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, η_p² = 0.746). Control of deep and superficial cervical muscles differed (p = 0.003, η_p² = 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.

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.

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.

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.

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.

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.

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.

Background. To improve the care of patients suffering from musculoskeletal disorders (MSD) further knowledge regarding the prevalence, diagnostics and management of different MSD in primary care is required. Thus the aims of this study were: -to investigate the prevalence of patients seeking care due to different MSD at primary health care centres (PHCs); -to chart different factors as symptoms, diagnosis, and actions prescribed for patients that visited the PHCs due to MSD; and -to make comparisons regarding differences due to gender, age, and rural or urban PHC.

Methods. 2000 patient records for patients in working age were randomly selected equally distributed on one rural and one urban PHC. A 3-year period was reviewed retrospectively. For all patient records age, sex, occupation, occupational activity, date of visit, if it was a new or re-visit, cause to the visit, and diagnosis related to the visit were registered. For visits due to MSD the location of the patients symptoms, which symptoms were described in the patient record, the type of those symptoms, which actions were prescribed to resolve the patients problems, and also sickleave prior to and after the visit, were registered. Data was analysed using cross tabulation, multidimensional Chi-square (Pearson), and a probability level of p < .05.

Results. The prevalence of MSD was high, almost 60 % of the patients had some sort of MSD symptoms, either at the day for visit or the reviewed 3 year period, and a bit higher among women than men. Upper and lower limb problems were most common. Symptoms were most prevalent in the young and middle age-groups. The patients got a variety of different diagnoses, and between 13-35 % of the patients did not receive a MSD-diagnose despite having MSD-symptoms. There was a great variation in how the cases were handled. Medication and sick leave certificates were most common while work-related rehabilitation was less common. Conclusion. The present study points out some weaknesses regarding diagnostics and management of MSD in primary care. Further studies to compare the results regarding diagnoses for musculoskeletal symptoms and measures taken to solve the patients’ problems would be of interest.

BACKGROUND:

The evidence for the effect of treatments of neck pain is modest. In the absence of causal treatments, a possibility is to tailor the treatment to the individuals' functional limitations and symptoms. The aim was to evaluate treatment effects of a tailored treatment versus a non-tailored treatment. Our hypothesis was that tailored treatment (TT) would have better effect on pain intensity and disability than either non-tailored treatment (NTT) (same treatment components but applied quasi-randomly) or treatment-as-usual (TAU) (no treatment from the study, no restrictions). We further hypothesized that TT and NTT would both have better effect than TAU.

METHOD:

One hundred twenty working women with subacute and chronic non-specific neck pain were allocated to 11 weeks of either TT, NTT or TAU in a randomized controlled trial with follow-ups at 3, 9 and 15 months. The TT was designed from a decision model based on assessment of function and symptoms with defined cut-off levels for the following categories: reduced cervical mobility, impaired neck-shoulder strength and motor control, impaired eye-head-neck control, trapezius myalgia and cervicogenic headache. Primary outcomes were pain and disability. Secondary outcomes were symptoms, general improvement, work productivity, and pressure pain threshold of m. trapezius.

RESULTS:

Linear mixed models analysis showed no differences between TT and NTT besides work productivity favoring TT at 9- and 15-months follow-ups. TT and NTT improved significantly more than TAU on pain, disability and symptoms at 3-month follow-up. General improvement also favored TT and NTT over TAU at all follow-ups.

CONCLUSION:

Tailored treatment according to our proposed decision model was not more effective than non-tailored treatment in women with subacute and chronic neck pain. Both tailored and non-tailored treatments had better short-term effects than treatment-as-usual, supporting active and specific exercise therapy, although therapist-patient interaction was not controlled for. Better understanding of the importance of functional impairments for pain and disability, in combination with a more precise tailoring of specific treatment components, is needed to progress.