Accumulation of psychosocial and lifestyle factors and risk of low back pain in adolescence: a cohort study.

PURPOSE: Low back pain (LBP) is common already in adolescence, and many risk indicators including both psychosocial and lifestyle factors have been recognized. Our purpose was to assess whether the co-occurrence of psychosocial (externalizing and internalizing) problems and lifestyle factors (leisure time physical activity, sedentary behaviour, sleep, smoking, and overweight/obesity) associate with LBP at 16 years cross-sectionally or with new LBP at 18-year follow-up. METHODS: The study population, drawn from the Northern Finland Birth Cohort 1986, consisted of 1625 participants (712 boys and 913 girls) who completed a questionnaire on potential explanatory factors at 16 years and on LBP at 16 and 18 years. The outcome measure was 'reporting LBP' or 'consultation for LBP' during the past 6 months. Latent Class Analysis (LCA) was utilized to study the co-occurrence of the explanatory factors. RESULTS: Among both genders, four clusters were found. Externalizing behaviour problems were associated with 'reporting LBP' (RR 1.5, boys 1.4, girls) and 'consultation for LBP' (RR 1.6 for both genders) at baseline among both genders. In addition, the cluster of multiple risk behaviours was associated with both 'reporting LBP' (RR 1.3) and 'consultation for LBP' (RR 2.5) and the obese cluster with 'consultation for LBP' (RR 1.7) among girls. Externalizing behaviour problems at 16 years predicted 'consultation for LBP' at 18 years among girls (RR 3.6). CONCLUSIONS: Our results stress the role of psychosocial factors in reporting and seeking care for adolescent LBP.

Association between overweight and low back pain: a population-based prospective cohort study of adolescents.

STUDY DESIGN: A prospective cohort study in adolescents aged 7 to 19 years. OBJECTIVE: To evaluate whether persistent overweight increases the risk of low back pain (LBP) among adolescents. SUMMARY OF BACKGROUND DATA: Overweight and LBP are common health problems in adolescents. Their relationship is still controversial among adolescents, as well as among adults. METHODS: The study population, the Oulu Back Study, was drawn from the Northern Finland Birth Cohort 1986. The final study sample included 1660 adolescents (56% females). The subcohort of 786 subjects (57% females) was used in the analysis of waist circumference. The association between the area under the curve of body mass index from 7 to 16 years, and from 16 to 18 years, and area under the curve of waist circumference from 16 to 19 years, and LBP during the past 6 months was evaluated separately for incident (reporting LBP at 18 or 19 yr but not at 16 yr) and persistent LBP (reporting LBP at 16 and 18 yr or 19 yr). Relative risks (RR) and their 95% confidence intervals (95% CI) were adjusted for smoking, leisure time physical activity, and family socioeconomic status at 16 years and stratified by sex. RESULTS: Body mass index from 16 to 18 years among girls and body mass index from 7 to 16 years among boys predicted incident LBP at 18 years (girls: RR, 1.09; 95% CI, 1.01-1.18; boys: RR, 1.15; 95% CI, 1.00-1.32). Among boys, waist circumference from 16 to 19 years was also associated with incident LBP (RR, 1.16; 95% CI, 1.02-1.32). Overweight was not associated with persistent LBP. CONCLUSION: In this population-based cohort study, persistent overweight slightly increased the risk of incident LBP, but the time period during which overweight was related to incident LBP differed between sexes. LEVEL OF EVIDENCE: 2.

Physical workload and risk of low back pain in adolescence.

OBJECTIVES: To evaluate the role of physical workload in low back pain (LBP) among adolescents. METHODS: Working history and physical workload factors at 18 years were assessed for 1984 members of the Northern Finland Birth Cohort 1986. The associations between work characteristics and LBP were analysed by multinomial logistic regression. Those with and without LBP at 18 years of age were compared in two subsamples. The incidence of LBP was studied among the 986 subjects without LBP at 16 years of age. Persistence of LBP was studied among the 728 subjects with LBP at 16 years of age. Latent class analysis (LCA) was used to form natural clusters of workload factors and their associations with LBP were investigated using log-binomial regression. RESULTS: 753 (75%) subjects without LBP at 16 years of age had been working during the 2-year follow-up period. The average duration of work was 6.2 months. In adolescent girls, working regularly or irregularly and duration of work exposure were associated with incident LBP. Of specific physical workload factors, only awkward trunk postures were associated with incident LBP in both genders (RR 1.2 in girls and 1.7 in boys). The work exposure patterns in adolescent girls and boys were different. In the LCA, subjects in a cluster with high exposure to awkward trunk postures or an overall physically demanding job had a higher likelihood of incident LBP in both genders (RR 1.3-1.9). None of the specific workload factors or clusters was associated with persistent LBP. CONCLUSIONS: Physical workload factors constitute a risk for LBP even in adolescents.

Multidisciplinary rehabilitation after primary total knee arthroplasty: a randomized controlled study of its effects on functional capacity and quality of life.

OBJECTIVE: To examine whether a multidisciplinary rehabilitation programme can improve functional recovery and quality of life and reduce the use of rehabilitation services compared with conventional care one year after total knee arthroplasty. DESIGN: Prospective, randomized, non-blinded, controlled trial. SETTING: An outpatient centre-based setting. SUBJECTS: Eighty-six patients who were scheduled for primary total knee arthroplasty due to osteoarthritis of the knee. INTERVENTIONS: A ten-day multidisciplinary rehabilitation programme, which was focused on enhancing functional capacity, was organized 2-4 months after surgery. In both groups, a standard amount of physiotherapy was included in conventional care. MAIN MEASURES: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the 15D, 15-m walk test, stair test, isometric strength measurement of the knee. Use of rehabilitation services was asked about with a questionnaire. Outcomes were assessed preoperatively and at 2-, 6- and 12-month follow-ups. RESULTS: In both groups, functional capacity and quality of life improved significantly. The mean absolute change in the WOMAC function score was -32.4 mm (SD 26.4) in the rehabilitation group and -32.8 mm (SD 20.1) in the control group (P-time*group = 0.40). No difference was found between groups in any outcome measure or in the use of rehabilitation services during the study period. CONCLUSIONS: This study indicates that for knee osteoarthritis patients treated with primary total knee arthroplasty, a 10-day multidisciplinary outpatient rehabilitation programme 2-4 months after surgery does not yield faster attainment of functional recovery or improvement in quality of life than can be achieved with conventional care.

Disability in end-stage knee osteoarthritis.

OBJECTIVE: To examine the attributes of disability in end-stage knee osteoarthritis (OA) by analyzing the relationships between self-reported disability and objectively measured physical function after controlling pain, personal characteristic factors, and pathophysiological factors. METHODS: The present study adopted a cross-sectional design. The subjects (n=88, aged 60-80 years) were scheduled for primary unilateral total knee arthroplasty (TKA) due to knee OA. Self-reported disability and pain were measured with the Western Ontario and McMaster Universities OA Index (WOMAC) and the RAND 36-item Health Survey 1.0 (RAND-36). Physical performance tests included a 15-m walk test and stair performance. Knee isometric muscle strength was measured. A clinical examination included analyses of comorbidity, body mass index (BMI), and a detailed knee examination: The flexion range of motion (ROM) was measured; the presence of varus/valgus malalignments and antero-posterior laxity was assessed. Radiographs were analyzed with the Kellgren-Lawrence grading scale. RESULTS: In the linear regression model the WOMAC pain score, antero-posterior laxity of the knee, age, and BMI accounted for 54.8% of the variance in the WOMAC function score. In the bivariate analyses the WOMAC function score had a positive correlation with the 15-m walk (r(s)=0.32, p=0.003), stairs up (r(s)=0.40, p=0.001), and stairs down (r(s)=0.38, p=0.001) tests, and a negative correlation with RPT extension (r(s)=-0.45, p < 0.001) and RPT flexion (r(s)=-0.39, p=0.001) of the affected side and RPT flexion (r(s)=-0.39, p <0.001) of the contralateral side. The results of the physical performance tests also correlated with the RAND-36 Physical function (PF) score. Comorbid diseases and pain deteriorated the results of the physical performance tests and self-reported disability. Female gender deteriorated the results of the physical performance tests and the RAND-36 PF, but not the WOMAC function score. Malalignments, restriction in the flexion ROM of the knee, and the radiologic severity of knee OA did not affect self-reported disability. CONCLUSION: Pain, BMI, and antero-posterior laxity of the knee joint were major attributes of self-reported disability. The negative effect of comorbid diseases and female gender on health-related quality of life was significant. The results of objectively measured physical performance tests correlated with self-reported disability.

Is smoking a risk factor for low back pain in adolescents? A prospective cohort study.

STUDY DESIGN: A prospective cohort study in adolescents. OBJECTIVE: To evaluate whether smoking in adolescence is a risk factor of low back pain (LBP) among young adults. SUMMARY OF BACKGROUND DATA: Smoking has been found to associate with LBP among adults. Longitudinal studies performed in adolescents are few. METHODS: The children belonging to the northern Finland Birth Cohort 1986 were examined at birth and at 16 years of age and followed up by a postal questionnaire at the age of approximately 18 years. The primary outcome was LBP during the past 6-month period. Incident cases reported LBP at 18 but not at 16 years. Persistent cases reported pain at both time points. Logistic regression analysis was used to evaluate the effect of smoking exposure on any LBP in both genders separately and multinomial regression analysis was used to evaluate the effect on the severity of LBP (No LBP, "Reporting LBP," "Consultation for LBP") in the total population. Parents' socioeconomic status, physical activity, body mass index, and depressive mood were used as confounders in the analyses. RESULTS: Regular smoking at 16 years was associated with persistent LBP in girls (OR: 2.52; 95% CI: 1.40-4.53). Daily smoking of over 9 cigarettes at 16 was associated with persistent LBP (2.57; 1.03-6.46) and predicted incident pain in girls (2.80; 1.11-7.09). Pack-years of smoking were associated with incident and persistent LBP in the girls with an exposure-response relationship, whereas these associations were inconsistent in the boys. Pack-years of smoking at 18 years showed an exposure-response relationship with persistent Consultation for LBP, which was strongest in those with over 1.5 pack-years of exposure (5.82; 1.39-24.42). CONCLUSION: Regular smoking in adolescence was associated with LBP in young adults. Pack-years of smoking showed an exposure-response relationship among girls.

Chronic Chlamydia pneumoniae infection increases the risk of occlusion of lumbar segmental arteries of patients with sciatica: a 3-year follow-up study.

STUDY DESIGN: A magnetic resonance imaging follow-up study of lumbar arteries among patients with sciatica with chronic Chlamydia pneumoniae infection. OBJECTIVE: To determine whether chronic infection causes occlusion of lumbar arteries. SUMMARY OF BACKGROUND DATA: C. pneumoniae infection is associated with coronary heart disease, and the infectious pathogen has also been detected in abdominal aortic aneurysms and in atherosclerotic plaques. No studies are available on the effect of this infectious agent on lumbar arteries. METHODS: Chronic infection was defined as persistent high positive immunoglobulin G and/or immunoglobulin A antibodies and/or the presence of immune complexes. The lumbar arteries, evaluated with two-dimensional time-of-flight magnetic resonance angiography, were scored as normal, narrowed, or occluded. The differences in the segmental and whole lumbar spine (segments L1-L4) sum of arterial occlusion at baseline and at 3 years, and the incidence of new arterial stenosis were compared in patients with and without chronic infection using the Kolmogorov-Smirnov test. RESULTS: Patients with chronic infection were more likely to be persistent smokers (P = 0.006), male (P = 0.04), and more obese (P = 0.02) compared to patients with normal antibody levels. They had significantly higher degree of arterial stenosis at L4 segment at baseline and at 3 years (P = 0.001 and 0.002, respectively), in the whole lumbar spine at baseline and at 3 years (P < 0.001 for both), and at L1 and L3 segments at 3 years (P = 0.013 for both). The incidence of new arterial stenosis was similar in both patient groups. Patients with chronic infection also had significantly higher grade of endplate degeneration at L4-L5 (P = 0.008). CONCLUSIONS: The results of this study suggest that chronic C. pneumoniae infection may induce stenosis of lumbar arteries.