title: The Association Between Physical Workload and Low Back Pain Clouded by the “Healthy Worker” Effect: Population-Based Cross-Sectional and 5-Year Prospective Questionnaire Study Physical and Mental Function and Incident Low Back Pain in Seniors: A Population-Based Two-Year Prospective Study of 1387 Danish Twins Aged 70 to 100 Years The Effects of a Graded Activity Intervention for Low Back Pain in Occupational Health on Sick Leave, Functional Status and Pain: 12-Month Results of a Randomized Controlled Trial TTM-based motivational counselling does not increase physical activity of low back pain patients in a primary care setting--A cluster-randomized controlled trial. Low Back Pain in a General Population. Natural Course and Influence of Physical Exercise–A 5-Year Follow-up of the Musculoskeletal Intervention Center-Norrtälje Study Do Patients With Chronic Low Back Pain Have a Lower Level of Aerobic Fitness Than Healthy Controls?: Are Pain, Disability, Fear of Injury, Working Status, or Level of Leisure Time Activity Associated With the Difference in Aerobic Fitness Level? The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. Effectiveness of a home exercise programme in low back pain: a randomized five-year follow-up study. Deconditioning in Patients With Chronic Low Back Pain: Fact or Fiction? The effectiveness of graded activity for low back pain in occupational healthcare Validity and repeatability of a modified Baecke questionnaire on physical activity. Predictors of return to work in patients sick listed for sub-acute low back pain: a 12-month follow-up study. Effects of recreational physical activity and back exercises on low back pain and psychological distress: findings from the UCLA Low Back Pain Study. Hierarchy of evidence: where observational studies fit in and why we need them. Fear-avoidance Beliefs, Physical Activity, and Disability in Elderly Individuals With Chronic Low Back Pain and Healthy Controls
abstract: Study Design . A population -based cross-sectional and 5-year prospect i ve question naire study . Objective . To investigate self-reported physical workload as a risk factor for low back pain . Summary of Background Data . Both physical and psychosocial workplace factors are considered risk factors for low back pain . However , today no consensus has been reached regarding the exact role of these factors in the genesis of low back pain . Methods . Question naire data were collected at baseline for 1397 ( and after 5 years for 1163 ) men and women aged 31–50 years at baseline .  Low back pain ( “ any low back pain within the past year , ” “ low back pain ≤ 30 days in total during the past year , ” “ low back pain > 30 days in total during the past year ” ) was analyzed in relation to physical workload ( sedentary , light physical , and heavy physical work ) using logistic regression and controlling for age , gender , and social group . The proportions of workers changing between the workload groups over the 5-year period were analyzed in relation to low back pain status . Results . At baseline no statistically significant differences in low back pain outcomes were found for workers exposed to sedentary , light physical , or heavy physical work . This was true for all age , gender , and social groups . At follow-up there was a statistically significant dose – response association between any low back pain and longst and ing low back pain within the past year and increasing physical workload  at baseline also after controlling for age , gender , and social group . Subjects with heavy physical workload at baseline changed statistically significantly more often to sedentary work if they experienced low back pain for more than 30 days out of the past year . Conclusions . Having a sedentary job might have a protective or neutral effect in relation to low back pain , whereas having a heavy physical job constitutes a significant risk factor . Because of migration between exposure groups ( the “ healthy-worker ” effect ) , longitudinal studies are necessary for investigating the associations between physical workload and low back pain Study Design . Prospect i ve cohort study . Objectives . To investigate whether physical performance , grip strength , cognitive function , and depression symptomatology are risk factors for incident low back pain ( LBP ) over a 2-year period in seniors . Summary of Background Data . LBP is common in the older age groups , but little is known about predictors of LBP in this age group . Methods . Data from the 2001 and 2003 data collection from the population -based Longitudinal Study of Aging Danish Twins formed the basis of this analysis . Participants free from LBP at baseline ( no LBP during the past month , N = 1387 ) were included and interview data on overall physical function , and assessment of grip strength , overall cognitive function , and depression at baseline were obtained . LBP status at follow-up was assessed using a modified version of the St and ardized Nordic Question naire . Logistic regression was used to assess the associations between the baseline risk factors and LBP at follow-up . Results . A total of 1387 persons 70 to 100 years of age at baseline were included in the analyses . Of the initially LBP-free individuals , 7 % had experienced LBP more than 30 days out of the past year , 7 % had altered or decreased their physical activities due to LBP , and 11 % had received treatment for LBP at follow-up . Good overall physical function ( being among the top 50 % ) at baseline was protective for LBP of more than 30 days duration and for diminishing physical activities due to LBP and for care seeking due to LBP . High depression scores ( being among the top 25 % ) were strongly associated with altering or decreasing daily activities because of LBP . Grip strength and overall cognitive performance at baseline were associated with lower incidence of LBP and decreasing activities due to LBP at follow-up ; however , these associations were not statistically significant . Conclusion . Poor overall physical function and depression symptomatology are associated with LBP and consequences of LBP in persons 70 years of age and older Introduction : Behaviorally oriented grade d activity interventions have been suggested for sick-listed workers with low back pain on return to work , but have not been extensively evaluated . Methods : One hundred and thirty-four workers were r and omly assigned to either a grade d activity intervention ( n = 67 ) or usual care ( n = 67 ) and followed-up for 12 months . Results : The grade d activity group returned back to work faster with a median of 54 days compared to 67 days in the usual care group . The grade d activity intervention was more effective after approximately 50 days post-r and omization ( HRR = 1.9 , CI = 1.2–3.1 , p = 0.01 ) . Differences between the groups in number of recurrent episodes , total number of days of sick leave due to low back pain , and total number of days of sick leave due to all diagnoses , were in favor of the grade d activity group , although not statistically significant . No effects of the grade d activity intervention were found for functional status or pain . Conclusion : Grade d activity intervention is a valuable strategy to enhance short-term return to work outcomes OBJECTIVE To investigate the effectiveness of a TTM-based motivational counselling approach by trained practice nurses to promote physical activity of low back pain patients in a German primary care setting . METHODS Data were collected in a cluster-r and omized controlled trial with three study arms via question naires and patient interviews at baseline and after 6 and 12 months . We analysed total physical activity and self-efficacy by using r and om effect models to allow for clustering . RESULTS A total of 1378 low back pain patients , many with acute symptoms , were included in the study . Nearly 40 % of all patients reported sufficient physical activity at baseline . While there were significant improvements in patients ' physical activity behaviour in all study arms , there was no evidence for an intervention effect . CONCLUSION The outcome may be explained by insufficient performance of the practice nurses , implementation barriers caused by the German health care system and the heterogenous sample . PRACTICE IMPLICATION S Given the objective to incorporate practice nurses into patient education , there is a need for a better basic training of the nurses and for a change towards an organizational structure that facilitates patient-nurse communication . Counselling for low back pain patients has to consider more specificated aims for different subgroups Study Design . A 5-year prospect i ve cohort study was conducted of men and women seeking care for a new period of low back pain ( LBP ) . Objectives . To study the natural course of pain and disability due to LBP during a 5-year follow-up period , and to investigate the possible influence of regular physical exercise on recovery . Summary of Background Data . LBP is major health problem , but its natural course is not very well studied . Several studies have investigated the role of physical exercise on LBP disorders , with inconsistent results . Methods . At baseline , a total of 790 subjects seeking care for LBP were interviewed about physical exercise during leisure time . Over 5 years , 3 follow-up assessment s were made by postal question naire . At all measuring points , pain intensity ratings and disability scores were compared between men and women , and among 3 exercise categories . Results . The pain intensity and disability scores were improved after 5 years for both men and women . The most prominent improvements occurred after 6 months , but less so thereafter . There were no significant differences between men and women with regard to individual changes at the 5-year follow-up concerning the pain intensity or disability scores . There were no significant differences , either for women or men , between low , median , or high intensity exercise groups regarding pain intensity or disability values for the individual change at the 5-year follow-up . Conclusions . Over a 5-year period , both men and women who had sought care for LBP reported a decrease in pain and disability ; however , only a few were fully restored . In this study , we found no effect of nonspecific physical exercise on recovery from LBP in men and women Study Design . Prospect i ve case series with historical controls ( normative data ) . Objectives . To compare the aerobic fitness level of patients with chronic low back pain ( CLBP ) with healthy controls matched for gender , age , and level of sport activity and to evaluate the association of the difference in aerobic fitness level with pain intensity , duration and degree of disability , fear of injury , and level of activity during work , including household and leisure time . Summary and Background Data . Controversy exists whether patients with CLBP have a lower level of aerobic fitness and whether this level may partly depend on the patients ’ activity level . Methods . A total of 108 CLBP patients completed question naires regarding pain , disability , fear of injury , and activity level  and performed a modified Åstr and submaximal cycling test . The maximum oxygen consumption ( VO2max ) was calculated and compared with normative data . Multiple linear regression analysis was performed with the difference of the level of aerobic fitness as dependent variable . Results . VO2max could be calculated in 78 % of the patients . Both men and women with CLBP had significant lower VO2max than the healthy referents ( 10 mL/kg LBM • min−1 and 5.6 mL/kg LBM • min−1 respectively , P < 0.001 ) , and this difference was significantly greater in men ( P = 0.03 ) . Multiple regression analysis showed that the level of aerobic fitness was not associated with the presumed variables . The patients who stopped the test prematurely were older ( P = 0.02 ) and more disabled ( P = 0.01 ) . Conclusion . CLBP patients , especially men , seem to have a reduced aerobic fitness level compared with the normative population . No explanatory factor for that loss could be identified OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity BACKGROUND AND PURPOSE Therapeutic exercise has been shown to be beneficial in decreasing pain and in increasing functioning in patients with chronic low back pain . However , longitudinal follow-up studies are small in number , and often limited in the numbers of subjects due to drop-outs . In addition there is a shortage of real control groups in most cases . The purpose of the present study was to describe long-term changes in intensity of low back pain and in functioning for two study groups five years after undertaking a home exercise programme . METHOD This was a r and omized follow-up study over five years . Fifty-seven subjects were reassessed with question naires five years after their initial recruitment for an intervention study . A home exercise group ( n = 29 ) , with training once a day , and a control group ( n = 28 ) , without exercise , were included in the present study protocol . The primary outcome measurements included a question naire on the intensity of low back pain ( Borg CR-10 scale ) and on functioning ( Oswestry Disability Index ; ODI ) . The confounding physical activity was controlled with metabolic unit ( MET ) values . RESULTS The CR-10 and ODI scores decreased during the first three months in both study groups . During the follow-ups , the corresponding indicators of the home exercise group remained below baseline values . The CR-10 score was significantly lower in the home exercise group ( p = 0.01 ) during the last five-year follow-up session compared with the control group . Overall physical activity decreased slightly during the five-year follow-up , but there were no differences between the two study groups . CONCLUSIONS The present r and omized study indicates that supervised , controlled home exercises lead to reduced low back pain , and that positive effects were preserved over five years Study Design . Prospect i ve case series with historical controls ( normative data ) . Objectives . To compare aerobic fitness levels in patients with chronic low back pain with those published on a sample of 295 healthy subjects . Summary of Background Data . Clinical belief holds that patients with chronic low back pain have low fitness levels as a result of inactivity because of pain . Because few studies have investigated the level of aerobic fitness in these patients , however , it remains unclear how fitness levels in patients with chronic low back pain patients compare with those published a sample of the normative population . Methods . A sample of 50 patients with chronic low back pain with a mean pain duration of 40 months referred to an outpatient pain clinic performed a  symptom-limited modified treadmill test .  Aerobic fitness levels were determined by indirect calorimetry to measure oxygen consumption ( VO2 ) . Predicted maximum oxygen consumption ( VO2max ) levels were calculated for all subjects . Multiple regression analysis with adjustment for age and sex yielded prediction equations for men and women separately . Ninety-five percent confidence intervals were calculated for predicted mean oxygen consumption ( VO2 ) and the slope of the equations . These were compared to established prediction equations on healthy subjects . Results . Prediction equations for estimated maximum oxygen consumption ( VO2max ) in patients with chronic low back pain equal those in healthy sedentary men and active women . Conclusions . Levels of aerobic fitness in patients with chronic low back pain are comparable with those in healthy subjects Background : Low back pain is a common medical and social problem associated with disability and absence from work . Knowledge on effective return to work ( RTW ) interventions is scarce . Objective : To determine the effectiveness of grade d activity as part of a multistage RTW programme . Design : R and omised controlled trial . Setting : Occupational healthcare . Subjects : 112 workers absent from work for more than eight weeks due to low back pain were r and omised to either grade d activity ( n = 55 ) or usual care ( n = 57 ) . Intervention : Grade d activity , a physical exercise programme aim ed at RTW based on operant-conditioning behavioural principles . Main outcome measures : The number of days off work until first RTW for more then 28 days , total number of days on sick leave during follow up , functional status , and severity of pain . Follow up was 26 weeks . Results : Grade d activity  prolonged RTW . Median time until RTW was equal to the total number of days on sick leave and was 139 ( IQR = 69 ) days in the grade d activity group and 111 ( IQR = 76 ) days in the usual care group ( hazard ratio = 0.52 , 95 % CI 0.32 to 0.86 ) . An interaction between a prior workplace intervention and grade d activity , together with a delay in the start of the grade d activity intervention , explained most of the delay in RTW ( hazard ratio = 0.86 , 95 % CI 0.40 to 1.84 without prior intervention and 0.39 , 95 % CI 0.19 to 0.81 with prior intervention ) . Grade d activity did not improve pain or functional status clinical ly significantly . Conclusions : Grade d activity was not effective for any of the outcome measures . Different interventions combined can lead to a delay in RTW . Delay in referral to grade d activity delays RTW . In implementing grade d activity special attention should be paid to the structure and process of care BACKGROUND In a pilot study for the European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) a modification of the Baecke question naire on physical activity was tested for repeatability and relative validity in a population of 134 men and women aged 20 - 70 years . METHODS For the assessment of repeatability Pearson 's correlation coefficients and percentages of agreement after classification in tertiles were computed between administrations of the question naire at baseline , and after 5 and 11 months . Relative validity was determined by comparing the question naire to a four times repeated 3-day activity diary . RESULTS Repeatability after 5 and 11 months was good , with test-retest correlation coefficients between 0.65 and 0.89 for main sections of the question naire . The percentages of agreement , exceeding chance ( Cohen 's kappa ) were 57 % and 56 % for men ( at 5 and 11 months respectively ) and 41 % and 46 % for women . The correlations with the diaries were 0.56 in men and 0.44 in women . Agreement apart from chance between classification in tertiles for both methods was 35 % for men and 10 % for women . CONCLUSIONS These data show that repeatability is good and relative validity as compared to an activity diary is moderate but well within the range of values found in other studies . The question naire is more valid in men than in women OBJECTIVE To investigate whether personal and work-related factors , physical performance and back-specific question naires predict return to work . A prospect i ve study identifying prognostic factors for return to work . SUBJECTS Ninety-three patients sick-listed for 8 - 12 weeks for non-specific sub-acute low back pain included in a r and omized controlled trial . METHODS Patients were examined with regard to demographic variables , a battery of back-specific question naires and physical tests before entering a r and omized controlled trial . A stepwise backward Cox regression model was established to identify the most powerful predictors . RESULTS During follow-up 78.5 % of the patients have returned to full-time work . Fear-avoidance beliefs for work ( relative risk ( RR ) for 1 SD change 0.49 ; 95 % confidence interval ( CI ) 0.38 - 0.64 ) , disability ( RR 1.39 , 95 % CI 1.02 - 1.88 ) and cardiovascular fitness ( RR 1.42 , 95 % CI 1.12 - 1.79 ) were identified as the best predictors for return to work . The prevalence of correct predictions was 69.3 % . CONCLUSION The predictors identified in the present study may reflect personal risk factors in a patient who gets acute low back pain . On the other h and , they may support that fear of pain and injury may be more disabling than pain itself , and that deconditioning is a result of altered behaviour reflecting attitudes towards low back pain in society , and information and advice given in primary healthcare OBJECTIVES We sought to estimate the effects of recreational physical activity and back exercises on  low back pain , related disability , and psychological distress among patients r and omized to chiropractic or medical care in a managed care setting . METHODS Low back pain patients ( n=681 ) were r and omized and followed for 18 months . Participation in recreational physical activities , use of back exercises , and low back pain , related disability , and psychological distress were measured at baseline , at 6 weeks , and at 6 , 12 , and 18 months . Multivariate logistic regression modeling was used to estimate adjusted associations of physical activity and back exercises with concurrent and subsequent pain , disability , and psychological distress . RESULTS Participation in recreational physical activities was inversely associated -- both cross-sectionally and longitudinally -- with low back pain , related disability , and psychological distress . By contrast , back exercise was positively associated -- both cross-sectionally and longitudinally -- with low back pain and related disability . CONCLUSIONS These results suggest that individuals with low back pain should refrain from specific back exercises and instead focus on nonspecific physical activities to reduce pain and improve psychological health Although r and omized controlled design s are considered the so-called gold st and ard in medical trials and sit atop the hierarchy of evidence in evidence -based medicine , there are situations in which they are impractical or unethical to undertake , especially in surgical trials . Then , observational studies often provide the best source of information . In this paper , we use examples from the literature to explain the importance of observational studies in furthering the boundaries of orthopaedic surgery and knowledge of musculoskeletal disorders Objective Research studies focussing on the fear-avoidance beliefs model ( FABM ) have exp and ed considerably during the last years , however , there has been very little research directed at the elderly . The objective of the present study was to investigate the validity of the FABM in older patients with chronic low back pain ( CLBP ) . Method In a cross-sectional study , a group of elderly patients with CLBP ( N=103 ) was compared with an age-matched group of pain-free individuals ( N=59 ) to test the constructs inherent in the FABM . Constructs include  fear avoidance beliefs ( FABs ) , disability , disuse , and physical activity . In addition , the relationship of these constructs was also investigated in the patient group . CLBP- patients had an average age of 71.41 years ( SD=5.2 ) and pain-free individuals of 71.19 years ( SD=4.73 ) . Individuals participated in a photographed series of physical activities adapted to the age group ( Photograph Series of Daily Activities-German version for the elderly ) for the assessment of FAB , in the Hannover Disability Question naire , in the Freiburg Physical Activity Question naire , and in an ultrasound measurement to evaluate lumbar flexion . In addition , they completed an activity diary for 1 week . Before computation , the physical activity measurements were converted into metabolic units that characterize energy expenditure . Results In the patient group , FAB , pain intensity , and age predicted functional capacity , but not physical activity . Lumbar flexion was predicted by FAB and age . Patients were more fear-avoidant , reported more disability , and displayed less lumbar flexion than the pain-free individuals . No differences between the groups could be detected in regard to energy expenditure measured either by the question naire or by diary data . Conclusions The findings are consistent with results reported in the literature for younger age groups and confirm the assumption that the FABM is also valid for the elderly
target: These data suggest that the activity levels of patients with NSLBP are neither associated with , nor predictive of , disability or pain levels .
background: Although clinical guidelines advocate exercise and activity in the management of non-specific low back pain ( NSLBP ) , the link between levels of physical activity and outcomes is unclear .
  This systematic review investigated the relationships between free living activity levels  after onset of low back pain ( LBP ) and measures of pain , and disability in patients with NSLBP .