor and extensor strength, the cranio-cervical flexion test (CCFT), cross-sectional area of selected extensor muscles at C2 (ultrasound imaging) and cervical kinaesthetic sense were measured by a blinded examiner. In all but one measure (kinaesthetic sense), the cervicogenic headache group were significantly different from the migraine, tension-type headache and control groups (all P < 0.001). A discriminant function analysis revealed that collectively, restricted movement, in association with palpable upper cervical joint dysfunction and impairment in the CCFT, had 100% sensitivity and 94% specificity to identify cervicogenic headache. There was no evidence that the cervical musculoskeletal impairments assessed in this study were present in the migraine and tension-type headache groups. Further research is required to validate the predictive capacity of this pattern of impairment to differentially diagnose cervicogenic headache.

Does the presence of sensory hypersensitivity influence outcomes of physical rehabilitation for chronic whiplash?--A preliminary RCT.

Patients with chronic whiplash associated disorders present with varied sensory, motor and psychological features. In this first instance it was questioned whether a multimodal program of physical therapies was an appropriate management to be broadly prescribed for these patients when it was known that some would have sensory features suggestive of a notable pain syndrome. A randomised controlled trial was conducted with 71 participants with persistent neck pain following a motor vehicle crash to explore this question. Participants were randomly allocated to receive either a multimodal physiotherapy program (MPT) or a self-management program (SMP) (advice and exercise). In the randomisation process, participants were stratified according to the presence or not of widespread mechanical or cold hyperalgesia. The intervention period was 10 weeks and outcomes were assessed immediately following treatment. Even with the presence of sensory hypersensitivity in 72.5% of subjects, both groups reported some relief of neck pain and disability (Neck Disability Index) and it was superior in the group receiving multimodal physiotherapy (p=0.04). Post-hoc observations however suggested that relief was marginal in the subgroup with both widespread mechanical and cold hyperalgesia. Further research is required to test the validity of this sub-group observation and to test the effect of the intervention in the long term.

Magnetic resonance imaging study of cross-sectional area of the cervical extensor musculature in an asymptomatic cohort.

Magnetic Resonance Imaging (MRI) can be regarded as the gold standard for muscle imaging; however there is little knowledge about in vivo morphometric features of neck extensor muscles in healthy subjects and how muscle size alters across vertebral segments. It is not known how body size and activity levels may influence neck muscle cross-sectional area (CSA) or if the muscles differ from left and right. The purpose of this study was to establish relative CSA (rCSA) data for the cervical extensor musculature with a reliable MRI measure in asymptomatic females within a defined age range and to determine if side-side and vertebral level differences exist. MRI of the cervical spine was performed on 42 asymptomatic female subjects within the age range of 18-45. The rCSA values for the cervical extensor muscles were measured from axial T1-weighted images. We found significant side-side rCSA differences for the rectus capitis posterior minor, major (P < 0.001), multifidus (P = 0.002), and the semispinalis cervicis/capitis (P = 0.001, P < 0.001). There were significant vertebral level differences in rCSA of the semispinalis cervicis/capitis, multifidus, splenius capitis, and upper trapezius (P < 0.001). Activity levels were shown to impact on the size of semispinalis cervicis (P = 0.027), semispinalis capitis (P = 0.003), and the splenius capitis (P = 0.004). In conclusion, measuring differences in neck extensor muscle rCSA with MRI in an asymptomatic population provides the basis for future study investigating relationships between muscular atrophy and symptoms in patients suffering from persistent neck pain. Clin.

An endurance-strength training regime is effective in reducing myoelectric manifestations of cervical flexor muscle fatigue in females with chronic neck pain.

OBJECTIVE: The purpose of this study was to investigate whether an endurance-strength training program is effective in reducing myoelectric manifestations of sternocleidomastoid (SCM) and anterior scalene (AS) muscle fatigue which have been found to be greater in people with chronic neck pain. METHODS: Fifty-eight female patients with chronic non-severe neck pain were randomized into one of two 6-week exercise intervention groups: an endurance-strength training regime for the cervical flexor muscles or a referent exercise intervention involving low load retraining of the cranio-cervical flexor muscles. The primary outcomes were a change in maximum voluntary contraction (MVC) force and change of the initial value and rate of change of the mean frequency, average rectified value and conduction velocity detected from the SCM and AS muscles during sub-maximal isometric cervical flexion contractions at 50, 25 and 10% MVC. RESULTS: At the 7th week follow-up assessment, the endurance-strength training group revealed a significant increase in MVC force and a reduction in the estimates of the initial value and rate of change of the mean frequency for both the SCM and AS muscles (P<0.05). Both exercise groups reported a reduced average intensity of neck pain and reduced neck disability index score (P<0.05). CONCLUSIONS: An endurance-strength exercise regime for the cervical flexor muscles is effective in reducing myoelectric manifestations of superficial cervical flexor muscle fatigue as well as increasing cervical flexion strength in a group of patients with chronic non-severe neck pain. SIGNIFICANCE: Provision of load to challenge the neck flexor muscles is required to reduce the fatigability of the SCM and AS muscles in people with neck pain. Improvements in cervical muscle strength and reduced fatigability may be responsible for the reported efficacy with this type of exercise program.