Students in vocational education to become electricians have an increased risk of developing musculoskeletal disorders (MSDs) once in the workforce compared to most other blue collar professions (Toomingas et al., 2014). This increased risk comes from having to work in awkward body positions, with heavy and sometimes poorly adapted tools and with time constraints. Many end up with chronic disabilities, forcing them to change careers or to go on sickness pension. Besides the significant and damaging consequences for the individual concerned, losing electricians from the workforce is a significant loss for the building industry in which electricians these days are scarce, and for society that not only loses tax-incomes but also possibly need to pay sickness pension for these people during quite a few years. It is therefore important to find ways to prevent MSDs and to promote good ergonomics in the building industry in general and among electricians specifically. Electricians’ knowledge and habits regarding MSDs are first formed and shaped in school, during vocational education to become an electrician. Drawing on the ideas of bio-power and governmentality, as introduced and developed by Foucault (1988, 1990, 2003) and developed by Rose (1999; Rabinow and Rose, 2006), discourses govern how it is possible to think and act. From this standpoint, then, talk and discourses are not perceived as innocent or ‘mere’ talk (Hall, 2001) but as governing the production, regulation and representation of both bodies and subjects through the acquisition of specific dispositions, tastes and abilities (Foucault, 1988; Rose, 1999). Thus, discourses drawn on in school about electricians and the profession govern how it is possible to think and act about oneself and others in relation to both ergonomics and MSD and, by extension, have material effects on electricians’ health. This means that, to foster healthy ergonomics one needs to consider how electricians and the profession are conceived and thought about in school, i.e. how electricians and the profession are discursively conceived. The purpose of this paper is thus to explore discursive constructions of electricians and the profession as these are expressed in discussions about MSDs in the vocational education and school context. Methods used are four focus group interviews: two with students, one with teachers and one with school management at one senior high school program for electricians. In the focus group interviews the participants were asked to discuss ideas about causes and reasons to why electricians develop MSDs, consequences and effects of MSDs and ideas about what could be done to prevent MSDs. The interviews were then transcribed and discursively analyzed with questions in mind about how each group conceived of electricians and the profession.

Electricians have an increased risk of developing musculoskeletal disorders (MSDs) compared to most other blue collar professions. Many end up with chronic disabilities, forcing them to change careers or to go on sickness pension. Besides negative consequences for the individuals concerned, MSDs also have a detrimental impact on the workforce (reduced number of professionals) and on society (financial costs). It is therefore important to find ways to prevent MSDs and to promote good ergonomic behavior. Electricians’ knowledge and habits regarding MSDs are first formed and shaped in school, during vocational education to become an electrician. In the course of this time the students have periods of internship during which they interact with professionals within the field. Drawing on the ideas of bio-power and governmentality, as introduced and developed by Foucault and developed further by Rose, discourses govern how it is possible to think and act. From this standpoint, then, talk and discourses are not perceived as innocent or ‘mere’ talk but as producing and regulating subjects through their acquisition of specific dispositions, tastes and abilities. Thus, discourses drawn on about electricians and the profession during the students’ internship will govern how it is possible for the students to think and act about themselves and others in relation to both ergonomic behavior and MSDs and, by extension, will have material effects on electricians’ health. This means that, to foster healthy ergonomic behavior one needs to consider how electricians are thought of within the field, i.e. how electricians and the profession are discursively conceived. The purpose of this paper is thus to explore discursive constructions of electricians and the profession as these were expressed in discussions about MSDs among professionals in the field.  Two semi-structured focus group interviews and one individual interview with professionals in the field were conducted. The participants were asked to discuss ideas about i) causes as to why electricians develop MSDs, ii) consequences and effects of MSDs, and iii) ideas about what could be done to prevent MSDs. The interviews were transcribed and the material is currently being discursively analyzed with questions in mind about how the participants conceived of electricians and the profession. Results will be presented at the conference, but preliminary analyses suggests that predominant discourses are concerned with the masculinity of electricians as well as with their time pressured work situation, both contributing to casualness towards ergonomic behavior.

Repetitive work to fatigue is soundly associated with work-related musculoskeletal disorders (WMSD), although the underlying mechanisms are poorly understood. In the present study, we tested the hypothesis that fatiguing work leads to proprioceptive deficits, which can be an initiating factor for the occurrence of WMSD. Thus, the position sense of the shoulder was determined for 13 males and 13 females before and after performing repetitive low-intensity arm work to fatigue in a simulated occupational setting. From a starting position of 45grader to the sagittal plane, position sense tests consisted of subjects attempting to actively reproduce target positions of horizontal move- ments to 15grader and 30grader (shoulder adduction) and to 60grader and 75grader (shoulder abduction). An analysis of variance revealed that the absolute error was significantly increased following fatigue for the subjects as a group (P < 0.001). Furthermore, females had an overall higher error than males (P < 0.01). No difference in error was detected for the shorter movements versus the longer movements. However, the overall absolute error for adduction was significantly higher than for abduc- tion (P < 0.001). The results of the present study support the hypothesis of diminished proprioceptive acuity following low-intensity work to fatigue. A reduction in position sense acuity could lead to impairment in motor control, which would further impact on position sense. Thus, a vicious cycle may be activated that might result in WMSD. The poorer position sense acuity observed for females may contribute to the explanation of why females may contribute to explanation of why females demonstrate a higher incidence of WMSD than males. Key Words: Fatigue, Glenohumeral joint, human, Occupational musculoskeletal problems,Proprioception.

Position sense awareness of the shoulder was determined for 9 males and 9 females before and after performing repetitive low-level arm activity to fatigue. The activity consisted of continuous horizontal internal and external rotations. Position sense awareness tests were performed with subjects blindfolded and seated with the arm in a motorized rig. The subjects were asked to actively reproduce test positions of 10°, 25°, 55° and 70° randomly assigned, while starting at 40° (relative to the sagittal plane). The tests were conducted immediately before and after the fatiguing activity. An ANOVA revealed that the absolute error, measured as test position minus reproduced position, was significantly increased following fatigue for the subjects as a group (p<0.001 ). Furthermore, females had overall higher error than males (p<0.05). The results indicate that repetitive low-level activity to fatigue leads to proprioceptive deficits. These deficits can create a non-optimized motor control, causing an increase in the co-activation of agonist and antagonist muscles and thus increasing the work-load. This could create an unfavorable cycle of events, which would further impact proprioception and thereby enhance the risks for muscle pain and injury. The higher incidence of injuries for female athletes compared to males may be attributed to gender differences in proprioception.

Context: Stretching is common within sports as a potential maneuver for injury prevention. Stretching induced changes in muscle spindIe properties is a suggested mechanism. This may imply a reduction in proprioception following stretching, however, little is known of this association. Our finding showing no effect of acute stretching on shoulder position sense provides insight into this issue.

Objectives: To evaluate if acute stretching of the shoulder muscles affects position sense.

Design: A crossover design with subjects randomized to 3 groups, as regarded by the I sequence of 3 interventions.

Setting: A university human research laboratory.

Patients or Other participants: Nine female (age, 21 +2) and 9 male (24 + 3) healthy volunteers.

lntervention(s): The interventions consisted of stretching of shoulder 1) agonists, 2) antagonists, and 3) non-stretching control.

Main Outcome Measure(s): Position sense acuity of the right shoulder was determined before and arter the interventions by subjects at tempting to reproduce arm positions of 15° and 30° (shoulder adduction) while starting at 45° to the sagittal plane. The outcome variables were the response variability (variable error, VE) and overall accuracy (absolute error, AE).

Results: A multivariate repeated measures analysis ofvariance revealed that the relative change in VE (i.e., VE after/VE before) was not significantly different between the interventions (p = 0.38). Similarly no change in AE was found (p = 0.76). Furthermore, there were no differences regarding test sequence or in the interaction 'intervention x sequence' for either VE (p = 0.73 and 0.53, respectively) or for AE (p = 0.71 and 0.67, respectively)

Conclusions: The present study showed no effect on shoulder position sense after an acute bout of stretching either agonist or antagonist shoulder muscles.

Background

A major problem with rehabilitation interventions for neck pain is that the condition may have multiple causes, thus a single treatment approach is seldom efficient. The present study protocol outlines a single blinded randomised controlled trial evaluating the effect of tailored treatment for neck-shoulder pain. The treatment is based on a decision model guided by standardized clinical assessment and functional tests with cut-off values. Our main hypothesis is that the tailored treatment has better short, intermediate and long-term effects than either non-tailored treatment or treatment-as-usual (TAU) on pain and function. We sub-sequentially hypothesize that tailored and non-tailored treatment both have better effect than TAU.

Methods

120 working women with minimum six weeks of nonspecific neck-shoulder pain aged 20-65, are allocated by minimisation with the factors age, duration of pain, pain intensity and disability in to the groups tailored treatment (T), non-tailored treatment (NT) or treatment-as-usual (TAU). Treatment is given to the groups T and NT for 11 weeks (27 sessions evenly distributed). An extensive presentation of the tests and treatment decision model is provided. The main treatment components are manual therapy, cranio-cervical flexion exercise and strength training, EMG-biofeedback training, treatment for cervicogenic headache, neck motor control training. A decision algorithm based on the baseline assessment determines the treatment components given to the each participant of T- and NT-groups. Primary outcome measures are physical functioning (Neck Disability Index) and average pain intensity last week (Numeric Rating Scale). Secondary outcomes are general improvement (Patient Global Impression of Change scale), symptoms (Profile Fitness Mapping neck questionnaire), capacity to work in the last 6 weeks (quality and quantity) and pressure pain threshold of m. trapezius. Primary and secondary outcomes will be reported for each group with effect size and its precision.

Discussion

We have chosen not to include women with psychological ill-health and focus on biomedical aspects of neck pain. Future studies should aim at including psychosocial aspects in a widened treatment decision model. No important adverse events or side-effects are expected. Trial registration: Current Controlled Trials registration ISRCTN49348025. Key words: Neck, trapezius, myalgia, neck-shoulder pain, RCT, individualized treatment, rehabilitation, physiotherapy, tailored

Aim of the investigation: The evidence for physiotherapy treatments of nonspecific neck pain is modest despite a large increase of intervention studies the last decade. One reason could be different underlying causes for pain in individuals with nonspecific neck pain, and that identification of sub-groups or individual needs is seldom accounted for in studies. In the absence of causal treatment options, a tailored treatment approach based on an explicit clinical decision model guided by assessment of function, clinical signs and symptoms, should be considered. Our aim was to evaluate tailored treatment based on such a decision model, targeting women with nonspecific neck pain. Our main hypothesis was that the tailored treatment (T) would have better short, intermediate and long-term effects on pain intensity and pressure pain threshold for the trapezius muscles than either non-tailored treatment (NT) (same treatment components but applied quasi-randomly) or treatment-as-usual (TAU) (no treatment from the study, no restrictions). We further hypothesized that T or NT has better effect than TAU. For details, cf. Current Controlled Trials registration ISRCTN49348025 and published study protocol.

Methods: 120 working women with minimum six weeks duration of neck pain were randomized to the T, NT or TAU groups. All participants had more than “no disability” but less than “complete disability” according to the Neck Disability Index, and reported impaired capacity on the quality or quantity to work the preceding month. Main exclusion criteria were trauma-related neck pain, specific diagnoses and generalized pain or concomitant low back pain. The decision model for tailored treatment was based on tests and symptoms with defined cut-off levels comprising the following main categories: reduced cervical mobility, impaired neck-shoulder strength and motor control, trapezius myalgia, cervicogenic headache and impaired eye-head-neck control (cf. published study protocol). Assessment was performed one week before and after the 11-weeks intervention, with follow-ups 6-months (intermediate-term) and 12-months (long-term) after the intervention. Outcome variables were pain intensity (Numeric Rating Scale, NRS, 0 – 10) and pressure pain threshold (PPT) of the upper trapezius muscles (kPa). PPT was not measured at long-term follow-up.  Preliminary statistical analyses for the predefined hypotheses were performed with analysis of covariance (ANCOVA) with baseline outcome values as covariates. This was supplemented with pairwise Bonferroni-compensated comparisons in case of significance of factor group.

Results: 86% of the participants completed the intervention, and the attrition was similar across groups. Preliminary results for the short term evaluation showed a reduction in NRS from an average of 4.4 and 4.5 to 2.5 in the T and NT groups, respectively, which was significantly greater compared to the TAU group (p=0.024 and p=0.014 for T and NT). For the PPT, there was no difference between T and NT groups at the short term evaluation, but close to a significantly increased threshold for the T compared to the TAU group (p=0,058). No differences were found between treatment groups on the intermediate and long-term evaluations for neither of the two outcome variables.

Conclusions: The results indicate that tailored treatment for women with nonspecific neck pain may not be more effective, with respect to pain reduction, compared to non-tailored treatment. The hypothesis of superiority of tailored or non-tailored treatment over treatment-as-usual was partly supported for the short-term evaluation. However, the short-term results should be interpreted with caution since the impact of higher attention given to the participants in T and NT groups is not known. Reference:1. Björklund M, Djupsjöbacka M, Svedmark Å, Häger C. (2012) Effects of tailored neck-shoulder pain treatment based on a decision model guided by clinical assessments and standardized functional tests. A study protocol of a randomized controlled trial. BMC Musculoskeletal Disorders. May 20;13(1):75

Denna skrift vänder sig till dig som har ständig värk i rygg eller nacke, eller som vid flera tillfällen haft en diffus smärta i rygg eller nacke. Här kan du läsa om vilka åtgärder forskare rekommenderar och vad du själv kan göra för att minska värken. Forskningen om vilka åtgärder som hjälper har gjort framsteg och även för dig som haft långvarig värk finns det goda möjligheter att minska smärtan.

Background: Cervical strength and stability is often addressed in rehabilitation of people with neck pain. These functions may be associated with emergence and retention of neck pain in cases where the neck strength does not meet daily demands. However, clear empiric support for these notions are lacking, partly due to a scarcity of well controlled dynamometry studies with large samples. First, clarification is needed whether neck strength is in fact reduced in people with neck pain and to resolve the diagnostic performance of neck strength tests.

Purpose: To compare neck muscle strength of women with non-specific long-term neck pain and healthy controls. Also, to assess the diagnostic performance of neck strength tests by assessing their discriminative ability to discern women with and without neck pain.

Methods: The study had a cross-sectional design with data on cervical strength derived from the baseline measurement of a randomized controlled trial (RCT). 80 women with long-term non-specific neck pain (NP) were compared with 40 healthy women (CON). The NP group was a subsample from the RCT selected so that there were no group differences (NP-CON) for body weight and physical activity. Cervical strength assessment included dynamometry of cervico-thoracic extension (CTE) and flexion (CTF) in sitting and cranio-cervical flexion (CCF) in standing, all performed with isometric maximum voluntary contraction (iMVC). Independent samples Mann-Whitney U test and T-test were used to assess group differences for iMVC of the tests. Diagnostic accuracy was further assessed with a receiver operating characteristic (ROC) curve by plotting the true positive rate (sensitivity) as a function of the false positive rate (1 - specificity). The area under the ROC curve (AUC) with 95% confidence interval was used to determine discriminative ability of the tests. The optimal cut-off value to discern NP from CON with corresponding sensitivity and specificity was also determined.

Results: Women with neck pain produced significant lower iMVC in CTE (28%), CTF (26%) and CCF (33%) (all p< 0.001). The ability of CTE, CTF and CCF to discriminate between NP and CON showed moderate accuracy (AUC 0.83, 0.78 and 0.73, respectively). The cut-off value of 165.7 N in CTE had a sensitivity of 0.725 and a specificity of 0.8. The corresponding values for CTF and CCF were 85.8 N (sensitivity 0.8; specificity 0.692) and 4.2 Nm (sensitivity 0.575; specificity 0.9).

Conclusion(s): The neck pain group had less neck muscle strength than controls in all tests. The diagnostic performance of the neck strength tests, judged as discriminative ability to discern neck pain from control participants, were moderate. These results support earlier findings of reduced neck strength in people with neck pain. Also, neck strength tests may have a complementary value in the assessment of neck pain persons.

Implications: The results highlights that impaired neck strength, both in global cervico-thoracic and deep cranio-cervical muscles, is most likely a characteristic of people with long-term neck pain. The study also shows that strength tests could be used with fairly good discriminative precision and may thereby be valuable assessment tools.

Background. Perceived muscular tension (PMT) has been suggested to predict development of neck/shoulder pain. It has been hypothesized to be an early sign of musculoskeletal disorder and a possible mediator of stress on symptoms. However, the content of the concept of PMT is not clear. This study examined the association between PMT and physical and psychosocial factors and physical activity in a group of healthy students.

Methods. This cross-sectional study was conducted on the baseline measurements of an ongoing longitudinal case-control study. A total of 63 healthy university students without complaints of neck/shoulder pain were included (21 males, 42 females, mean age 24 years). PMT was measured by asking the question “Have you, during the past month, experienced muscular tension (for example, wrinkled your forehead, ground your teeth, raised your shoulders)?” with the following response options: never, a few times, a few times per week, or one or several times per day. Self-reports on symptoms in the neck, anxiety, depression, stress, mental health, physical health, sleep and physical activity were collected with questionnaires, as well as by tenderness on palpation of neck muscles and trapezius pressure pain threshold. This produced a total of 15 variables. The relationship between these variables and PMT were analyzed using Spearman’s rank correlation coefficient.

Results. Positive correlations were found between PMT and temporomandibular complaints (rho= .34, p < .001), neck crepitus (rho= .33, p < .001), anxiety (rho= .33, p < .001), depression (rho= .31, p < .05), tenderness on palpation (rho= .25, p < .05). There was a negative correlation between PMT and mental health (rho= -.26, p < .05). Frequent experience of PMT had weak to moderate correlations with frequency of symptoms and higher psychosocial strain, but not with stress. This suggests some covariance between PMT and both physical and psychosocial factors.

We investigated the effects of active versus passive pauses implemented during computer mouse work on muscle oxygenation and EMG of the forearm extensor carpi radialis muscle, and on wrist position sense. Fifteen healthy female subjects (age: 19-24 years) performed a 60-min mouse-operated computer task, divided into three 20 min periods, on two occasions separated by 3-6 days. On one occasion a passive pause (subjects resting) was implemented at the end of each 20-min period, and on another occasion an active pause (subjects performed a number of high intensity extensions of the forearm) was implemented. Also at the end of each 20-min period, test contractions were conducted and subjective ratings of fatigue and stress were obtained. Another parameter of interest was total haemoglobin calculated as the summation of oxy-and deoxy-haemoglobin, since it reflects blood volume changes. The most interesting findings were an overall increasing trend in total haemoglobin throughout the mouse work (P<0.001), and that this trend was greater for the active pause as compared to the passive pause (P<0.01). These data were accompanied by an overall increase in oxygen saturation (P<0.001), with a tendency, albeit not significant, toward a higher increase for the active pause (P=0.13). EMG amplitude and median frequency tended to decrease (P=0.08 and 0.05, respectively) during the mouse work but was not different between pause types. Borg ratings of forearm fatigue showed an overall increase during the activity (P<0.001), but the perceptions of stress did not change. Position sense did not change due to the mouse work for either pause type. While increasing trends were found for both pause types, the present study lends support to the hypothesis of an enhancement in oxygenation and blood volume for computer mouse work implemented with active pauses. However, a presumption of an association between this enhancement and attenuated fatigue during the mouse work was not supported.

Chronic trapezius myalgia was shown to be associated with a reduction in microcirculation (via direct measurements of bloodflow). In line with this, morphological data have indicated disturbances in oxidative metabolism. Therefore, data obtained on the muscle oxygenation status could help provide insight into the pathomechanisms behind work related muscle pain. Near-infrared spectroscopy (NIRS) allows for the noninvasive monitoring of continuous changes in skeletal muscle oxygenation (representing the dynamic balance between oxygen delivery and consumption), and for subsequent determinations of changes in blood volume.

Långvarig värk i nacke-skuldra och ländrygg tillhör de vanligaste orsakerna till sjukskrivning. Bakgrunden till dessa tillstånd är vanligen oklara, vilket gör att kausal behandling inte är aktuell. Senare års forskning visar dock att multimodal rehabilitering ger god effekt och är kostnadseffektiv. Forskningen ger även en god grund för att träning av sensomotorisk funktion kan vara effektiv vid dessa tillstånd.

Chronic neck/shoulder pain constitutes an extensive health problem. The point prevalence has been estimated to be as high as 18% in the general population (Guez et al., 2003). The symptoms usually involve pain and stiffness in the neck/shoulder area as well as impaired neck mobility. A history of neck or head trauma is rather common. Thus, in the population studied by Guez et al. (2003), more than one fourth of the cases had a history of such trauma. Nevertheless, due to a limited knowledge on the underlying pathomechanisms, the source of the symptoms can only rarely be established. This obviously poses a severe problem for efficient treatment and rehabilitation of this patient group.

In order to improve treatment and rehabilitation it is thus important to develop sensitive and specific methods for characterization of patients with chronic neck/shoulder pain. This should obviously entail many different aspects of the patient characteristics. One such aspect that has received increasing attention is sensorimotor functions, for example muscle coordination and proprioception. The growing interest in this area is based on an increasing number of studies reporting atypical, or impaired, sensorimotor functioning in subjects with chronic neck/shoulder pain, along with the fact that several models on the pathophysiology behind musculoskeletal disorders involves various aspects of sensorimotor functioning.

This chapter will deal with one of these sensorimotor functions: proprioception. First, a background to the topic and a review on the research on proprioception in relation to chronic neck/shoulder pain is given, along with a discussion on methodology. Lastly, implications for future research as well as clinical implications are discussed.

Bakgrund och syfte

Många yrkesprogram på gymnasiet utbildar för yrken där vi vet att anställda ofta drabbas av belastningsrelaterad ohälsa. Exempelvis visar data från Arbetsmiljöverket att 9–12% av alla installationselektriker och elmontörer rapporterar besvär orsakade av påfrestande arbetsställningar och att de rapporterar en ettårsprevalens på 6–10% för besvär i nacke, axlar, arm och rygg till följd av arbetet som varit så svåra att det påverkat arbetsförmågan. Forskning har även visat att elever på elteknikprogram löper särskilt hög risk att drabbas av arbetsskada relativt andra utbildningar. Redan under utbildningen bör åtgärder sättas in för att minska dessa risker.

En genomgång av litteraturen visar dock att det finns tydliga brister i hur yrkesprogram förbereder eleverna för ett kommande arbetsliv vad gäller arbetsmiljökunskap och att orsakerna till dessa brister troligen finns inom undervisningens innehåll och utformning, lärares kompetens och samverkan med yrkeslivet under utbildningen. Vidare kan elever-nas attityder till arbetsmiljöundervisning utgöra ett hinder. Sammantaget förefaller hin-dren för en bra arbetsmiljöutbildning på yrkesprogram inom gymnasiet vara komplexa och multifaktoriella.

Innan åtgärder sätts in för att utveckla undervisningen finns därför stort behov av att kartlägga de komplexa orsakssambanden bakom brister inom utbildningen och utifrån det utforma förbättringsåtgärder.

I vår studie avser vi att svara på forskningsfrågan: Hur anser olika intressenter att olika faktorer inom såväl utbildningen som framtida yrkeskontext interagerar och bidrar till uppkomsten av belastningsbesvär hos installationselektriker?

Metod och resultat

Studien har en fallstudiedesign där fokusgrupper och problemträdsanalys används. Pro-blemträdsanalys är en metod för att kartlägga komplexa orsakssamband och att klargöra grundläggande orsaker. Analysen kan därmed säkra att aktiviteter och insatser inte väljs och påbörjas utan att man först har kartlagt kärnproblemets ofta komplexa orsaker grundligt.

Som underlag till problemträdsanalysen kommer fokusgruppsintervjuer att genomföras där personer från samma kategori intressenter separat samtalar om kärnproblemet. Vi kommer genomföra intervjuer separat med elever, lärare, skolledning och representanter från arbetslivet. Problemträdsanalysen genomförs sedan vid ett tillfälle där 2–3 personer från varje intressent; elever, lärare, skolledningen, representanter från arbetslivet och forskare från projektgruppen deltar. Inför sessionen kommer vi att delge deltagarna underlag baserat på resultaten från fokusgruppintervjuerna och vår litteratursökning så att de kan ta del avSession D:2Individuella presentationer: Fysiskt arbetsliv93vad andra intressegrupper/källor identifierat som möjliga orsaksfaktorer. Efter framtagande av problemträd kommer tänkbara lösningar att formuleras i samverkan med alla intressenter för att skapa ett lösningsträd, vilket kommer att utgöra grund för kommande utvecklingsarbete inom utbildningen.

Datainsamling och analyser genomförs under våren 2018 och preliminära resultat kommer att presenteras på konferensen.

In order to plan and control movements the central nervous system (CNS) needs to continuously keep track of the state of the musculoskeletal system. Therefore the CNS constantly uses sensory input from mechanoreceptors in muscles, joints and skin to update information about body configuration on different levels of the CNS. On the conscious level, such representations constitute proprioception. Different tests for assessment of proprioceptive acuity have been described. However, it is unclear if the proprioceptive acuity measurements in these tests correlate within subjects. By using both uni- and multivariate analysis we compared proprioceptive acuity in different variants of ipsilateral active and passive limb position-matching and ipsilateral passive limb movement velocity-discrimination in a group of healthy subjects. The analysis of the position-matching data revealed a higher acuity of matching for active movements in comparison to passive ones. The acuity of matching was negatively correlated to movement extent. There was a lack of correlation between proprioceptive acuity measurements in position-matching and velocity-discrimination.

Nackbesvär är vanligt förekommande och utgör en betydande orsak till ohälsa och inskränkt arbetsförmåga. Vanligen går det inte att klarlägga organisk orsak till långvariga nackbesvär men mycket tyder på att de oftast är ett komplext tillstånd där både biologiska och psykosociala faktorer är av betydelse. Forskning har visat på samband mellan långvariga nackbesvär och störningar i olika sensomotoriska funktioner och att graden av funktionspåverkan ofta är kopplad till graden av upplevda besvär. Undersökning av sensomotorisk funktion kan därför vara en viktig del i bedömningen av denna patientgrupp. Forskning har även visat att det finns evidens för positiva effekter av sensomotorisk träning vid nackbesvär på kort sikt, medan kunskap om långtidseffekter saknas. Vid träning av sensomotorisk funktion är det viktigt att beakta grundläggande kunskap inom motorisk inlärning för att öka möjligheterna till bestående träningseffekter och att dessa överförs till vardagliga situationer.

The central nervous system processes sensory input from proprioceptors to form a state estimate of body configuration, which represents proprioception on theconscious level. Proprioception can be divided in two submodalities: sense of movement and sense of position. It is unclear whether tests, involving psychophysical methods and assessing proprioceptive acuity, can separate between perception of movement and position and thus, measure specific proprioception submodalities. In order to investigate if position matching and velocity discrimination tests can separate perception of position and perception of movement, correlations between outcomes of these tests were analyzed. Sixteen young healthy right-handed and gender balanced subjects performed movements in the right glenohumeral joint in all tests. In the ipsilateral position matching test subjects replicated an arm location, achieved in a criterion movement. Movements were performed from positions Q, 4Q and 80- degrees to target positions 16, 32, 48 and 64 degrees with respect to the body sagittal plane. Four conditions, different in terms of movement mode to the target position during criterion and replication movement, were used: passive-active, passive-passive, active-active, semipassive-semipassive. In the latter condition subjects slightly resisted the passive movement. In the ipsilateral velocity discrimination test subjects assessed if a latter comparison arm movement was faster or slower than a previous criterion movement. Criterion movements were performed at velocities of 3Q and 5Q deg/s. T wo conditions were used: passive-passive and semipassive-semipassive. Variable errors (VE) andjust noticeable differences (JND) were measures of proprioceptive acuity in the position matching and velocity discrimination, respectively. Hierarchical cluster analysis (H CA) and principal component analysis (PCA) were applied to study correlations between outcomes in conditions of both tests. In the H CA solution, the position matchi ng and velocity discrimination conditions were located in clusters on opposite poles of the cluster structure. The PCA results were interpreted for six significant components. The position matching and velocity discrimination conditions loaded mainly on components one to five and on component six, respectively. Both the H CA and the PCA separated all test conditions in t wo groups: one contained the position matching and another the velocity discrimination conditions. There were no clear differences between conditions within each group. The study showed that the outcomes VE and JND of the position matching and velocity discrimination, respectively, are mainly uncorrelated. This implies that these tests likely measure different proprioceptive perceptual components or their different combinations. The position matching and velocity discrimination tests could in general separate between perception of position and movement, although no direct evidence was obtained for ex act match of each test with specific proprioception submodality. Much clearer separation of the measured outcomes could be achieved in subjects, heterogeneous with respect to proprioceptive acuity, i.e. with larger variability of performance.

The structure of joint angle variability and its changes with practice were investigated using the uncontrolled manifold (UCM) computational approach. Subjects performed fast and accurate bimanual pointing movements in 3D space, trying to match the tip of a pointer, held in the right hand, with the tip of one of three different targets, held in the left hand during a pre-test, several practice sessions and a post-test. The prediction of the UCM approach about the structuring of joint angle variance for selective stabilization of important task variables was tested with respect to selective stabilization of time series of the vectorial distance between the pointer and aimed target tips (bimanual control hypothesis) and with respect to selective stabilization of the endpoint trajectory of each arm (unimanual control hypothesis). The components of the total joint angle variance not affecting (V(COMP)) and affecting (V(UN)) the value of a selected task variable were computed for each 10% of the normalized movement time. The ratio of these two components R(V)=V(COMP)/V(UN) served as a quantitative index of selective stabilization. Both the bimanual and unimanual control hypotheses were supported, however the R(V) values for the bimanual hypothesis were significantly higher than those for the unimanual hypothesis applied to the left and right arm both prior to and after practice. This suggests that the CNS stabilizes the relative trajectory of one endpoint with respect to the other more than it stabilizes the trajectories of each of the endpoints in the external space. Practice-associated improvement in both movement speed and accuracy was accompanied by counter-intuitive lack of changes in R(V). Both V(COMP) and V(UN) variance components decreased such that their ratio remained constant prior to and after practice. We conclude that the UCM approach offers a unique and under-explored opportunity to track changes in the organization of multi-effector systems with practice and allows quantitative assessment of the degree of stabilization of selected performance variables.

Much is still unknown concerning the mechanisms underlying the development of chronic muscle pain. The presence and magnitude of inflammatory substances and neurotransmitters in chronic painful conditions is not clear. The aims of the present study were to determine, with the use of microdialysis, the interstitial concentrations and the equilibration times for PGE(2) and glutamate in the trapezius muscles of nine female subjects with chronic muscle pain, and nine pain-free age-matched controls. A microdialysis probe was implanted in the upper part of the trapezius muscle and perfused with Ringer-acetate solution at a flow rate of 0.3 muL/min. Samples were obtained every 30 min, during a 4-h rest period. At equilibration, the mean concentrations (+/-SE) of PGE(2) were 0.71 (+/-0.11) ng/mL for the pain-group and 0.97 (+/-0.35) ng/mL for the controls. For glutamate the mean concentrations for the pain-group were 66.3 (+/-13.3) mumol/L and 60.6 (+/-22.9) mumol/L for the controls. For the pain group and the control group, respectively, equilibration for PGE(2) was reached at 180 and 150 min, and for glutamate at 150 and 120 min. The present study showed no differences between groups in the concentrations of PGE(2) and glutamate in the trapezius muscle. Further, it revealed that when using the slow-flow method, a period of at least 2.0-2.5 h is needed, after probe insertion, to reach steady state for glutamate and PGE(2).

Objective:  This study systematically summarizes biochemical biomarker research in non-traumatic musculoskeletal disorders (MSDs).  Two research questions guided the review:  1) Are there biochemical markers associated with neck and upper extremity MSDs? and, 2) Are there biochemical markers associated with the severity of neck and upper extremity MSDs? 

Methods:  A literature search was conducted in PubMed and SCOPUS.  Eighty-seven studies met primary inclusion criteria.  Following a quality screen, data were extracted from 44 sufficient quality articles.

Results:  Most of the 87 studies were cross-sectional and utilized convenience samples of patients as both cases and controls.  A response rate was explicitly stated in only 11 (13%) studies.  Less than half of the studies controlled for potential confounding through restriction or in the analysis.  Most sufficient quality studies were conducted in older populations (mean age in one or more analysis group > 50 yrs).

In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied.  Evidence suggested that: a) the collagen repair marker TIMP-1 is decreased in fibroproliferative disorders, b) 5-HT (serotonin) is increased in trapezius myalgia, and c) triglycerides are increased in a variety of MSDs.  Only five studies showed an association between a biochemical marker and MSD severity.

Conclusion: While some MSD biomarkers were identified, limitations in the articles examined included possible selection bias, confounding, spectrum effect (potentially heterogeneous biomarker associations in populations according to symptom severity or duration) and insufficient attention to co-morbid conditions. A list of recommendations for future studies is provided.

Besvär ifrån kroppens muskler och leder såsom nack- och ryggbesvär är fortfarande ett stort problem inom arbetslivet. Muskuloskeletal diagnos är den vanligaste orsaken till lång sjukfrånvaro inom privat sektor och näst vanligast inom kommuner och landsting. Orsakerna till dessa besvär kan vara relaterade till exponering både under arbete och på fritid, men även till individfaktorer. Vår forskargrupp har en bred ansats för att fylla kunskapsluckor inom detta område och kommer att presentera resultat från flera forskningsprojekt i symposiet Arbete, individ och nacksmärta.

Långvarigt sittande har blivit alltmer vanligt förekommande i många yrkesgrupper. Långvarigt sittande och låg fysisk aktivitet har också uppmärksammats som ett betydande hälsoproblem i dagens arbetsliv och även som en möjlig riskfaktor för smärta i nacke-skuldra. Men forskningen om betydelsen av långvarigt sittande för smärta i nacke-skuldra är fortfarande begränsad. Likaså är det oklart om huvudets hållning vid sittandet och nackens funktion, exempelvis nackens rörelsefunktion och styrka, har betydelse för besvärsutveckling. Statiskt arbete med nacken i vridna och böjda positioner misstänks vara en riskfaktor för nack-skuldersmärta i yrken såsom tandläkare, men det är oklart varför vissa exponerade individer drabbas medan andra inte får ont. För de med långvarig smärta krävs ofta rehabiliterande åtgärder, och hur väl dessa åtgärder lyckas kan även det vara beroende av individens fysiska och psykosociala arbetsmiljö. Individens arbetsmiljö påverkar således inte bara risken för om man får besvär utan kan också ha betydelse för hur rehabiliteringen av besvären lyckas.

Syftet med detta symposium är att presentera studier från Centrum för belastningsskadeforskning som handlar om nacksmärta i arbetslivet, sammanfatta kunskapsläget inom området och diskutera hur arbetet kan utformas för att bli hållbart och inkluderande. De forskningsexempel som presenteras berör stillasittande och hållning i arbetslivet och dess tänkbara konsekvenser för nacksmärta och hälsa, riskfaktorer för nacksmärta i tandläkaryrket och arbetsmiljöns betydelse för resultatet av rehabilitering vid nacksmärta. Symposiet avslutas med en frågestund och gemensam diskussion.

The present study investigated the effects of time pressure and precision demands during computer mouse work on muscle oxygenation and position sense in the upper extremity. Twenty-four healthy subjects (12 males and 12 females) performed a 45-min standardized mouse operated computer task on two occasions. The task consisted of painting rectangles that were presented on the screen. On one occasion, time pressure and precision demands were imposed (more demanding task, MDT) whereas, on the other occasion, no such restraints were added (less demanding task, LDT). The order of the two task versions was randomized. Tissue oxygen saturation in the trapezius and extensor carpi radialis muscles was recorded throughout, and the position matching ability of the wrist was measured before and after the tasks. In addition, measurements of autonomic nervous system reactivity and subjective ratings of tenseness and physical fatigue were obtained. Performance was measured in terms of the number of rectangles that were painted during the task. During MDT, oxygen saturation in extensor carpi radialis decreased (p<0.05) compared to LDT. These data were paralleled by increased electrodermal activity (p<0.05), skin blood flow (p<0.05), ratings of tenseness and fatigue (p<0.01), and increased performance (p<0.01) during MDT. Females exhibited lower oxygen saturation than males, during rest as well as during the computer tasks (p<0.01). Wrist repositioning error increased following LDT as compared to MDT (p<0.05). In conclusion, computer mouse work under time pressure and precision demands caused a decrease in forearm muscle oxygenation, but did not affect wrist position sense accuracy. We attribute our changes in oxygenation more to increased oxygen consumption as a result of enhanced performance, than to vasoconstriction.

Previous studies performed in jaw muscles of rabbits and rats have demonstrated that sympathetic outflow may affect the activity of muscle spindle afferents (MSAs). The resulting impairment of MSA information has been suggested to be involved in the genesis and spread of chronic muscle pain. The present study was designed to investigate sympathetic influences on muscle spindles in feline trapezius and splenius muscles (TrSp), as these muscles are commonly affected by chronic pain in humans. Experiments were carried out in cats anesthetized with alpha-chloralose. The effect of electrical stimulation (10 Hz for 90 s or 3 Hz for 5 min) of the peripheral stump of the cervical sympathetic nerve (CSN) was investigated on the discharge of TrSp MSAs (units classified as Ia-like and II-like) and on their responses to sinusoidal stretching of these muscles. In some of the experiments, the local microcirculation of the muscles was monitored by laser Doppler flowmetry. In total, 46 MSAs were recorded. Stimulation of the CSN at 10 Hz powerfully depressed the mean discharge rate of the majority of the tested MSAs (73%) and also affected the sensitivity of MSAs to sinusoidal changes of muscle length, which were evaluated in terms of amplitude and phase of the sinusoidal fitting of unitary activity. The amplitude was significantly reduced in Ia-like units and variably affected in II-like units, while in general the phase was affected little and not changed significantly in either group. The discharge of a smaller percentage of tested units was also modulated by 3-Hz CSN stimulation. Blockade of the neuromuscular junctions by pancuronium did not induce any changes in MSA responses to CSN stimulation, showing that these responses were not secondary to changes in extrafusal or fusimotor activity. Further data showed that the sympathetically induced modulation of MSA discharge was not secondary to the concomitant reduction of muscle blood flow induced by the stimulation. Hence, changes in sympathetic outflow can modulate the afferent signals from muscle spindles through an action exerted directly on the spindles, independent of changes in blood flow. It is suggested that such an action may be one of the mechanisms mediating the onset of chronic muscle pain in these muscles in humans.

Responses of gastrocnemius-soleus (G-S) motoneurones to stretches of the homonymous muscles were recorded intracellularly in decerebrate cats before, during and after fatiguing stimulation (FST) of G-S muscles. Ventral roots (VR) L7 and S1 were cut, and FST was applied to VR S1, a single FST session including 4 to 5 repetitions of 12-s periods of regular 40 s(-1) stimulation. Muscle stretches consisted of several phases of slow sinusoidal shortening-lengthening cycles and intermediate constant lengths. The maximal stretch of the muscles was 8.8 mm above the rest length. Effects of FST on excitatory postsynaptic potentials (EPSPs) and spikes evoked by the muscle stretches were studied in 12 motoneurones from ten experiments. Stretch-evoked EPSPs and firing were predominantly suppressed after FST, with the exception of a post-contraction increase of the first EPSP after FST, which was most likely due to after-effects in the activity of muscle spindle afferents. The post-fatigue suppression of EPSPs and spike activity was followed by restoration within 60-100 s. Additional bouts of FST augmented the intensity of post-fatigue suppression of EPSPs, with the spike activity sometimes disappearing completely. FST itself elicited EPSPs at latencies suggesting activation of muscle spindle group Ia afferents via stimulation of beta-fibres. The suppression of the stretch-evoked responses most likely resulted from fatigue-evoked activity of group III and IV muscle afferents. Presynaptic inhibition could be one of the mechanisms involved, but homosynaptic depression in the FST-activated group Ia afferents may also have contributed.

Background: It is recognised that back pain (BP) is a debilitating medical problem in the soldier community, which limits operational readiness as well as work ability. As such, identification of risk factors is a necessity for effective preventive actions, but also regarded as important from a safety perspective. The aim of this prospective cohort study was therefore to identify risk factors for back pain and BP limiting work ability in active duty marines within a 6 and 12-month period. Methods: Demographic characteristics, health-related factors and occupational exposure information, as gathered from questionnaires, as well as clinical test of movement control among 137 Swedish marines were regressed with multivariable logistic regressions, and strength of associations was presented as odds ratio (OR) with 95 % confidence intervals (CI). BP within 6 and 12 months were used as primary outcomes, whereas BP limiting work ability within 6 and 12 months served as secondary outcomes. Results: Previous BP and tall body height (≥1.86 m) emerged as risk factors for back pain within 6 months (OR 2.99, 95 % CI 1.22-7.30; OR 2.81, 95 % CI 1.16- 6.84, respectively), and 12 months (OR 6.75, 95 % CI 2.30-19.80; 2.75, 95 % CI 1.21-6.29, respectively). Previous BP was also identified as risk factor for BP limiting work ability within 12 months (OR 6.64, 95 % CI 1.78-24.78), and tall body height emerged as a risk within both six (OR 4.30, 95 % CI 1.31-14.13) and 12 months (OR 4.55, 95 % CI 1.53-13.57) from baseline. Conclusions: Marines with a history of BP are at risk of further BP episodes, which, thus, emphasise the importance of early BP preventive actions. Tall body height also emerged as an important risk which may reflect that personal equipment and work tasks are not adapted for the tallest marines. While this should be considered when introducing new work equipment, further studies are warranted to clarify the underlying mechanism of this association.

Objectives To estimate the prevalence of self-rated musculoskeletal pain and pain limiting work ability in Swedish Armed Forces (SAF) marines, and to study factors potentially associated with pain limiting work ability for the most prevalent pain regions reported.

Design Population-based, cross-sectional survey.

Participants There were 272 SAF marines from the main marine battalion in Sweden included in the study.

Outcomes Self-assessed musculoskeletal pain and pain limiting the marines' work ability within a 6-month period, as obtained from structured questionnaires. The association of individual, health and work-related factors with musculoskeletal pain limiting work ability was systematically regressed with multiple logistic models, estimating OR and 95% CI.

Results Musculoskeletal pain and pain limiting work ability were most common in the back, at 46% and 20%, and lower extremities at 51% and 29%, respectively. Physical training ≤1 day/week (OR 5.3, 95% CI 1.7 to 16.8); body height ≤1.80 m (OR 5.0, 95% CI 1.6 to 15.1) and ≥1.86 m (OR 4.4, 95% CI 1.4 to 14.1); computer work 1/4 of the working day (OR 3.2, 95% CI 1.0 to 10.0) and ≥1/2 (OR 3.3, 95% CI 1.1 to 10.1) of the working day were independently associated with back pain limiting work ability. None of the studied variables emerged significantly associated with such pain for the lower extremities.

Conclusions Our findings show that musculoskeletal pain and resultant limitations in work ability are common in SAF marines. Low frequency of physical training emerged independently associated with back pain limiting work ability. This suggests that marines performing physical training 1 day per week or less are suitable candidates for further medical evaluation and secondary preventive actions. While also associated, body height and computer work need further exploration as underlying mechanisms for back pain limiting work ability. Further prospective studies are necessary to clarify the direction of causality.

OBJECTIVES: To evaluate the occurrence of low back pain (LBP) and LBP that limits work ability, to identify their potential early risks and to quantify occupational physical activity in Swedish Armed Forces (SwAF) marines during their basic 4 month marine training course.

DESIGN: Prospective observational cohort study with weekly follow-ups.

PARTICIPANTS: Fifty-three SwAF marines entering the training course.

OUTCOMES: Incident of LBP and its related effect on work-ability and associated early risks. Occupational physical activity, as monitored using accelerometers and self-reports.

RESULTS: During the training course, 68% of the marines experienced at least one episode of LBP. This yielded a LBP and LBP limiting work ability incidence rate of 13.5 (95% CI 10.4 to 17.8) and 6.3 (95% CI 4.2 to 10.0) episodes per 1000 person-days, respectively. Previous back pain and shorter body height (≤1.80 m) emerged as independent risks for LBP (HR 2.5, 95% CI 1.4 to 4.3; HR 2.0, 95% CI 1.2 to 3.3, respectively), as well as for LBP that limited work ability (HR 3.6, 95% CI 1.4 to 8.9; HR 4.5, 95% CI 2.0 to 10.0, respectively). Furthermore, managing fewer than four pull-ups emerged as a risk for LBP (HR 1.9, 95% CI 1.2 to 3.0), while physical training of fewer than three sessions per week emerged as a risk for LBP that limited work ability (HR 3.0, 95% CI 1.2 to 7.4). More than 80% of the work time measured was spent performing low levels of ambulation, however, combat equipment (≥17.5 kg) was carried for more than half of the work time.

CONCLUSIONS: Incidents of LBP are common in SwAF marines' early careers. The link between LBP and previous pain as well as low levels of exercise highlights the need for preventive actions early on in a marine's career. The role of body height on LBP needs further investigation, including its relationship with body-worn equipment, before it can effectively contribute to LBP prevention.

The visual horizontal-vertical illusion (HVI) refers to the tendency to overestimate vertical distances relative to horizontals in both 2-D and 3-D presentations. Although the HVI is evident across a wide range of different stimuli, no general theoretical account fully explains the illusion. Some recent authors have proposed the 'effort' account of HVI, contending that vertical overestimation is mediated by effort assessment of gravitational challenges offered by the stimulus. The theory has been supported by a set of studies showing that the height overestimation of large-scale 3-D objects is inversely related to perceivers' fitness and strength. We explored if the large-scale HVI/strength dependence extends to the evaluation of small-scale 2-D line stimuli, traditionally used in HVI studies. We measured the maximum handgrip strength, and assessed the HVI with a computerised line-adjustment task in thirty-two individuals. Compatible with earlier findings in the context of large-scale 3-D stimuli, a significant negative correlation was found between the strength of the dominant hand and amount of HVI. In addition, the variability of HVI was negatively correlated with maximum grip strength of both hands. The results are discussed with reference to the 'effort' account of HVI.

The effect of neck/shoulder pain on the performance in a hand laterality motor imagery test was studied. Responses to the Cooper and Shepard (1975, Journal of Experimental Psychology: Human Perception and Performance 104 48 ^ 56) hand laterality test were explored in twenty-four individuals with chronic non-specific neck pain and twenty-one subjects with chronic neck pain of traumatic origin (whiplash-associated disorder). Twenty-two controls were also included in the study. Digitalised right- or left-hand stimuli were presented at five different stimulus angles (08, 458 laterally, 908 laterally, 1358 laterally, and 1808). The experimental task was to decide the laterality as fast and accurately as possible. The performance, both reaction time (RT) and accuracy, of the two experimental groups was contrasted with that of the control group. The main results revealed that the subjects afflicted with whiplash injury on the average exhibited a faster response pattern than symptom-free healthy controls. Despite their  usculoskeletal deficits and experience of pain these volunteers also exhibited a preserved speed ^ accuracy tradeoff. Longer duration of time with symptoms of neck pain was, moreover, associated with progressively faster RTs. These results point to perceptual learning and may reflect different stages of adaptation to neck pain.

AIM: Several studies have reported reduced cervical range of motion (ROM) in people with neck pain. Different methodologies have been used, but with a few exception they measure only head-trunk relationship and do not discriminate between upper and lower cervical motion. Recent strategies for treatment of neck pain condition include retraining the function of the deep cervical flexors that act in cranio-cervical movements. Thus objective measures of cervical ROM in flexion-extension that includes determination of cervical level can be valuable for treatment evaluation.

The aim of the present study was to compare cervical flexion and extension, separate for upper and lower cervical levels, between people with chronic neck pain and controls. Also, the association between upper and lower cervical ROM and self rated characteristics was studied.

METHODS: In a cross-sectional study design, 135 subjects (non-traumatic neck pain: n = 102, controls: n = 33) performed three trials of maximum active cervical flexion and extension. Subjects were seated in a chair with belts crossed over the chest. An electromagnetic tracker system was used to register the kinematics to construct a three-segment model including the trunk, cervical spine and head. The angle for the upper cervical level was defined as the angle between the head and the cervical spine segments. The angle for the lower cervical level was defined as the angle between the cervical spine and the trunk segments. Pressure pain thresholds, pain ratings as well as self ratings of functioning and physical activity were assessed.

RESULTS: Total ROM was reduced in the neck pain group for both the lower (controls: mean = 26.5, SD=6.7, neck pain: mean=19.0, SD =6.5 degrees) and the upper cervical levels (controls: mean = 84.7, SD = 7.9, neck pain: mean = 73.0, SD = 11.2 degrees). This reduction was direction specific: in the upper cervical level only extension was reduced and in the lower cervical level the reduction was predominately in flexion. Multivariate regression analysis revealed that lower level of physical activity, greater impairments of physical functioning, self reported problems with head movements and lower pressure pain thresholds were related to a greater reduction in ROM in the neck pain group.

CONCLUSION: Reduction of ROM is present for both the upper and lower levels of the cervical spine in people with non-traumatic neck pain. For the upper cervical level this reduction is direction specific so that only extension is reduced. The limited extension range of the upper cervical spine in the neck pain group could reflect a habituated sitting posture that includes a more extended upper cervical spine. Alternatively it could reflect an impaired functioning of the deep cervical flexors. For the lower cervical level the reduction was mainly limited to flexion. This could be a reflection of a ‘head forward posture’ that has previously been reported in people with neck pain. The associations between self rated characteristics and range of motion variables supports the validity of this methodology in research on neck pain conditions.

Reduced cervical range of motion (ROM) is a common finding in people with neck pain. With few exceptions, only the angle between head and thorax has been measured. Our aim was to use an extended model to compare active cervical flexion and extension, separate for upper and lower cervical levels, between people with chronic non-traumatic neck pain and controls. We also investigated associations between ROM measures, symptoms and self-rated functioning. In this cross-sectional study, 102 subjects with neck pain and 33 healthy controls participated. An electromagnetic tracker system was used to measure the kinematics to construct a three-segment model including the thorax, cervical spine and head. Neutral flexion/extension were defined at subjects’ self-selected seated posture. We found that in the neck pain group, extension in the upper cervical levels and predominately flexion for the lower levels were reduced. The ratio between ROM for the upper and lower levels was altered in the neck pain group so that the lower levels contributed to a lesser extent to the total sagittal ROM compared to controls. These findings could not be explained by a greater forward head posture but must have other origins. For the neck pain group, ROM measures were weakly associated to pain and self-rated functioning. Altogether, this implies that using a three-segment model for assessment of ROM can be a valuable improvement for characterisation of patients and treatment evaluation.

Background: Cervical range of motion (ROM) is commonly assessed in clinical practice and research. In a previous study we decomposed active cervical sagittal ROM into contributions from lower and upper levels of the cervical spine and found level- and direction-specific impairments in women with chronic non-specific neck pain. The present study aimed to validate these results and investigate if the specific impairments can be explained by the neutral posture (defining zero flexion/extension) or a movement strategy to avoid large gravitationally induced torques on the cervical spine.

Methods: Kinematics of the head and thorax was assessed in sitting during maximal sagittal cervical flexion/extension (high torque condition) and maximal protraction (low torque condition) in 120 women with chronic non-specific neck pain and 40 controls. We derived the lower and upper cervical angles, and the head centre of mass (HCM), from a 3-segment kinematic model. Neutral head posture was assessed using a standardized procedure.

Findings: Previous findings of level- and direction-specific impairments in neck pain were confirmed. Neutral head posture was equal between groups and did not explain the direction-specific impairments. The relative magnitude of group difference in HCM migration did not differ between high and low torques conditions, lending no support for our hypothesis that impairments in sagittal ROM are due to torque avoidance behaviour.

Interpretation: The direction- and level-specific impairments in cervical sagittal ROM can be generalised to the population of women with non-specific neck pain. Further research is necessary to clarify if torque avoidance behaviour can explain the impairments.

Objective: To evaluate the effect of neck coordination exercise on sensorimotor function in women with neck pain compared with best-available treatment and sham treatment. Design: Observer-blinded randomized controlled trial with short-term and 6-month follow-ups. Subjects: Women with chronic non-specific neck pain were randomized to 3 groups: neck coordinationexercise with a novel training device; strength training for the neck and shoulders; or massage. Each group had 36 participants. Methods: The intervention period was 11 weeks with 22 individually supervised sessions. Primary outcomes were postural sway measures and precision of goal-directed arm movements. Secondary outcomes were range of motion for the neck, peak speed of axial rotation, and neck pain. A repeated measures multivariate analysis of variance (MANOVA) was conducted separately on the primary outcomes for the short-term and 6-month evaluations and on the sensorimotor secondary outcomes for the 6-month effect. The 6-month effect on pain was analysed with a repeated measures analysis ofvariance (ANOVA). Results: No significant treatment effects in favour of neck coordination exercise were found for short-term or 6-month evaluations. Conclusion: Neck coordination exercise is no better than strength training and massage in improvingsensorimotor function. Further research should investigate the use of cutoffs for sensorimotordysfunctions prior to proprioceptive or coordinative training.