Background The aim of this study was to test whether a reciprocal dose-response relation exists between frequency/severity of spinal pain and temporomandibular disorders (TMD). Methods A total of 616 subjects with varying severity of spinal pain or no spinal pain completed a questionnaire focusing on symptoms in the jaw, head and spinal region. A subset of the population (n = 266) were sampled regardless of presence or absence of spinal pain. We used two different designs, one with frequency/severity of spinal pain, and the other, with frequency/severity of TMD symptoms as independent variable. All 616 participants were allocated to four groups, one control group without spinal pain and three spinal pain groups. The subjects in the subset were allocated to one control group without TMD symptoms and three TMD groups. Odds ratios (ORs) were calculated for presence of frequent TMD symptoms in the separate spinal pain groups as well as for frequent spinal pain in the separate TMD groups. Results The analysis showed increasing ORs for TMD with increasing frequency/severity of spinal pain. We also found increasing ORs for spinal pain with increasing frequency/severity of TMD symptoms. Conclusion This study shows a reciprocal dose-response-like relationship between spinal pain and TMD. The results indicate that these two conditions may share common risk factors or that they may influence each other. Studies on the temporal sequence between spinal pain and TMD are warranted.

Many children with cerebral palsy (CP), especially non-walkers, were previously reported to have cold extremities, pain, sleeping disorders, constipation, and impaired well-being – besides accompanying impairments. Most children had had one or more of these symptoms for more than 1 year, and the symptoms were largely untreated. This study (1) describes mood, health, and daily life experiences of the children's parents; (2) explains impact that the child's impairments and symptoms have on the family; and (3) investigates community services support. Information in this study was gathered from parents of 106 children, ages 5–16, with CP, who lived in northern Sweden. Compared with parents of walkers, parents with non-walking children and several disorders were more frequently anxious for their children's physical and psychological health; often experienced restricted time for themselves; reported frequent daily living interferences; and stated that their health was affected due to the child's health. 10 percent of all families reported that their need of community services support was unmet. To improve health and to provide good community services support for the entire family, regular follow-up and evaluation of the child's treatment and family support are important.

Abstract Vrijheid, M., Cardis, E., Ashmore, P., Auvinen, A., Gilbert, E., Habib, R. R., Malker, H., Muirhead, C. R., Richardson, D. B., Rogel, A., Schubauer-Berigan, M., Tardy, H. and Telle-Lamberton, M., for the 15-Country Study Group. Ionizing Radiation and Risk of Chronic Lymphocytic Leukemia in the 15-Country Study of Nuclear Industry Workers. Radiat. Res. 170, 661–665 (2008). In contrast to other types of leukemia, chronic lymphocytic leukemia (CLL) has long been regarded as non-radiogenic, i.e. not caused by ionizing radiation. However, the justification for this view has been challenged. We therefore report on the relationship between CLL mortality and external ionizing radiation dose within the 15-country nuclear workers cohort study. The analyses included, in seven countries with CLL deaths, a total of 295,963 workers with more than 4.5 million person-years of follow-up and an average cumulative bone marrow dose of 15 mSv; there were 65 CLL deaths in this cohort. The relative risk (RR) at an occupational dose of 100 mSv compared to 0 mSv was 0.84 (95% CI 0.39, 1.48) under the assumption of a 10-year exposure lag. Analyses of longer lag periods showed little variation in the RR, but they included very small numbers of cases with relatively high doses. In conclusion, the largest nuclear workers cohort study to date finds little evidence for an association between low doses of external ionizing radiation and CLL mortality. This study had little power due to low doses, short follow-up periods, and uncertainties in CLL ascertainment from death certificates; an extended follow-up of the cohorts is merited and would ideally include incident cancer cases.

Cold extremities have been noted in non-walking children with cerebral damage compared with healthy controls. Whether this is a general problem in children with cerebral palsy (CP) and associated with other symptoms is unknown. This study describes accompanying symptoms such as cold extremities, constipation, pain, sleeping disorders and impaired well-being in children with CP as well as treatment the children have undergone. Associations between cold extremities and other symptoms borne by the children were analysed and discussed. From information in postal surveys received from parents of children with CP, 107 children (60 boys and 47 girls) aged 5–13 years, mean 11 years 8 months (SD 2 years 11 months), were described and analysed. Besides neurological impairments, many children had cold extremities and pain, sleeping disorders, constipation, and impaired well-being. Most children had had one or more of these symptoms for over 1 year but the symptoms were largely untreated. Non-walkers generally had more symptoms than walkers. Although pain, constipation, and sleeping disorders may have different underlying causes in children with CP, these symptoms might also be mediated or aggravated by dysfunction in the autonomic nervous system. To improve the child's well-being, early recognition and treatment of accompanying symptoms is important.

Back pain and temporomandibular disorders are both common conditions in the population with influence on the human motor system, but a possible co-morbidity between these conditions has not been fully investigated. The aim of this study was to test the hypothesis of an association between long-term back pain and pain and/or dysfunction in the jaw-face region. Back pain was defined as pain in the neck, shoulders and/or low back. The study-population comprised 96 cases with long-term back pain and 192 controls without back pain. We used a screening procedure, a questionnaire and a clinical examination of the jaw function. The questionnaire focused on location, frequency, duration, intensity and impact on daily life of symptoms in the jaw-face and back regions. The analysis was conducted on 16 strata, matched by age and sex for case vs. control, using Mantel-Haenszel estimates of matched odds ratio (OR) and 95% confidence interval (CI) as well as the corrected Mantel-Haenszel chi(2) test. The overall prevalence of frequent symptoms in the jaw-face region, as reported in the questionnaire, was 47% among cases and 12% among controls. The difference was statistically significant (P<0.0001) with a sevenfold odds ratio (CI: 3.9-13.7). Moderate to severe signs from the jaw region were clinically registered among 49% of the cases and 17% of the controls (P<0.0001, OR: 5.2, CI: 2.9-9.2). The results showed statistically significant associations between long-term back pain and musculoskeletal disorders in the jaw-face and indicate co-morbidity between these two conditions.

This study investigated how ergonomic design influences neck-and-shoulder muscle strain, through keyboard assessment. Muscular activity was measured electromyographically (EMG) from six muscles in the forearm and shoulders of eight experienced typists using each of five different types of keyboard: one mechanical, one electromechanical, and one electronic typewriter; one personal computer/word processor (PC-XT) keyboard; and one angled at 20 degrees in the horizontal plane. The impact on muscular activity of using a palmrest was also studied. The mechanical typewriter induced a higher strain in the forearm and finger muscles than did the modern typewriters and keyboards. These induced no different strain on the neck-and-shoulder muscles, except for the right shoulder muscle, which was more active with the electronic typewriter than with the other machines. Using a palmrest did not decrease the strain on the muscles investigated. Use of the 'angled' PC-XT keyboard did not influence the measured muscular load on the forearm and finger muscles compared to typing on an ordinary PC-XT keyboard, but decreased the extensor muscular strain compared to the electronic typewriter.