Loss of Productivity Due to Neck/Shoulder Symptoms and Hand/Arm Symptoms : Results from the PROMO-Study Introduction The objective of the present study is to describe the extent of productivity loss among computer workers with neck/shoulder symptoms and hand/arm symptoms , and to examine associations between pain intensity , various physical and psychosocial factors and productivity loss in computer workers with neck/shoulder and hand/arm symptoms . Introduction Neck/shoulder and hand/arm symptoms are a common problem in society , in particular among the working population . In the European Union , in 2000 and 2001 , 23 % of the working population reported work-related pain in neck or shoulders . The percentage reporting work-related muscular pain in the upper limbs was about 13 % in the old member states and 20 % in the new member states -LSB- 1 -RSB- . Although it is not clear to what extent work-related factors contribute to their origin , their impact on working life is huge . Neck/shoulder and hand/arm symptoms can interfere with activities at work , and can cause sickness absence and chronic occupational disability . In the Netherlands in 2001 , incident cases of chronic disability for work due to neck and upper limb symptoms added up to 0.1 % of the working population , and 6 % of the total number of new disability benefits -LSB- 2 -RSB- . Besides sickness absence and chronic disability , neck/shoulder and hand/arm symptoms could also lead to reduced work effectiveness . Many workers still go to work despite the feeling that , in the light of their health , they should have taken sick leave . This phenomenon is known as sickness presenteeism -LSB- 3 -RSB- . Although they are present at work , their productivity could be reduced due to functional limitations . The extent of productivity loss while present at work is uncertain , but it has been suggested that it accounts for the majority of lost productivity costs associated with chronic pain -LSB- 4 , 5 -RSB- . Therefore , more knowledge is needed to estimate the magnitude of productivity loss associated with neck/shoulder symptoms and hand/arm symptoms . Not all musculoskeletal symptoms involve sickness absence or productivity loss . It would be interesting to know more about factors that might influence productivity loss in symptomatic workers . We are inclined to think that these factors might be similar to risk factors for the occurrence of symptoms or for sickness absence due to musculoskeletal symptoms . However , this is not necessarily true and these factors could easily diverge . Knowledge on both types of risk factors is important for primary , secondary and tertiary prevention . While knowledge on risk factors for the occurrence of symptoms is required to prevent them , knowledge on factors associated with productivity loss is needed in the process of retention , reintegration and rehabilitation of workers with symptoms . Previous studies have shown that pain characteristics , like pain intensity or severity , were predictive factors for a poor prognosis of musculoskeletal symptoms -LSB- 6 -- 9 -RSB- . Therefore , it seems plausible that high pain intensity will also have an impairing effect on productivity . Besides pain characteristics , physical , psychosocial and personal factors might affect productivity . In previous studies these factors were already identified as risk factors for the occurrence of symptoms -LSB- 10 -- 14 -RSB- . However , as mentioned earlier , this does not necessarily mean they also affect productivity loss in symptomatic workers . The present study is different from studies examining risk factors for sickness absence , as productivity is a broader outcome measure . Moreover , the study population of this study consists of symptomatic workers , and distinguishes between symptomatic workers with and without productivity loss . Studies examining risk factors for sickness absence are usually held in a mixed study population and usually distinguish healthy and symptomatic workers from workers with sickness absence . The objective of the present study is to describe the extent of productivity loss among computer workers with neck/shoulder symptoms and hand/arm symptoms , and to examine associations between pain intensity , various physical and psychosocial factors and productivity loss in computer workers with neck/shoulder and hand/arm symptoms . Methods Study Population Data were used from the baseline measurement of the PROMO-study : Prospective Research On Musculoskeletal Disorders in Office Workers -LSB- 15 -RSB- . The main purpose of this study was to determine risk factors for neck/shoulder symptoms and hand/arm symptoms among computer workers . The study design was approved by the Medical Ethics Committee of the VU University Medical Center . The study included workers from five different companies . The five participating companies comprised an insurance company , a department of a university , a public transport company , a brewery , and a financial consultancy firm . Employees from these companies had administrative , professional or management jobs . Altogether approximately 9,000 employees were working in these companies . All employees were invited to participate in the study . To maximize the participation rate , various activities were arranged , varying from the dissemination of brochures to visits at the worksite . Almost 2,500 employees subscribed to the project and signed informed consent . They were requested by e-mail to fill out an electronic questionnaire , accessible via the Internet . Participants who did not want to fill out an electronic questionnaire could fill out a paper version . Out of these employees , 1,951 filled out the questionnaire at baseline , resulting in a response rate of 79 % of the subscribed employees . In the PROMO-study , productivity loss due to neck/shoulder and hand/arm symptoms was self-reported and only assessed in workers reporting symptoms . Therefore , analyses concerning associations between various factors and productivity were limited to respondents reporting work-related neck/shoulder symptoms or hand/arm symptoms during the past three months . This selection contained 654 computer workers . Productivity Loss Productivity loss was only assessed for those respondents that reported regular or prolonged neck/shoulder symptoms or hand/arm symptoms in the past three months . A dichotomous variable was constructed , based on the answers on the following questions : -LRB- 1 -RRB- ` Have your symptoms slowed down your work pace ? ' ; -LRB- 2 -RRB- ` Have your symptoms decreased your working hours ? ' ; or -LRB- 3 -RRB- ` Have your symptoms caused disability to work for one or more days ? ' These questions were adapted versions of items used in the Swedish questionnaire used in the epi-mouse study . In the epi-mouse study , questions on productivity loss were validated through interviews -LSB- 16 -RSB- . They were asked for neck/shoulder symptoms and for hand/arm symptoms separately and referred to the past three months . If one or more of these questions were answered affirmative , it was defined as productivity loss . It was assumed that respondents answering that their symptoms decreased their working hours -LRB- 2 -RRB- , but did not cause disability for work -LRB- 3 -RRB- , had not been on sick leave . Only if the question concerning disability for work was answered affirmatively , it was defined as sickness absence . Neck/Shoulder Symptoms and Arm/Hand Symptoms In the questionnaire subjects were separately asked about symptoms in the neck/shoulder region and in the arm/hand region . The reason to separate these regions is the expected difference in relationship between symptoms and computer usage ; computer usage seems to have more effect on arm/hand symptoms than on neck/shoulder symptoms -LSB- 17 -RSB- . In the present study the distinction between the regions was maintained , because the different relationship with computer usage might result in different effects on productivity loss . Subjects were asked to rate the occurrence of pain or discomfort in the neck/shoulder region as well as in the hand/arm region in the previous 3 months on a four-point scale : ` no , never ' ; ` yes , sometimes ' ; ` yes , regularly ' ; ` yes , prolonged . ' Subsequently , subjects were asked to estimate whether these symptoms were related to their work , which they could answer with ` yes , completely ' ; ` yes , partly ' ; ` possibly ' or ` no . ' Also , 8 possible specific causes of these symptoms were summed : sport injuries , accidents , skin diseases , a twist or sprain , a cut or burn , a congenital defect , rheumatic disorders and a slipped disc . Neck/shoulder symptoms and arm/hand symptoms were defined as regular or prolonged pain , completely , partly or possibly related to work , and not caused by any listed specific cause . Independent Variables To examine which factors are associated with productivity loss in computer workers with neck/shoulder and hand/arm symptoms , analyses were carried out with the following variables : pain intensity , physical activity in leisure time -LRB- with BMI as a possible confounder -RRB- , working hours , mouse position , psychosocial load and overcommitment . Intensity of Symptoms The intensity of symptoms was measured using Von Korff scales -LSB- 18 -RSB- . Respondents were asked to indicate the mean intensity of their symptoms in the past three months on a scale ranging from 0 -LRB- no pain -RRB- to 10 -LRB- worst pain ever -RRB- . If they reported symptoms in both neck/shoulder and hand/arm region , the region with the highest score was used in the analyses . Physical Activity and BMI Concerning physical activity , the respondents were asked about the number of days per week they usually performed activities of at least moderate intensity , and about the times per week they usually performed activities of vigorous intensity . One variable with three categories was constructed measuring physical activity . The categories were ` no significant physical activity , ' ` moderate intensity physical activity , but no physical activity of vigorous intensity , ' and ` vigorous intensity physical activity . ' Moderate intensity physical activity was defined as performing physical activity causing increased breathing for at least 30 min per day with a frequency of at least 5 days per week -LSB- 19 , 20 -RSB- . Vigorous intensity physical acitivity was defined as performing physical activity causing sweating for at least 20 min per session with a frequency of at least 3 days per week -LSB- 21 , 22 -RSB- . BMI was computed by body weight -LRB- kg -RRB- divided by square of height -LRB- m2 -RRB- . Data on weight and height were self-reported . Working Hours Respondents were asked how many hours per week they worked according to their contract . A dichotomous variable was constructed that distinguished between full-time workers working 37 -- 40 h and part-time workers working 4 -- 36 h per week . Mouse Position Respondents were asked about the position of their mouse while using it . This question was illustrated with five possible positions for respondents to select , and a category ` other position . ' A dichotomous variable was constructed that distinguished between a mouse position close to the keyboard , and positions further away from the keyboard . This dichotomization corresponds to the dichotomization in previous research of Hagberg et al. , who defined nonoptimal computer mouse position as : `` Those who marked their computer mouse position outside a rectangle close to the operator in a workplace layout figure in the questionnaire '' -LSB- 16 -RSB- . Psychosocial Load To assess psychosocial load , two concepts were used , namely effort-reward imbalance and job satisfaction . For the first concept Siegrist 's Effort-Reward Imbalance model -LRB- ERI -RRB- was used -LSB- 23 , 24 -RSB- . The theory of this model is that a combination of high effort and low reward could lead to adverse health effects . Effort and reward were measured with the recommended scales of the ERI-model -LSB- 25 -RSB- . A validated Dutch version of the questionnaire was used -LSB- 26 -RSB- with scores varying from 1 -LRB- ` agree ' -RRB- to 5 -LRB- ` disagree , and I am very distressed ' -RRB- . Many different methods have been used to construct a variable indicating ERI -LSB- 27 -RSB- . In this study a variable in four categories was constructed : no high effort and no low reward , high effort -LRB- but no low reward -RRB- , low reward -LRB- but no high effort -RRB- and both high effort and low reward . High effort was assigned when a respondent reported to be distressed or very distressed about one or more of the 5 effort items . Low reward was assigned when a respondent reported to be distressed or very distressed about one or more of the 11 reward items . Cronbachs α was 0.68 for the effort scale and 0.80 for the reward scale . To assess job satisfaction respondents were asked how they enjoyed their work . To answer this question four categories were presented : ` never , ' ` sometimes , ' ` often , ' and ` always . ' This variable was dichotomized , resulting in a positive score on job satisfaction containing the responses ` often ' or ` always , ' and a negative score containing the responses ` never ' or ` sometimes . ' Personal Factor -- Overcommitment Concerning personal factors , the personality trait overcommitment was assessed . The concept `` overcommitment '' specifies those cognitive , emotional and motivational components within the global concept of Type A behavior that are important in coping with work demands . Overcommitted workers may expose themselves more often to high demands at work , or they may exaggerate their efforts beyond what is formally needed -LSB- 25 -RSB- . Overcommitment was assessed with the short version of a standard questionnaire -LSB- 23 -- 25 -RSB- . Subjects were asked if they strongly disagreed , disagreed , agreed or strongly agreed on 6 items -LRB- e.g. , I get easily overwhelmed by time pressures at work -RRB- . Scores were dichotomized -LRB- agree versus disagree -RRB- and the added scores on these items resulted in an overcommitment score ranging from 0 to 6 . Cronbachs α of the overcommitment scale was 0.74 . Analysis First , descriptive statistics were used to examine how often symptoms resulted in productivity loss , and to describe the components of productivity loss in terms of sickness absence and decreased performance at work . The association between productivity loss and several determinants was examined with logistic regression analyses using productivity loss as the dichotomous outcome variable . Univariate and multivariate analyses were carried out . In all multivariate analyses , age , gender , level of education , and intensity of symptoms were included as covariates . For the analysis with physical activity , BMI was checked for confounding and for the analysis with the psychosocial work characteristics , the other psychosocial work characteristics were checked for confounding . If their inclusion in the model did not result in a change of more than 10 % in the effect estimate , these covariates were not considered as a confounder and not included in the final model . Results Productivity Loss Figure 1 shows that neck/shoulder symptoms were reported more frequently than hand/arm symptoms . Of the total population 10 % reported both symptoms . On average , in 26 % of the cases reporting symptoms , productivity loss was involved . If both symptoms were reported , they were more often accompanied by productivity loss -LRB- 36 % -RRB- . Fig. 1Distribution of neck/shoulder and hand/arm symptoms in a population of computer workers -LRB- n = 1,951 -RRB- , and the fraction involving productivity loss within workers reporting symptoms Figure 2 shows what part of productivity loss was caused by sickness absence and what part was caused by a decreased performance at work . A decreased performance at work means decreased speed or decreased working hours , but no sickness absence . In 32 % of all cases reporting productivity loss , this productivity loss was coming from sickness absence . Sickness absence occurred more frequently in workers reporting both symptoms -LRB- 43 % -RRB- . Among workers reporting arm/hand symptoms , and no neck/shoulder symptoms , productivity loss was composed mainly of decreased productivity at work . Only 11 % of these workers reporting productivity loss have been on sick leave during the last 3 months . Fig. 2Distribution of productivity loss due to neck/shoulder symptoms , hand/arm symptoms or both in a symptomatic population of computer workers -LRB- n = 654 -RRB- and the fraction involving sickness absence within symptomatic workers reporting productivity loss Associations with Productivity Loss Table 1 shows odds ratios resulting from the logistic regression analyses . A higher odds ratio represents a higher probability of productivity loss . Pain intensity and psychosocial load , i.e. , high effort and low job satisfaction were associated with productivity loss in computer workers with neck/shoulder or arm/hand symptoms . In the analyses of the psychosocial work characteristics , the other psychosocial work characteristics were identified as confounders , while inclusion of physical activity in the model did not change the odds ratios for more than 10 % . Table 1Associations with productivity loss in a symptomatic population of computer workers -LRB- n = 654 -RRB- % -LRB- n -RRB- Crude OR -LRB- 95 % CI -RRB- Adjusted * OR -LRB- 95 % CI -RRB- R2N if item deletedFull model ** .140 Pain intensity Continuous measure -LRB- 0 -- 10 -RRB- 1.24 -LRB- 1.13 -- 1.37 -RRB- 1.26 -LRB- 1.12 -- 1.41 -RRB- .104 Physical activity in leisure time No significant physical activity63 -LRB- 408 -RRB- 1.001.00.131 Moderate intensity -LRB- 5 × 30 min/week -RRB- 22 -LRB- 141 -RRB- 0.73 -LRB- 0.46 -- 1.17 -RRB- 0.74 -LRB- 0.43 -- 1.27 -RRB- Vigorous intensity -LRB- 3 × 20 min/week -RRB- 16 -LRB- 99 -RRB- 1.48 -LRB- 0.92 -- 2.39 -RRB- 1.27 -LRB- 0.70 -- 2.27 -RRB- Working hours Part-time -LRB- 4 -- 36 h -RRB- 61 -LRB- 399 -RRB- 1.001.00.135 Full-time -LRB- 37 -- 40 h -RRB- 39 -LRB- 255 -RRB- 1.37 -LRB- 0.96 -- 1.96 -RRB- 1.36 -LRB- 0.87 -- 2.11 -RRB- Mouse position Close to the keyboard35 -LRB- 229 -RRB- 1.001.00.134 Other position65 -LRB- 425 -RRB- 0.93 -LRB- 0.64 -- 1.34 -RRB- 0.70 -LRB- 0.45 -- 1.08 -RRB- Psychosocial loadEffort-Reward Imbalance No high effort , no low reward40 -LRB- 258 -RRB- 1.001.00.115 No high effort , low reward20 -LRB- 130 -RRB- 1.81 -LRB- 1.10 -- 2.99 -RRB- 1.43 -LRB- 0.76 -- 2.67 -RRB- High effort , no low reward18 -LRB- 119 -RRB- 1.89 -LRB- 1.14 -- 3.16 -RRB- 2.26 -LRB- 1.24 -- 4.12 -RRB- High effort , low reward21 -LRB- 138 -RRB- 2.69 -LRB- 1.68 -- 4.32 -RRB- 1.95 -LRB- 1.09 -- 3.50 -RRB- Job satisfaction/task enjoyment Always21 -LRB- 138 -RRB- 1.001.00.110 Often65 -LRB- 423 -RRB- 1.29 -LRB- 0.80 -- 2.08 -RRB- 1.62 -LRB- 0.89 -- 2.92 -RRB- Never/sometimes14 -LRB- 93 -RRB- 3.10 -LRB- 1.72 -- 5.58 -RRB- 3.10 -LRB- 1.44 -- 6.67 -RRB- Overcommitment Continuous measure -LRB- 0 -- 6 -RRB- 1.06 -LRB- 0.96 -- 1.16 -RRB- 1.09 -LRB- 0.97 -- 1.22 -RRB- .140 Abbreviations : OR , odds ratio ; CI , confidence interval ; R2N : Nagelkerke R2 index of global model fit -LRB- 0 = lack of fit , 1 = perfect fit -RRB- * Adjusted for gender , age , level of education and intensity of symptoms ; the analyses with effort-reward imbalance were additionally adjusted for job satisfaction and the analyses with job satisfaction were additionally adjusted for effort-reward imbalance ** The full model contained gender , age , level of education and all variables mentioned in the table Physical activity in leisure time , working hours , mouse position and overcommitment were not associated with productivity loss in computer workers with neck/shoulder symptoms or arm/hand symptoms . Additional adjustment for BMI in the analyses with physical activity did not result in a change in odds ratio for more than 10 % . Discussion The purpose of this study was to describe the extent of productivity loss among computer workers with neck/shoulder symptoms and hand/arm symptoms and to examine associations between various physical , psychosocial and personal factors and productivity . The results show that in 26 % of all cases reporting regular or prolonged symptoms in the past three months , productivity loss was involved . Most productivity loss was found in workers reporting both neck/shoulder symptoms and hand/arm symptoms . Overall , about 32 % of the productivity loss was coming from sickness absence . Sickness absence occurred more frequently in workers reporting both symptoms -LRB- 43 % -RRB- and considerably less frequent in workers reporting only hand/arm symptoms -LRB- 11 % -RRB- . Symptomatic workers reporting unfavorable psychosocial work characteristics reported more productivity loss . Comparison with Previous Research The study population of the present study consisted of office workers with neck/shoulder or hand/arm symptoms . So far , almost all studies using productivity loss as an outcome measure were studies in a mixed population , containing subjects with and without musculoskeletal symptoms . Moreover , most previous research on productivity loss concerned sickness absence , while in the present study a decreased productivity while working was also included . Therefore , the results of previous studies are hard to compare with the present study . In a mixed population , associations between productivity loss and potential risk factors partly reflect the risks for symptom occurrence . In the present study we wanted to examine which factors are related to decreased productivity once symptoms have occurred . These factors do not have to be similar . Nevertheless , we will mention the results of previous research in this section . In the present study , physical activity in leisure time was not significantly associated with productivity loss in workers with neck/shoulder or hand/arm symptoms . We did not find other studies in a symptomatic working population . A few studies have examined the relation between physical activity and productivity loss in a general population . These studies often found a favorable effect of physical activity . A favorable effect was found of sporting activity on sick leave in general -LSB- 28 -RSB- , and in particular sick leave due to musculoskeletal disorders -LSB- 29 , 30 -RSB- . Also an association was found between higher levels of physical activity and job performance -LSB- 31 -RSB- . It seems that physical activity has a preventive effect and is positively associated with productivity , but does not affect productivity loss in workers already having symptoms . The present study did not examine the association between physical load and productivity loss extensively . Our hypothesis was that computer workers with a high physical load -LRB- for example adverse ergonomic working conditions or sustained computer or mouse usage -RRB- might experience more productivity loss . Conversely , some studies in a general working population examining the effect of the improvement of ergonomic working conditions have shown beneficial effects on productivity -LSB- 32 , 33 -RSB- . An observational study found a weak association between an adverse mouse position and productivity loss -LSB- 16 -RSB- in workers with musculoskeletal symptoms . The present study could not confirm the relation between an adverse mouse position and productivity loss . It might be more interesting to examine the relation between productivity loss and duration of computer use , since studies show that duration is more consistently associated with musculoskeletal symptoms than posture -LSB- 10 , 17 -RSB- . However , the design of the present study is not suitable to examine this relationship . The results of the analyses would produce a biased view , because in a population of computer workers , productivity loss means almost automatically less computer usage . Preliminary analyses confirmed this assumption : in the subpopulation of symptomatic computer workers , those reporting productivity loss also reported less computer usage , in particular mouse usage . Therefore , analyses examining the association between computer usage and productivity loss would result in a negative association , i.e. , more computer usage , less productivity loss . However , we did examine the association with part-time versus full-time work , because this variable is probably not biased . Respondents were asked how many hours they worked according to their contract . The distinction might indicate a form of physical load , assuming that full-time workers are exposed to a higher physical load . Nevertheless , no relation was found between productivity loss and part-time/full-time work . No previous studies were found examining this relationship . Psychosocial load , in this study defined as effort-reward imbalance and job satisfaction , was strongly associated with productivity loss . No studies were found that examined these psychosocial work characteristics in relation to productivity loss or sickness absence due to musculoskeletal symptoms . Also , no studies were found that examined the relation between psychosocial work characteristics in general and productivity loss , other than sickness absence . Finally , no studies were found that examined these relations in a symptomatic population . In mixed populations , containing subjects with and without musculoskeletal symptoms , the relation between psychosocial load and sickness absence in general was demonstrated by several studies -LSB- 34 -- 36 -RSB- . Few studies have examined the relation with sickness absence due to musculoskeletal symptoms , and their results were conflicting -LSB- 37 , 38 -RSB- . Limitations of the Study In the present study , self-reported data were used to assess productivity loss . Productivity loss in this study contains two components : absenteeism and presenteeism . Self-reported data on absenteeism have been found to be reliable and valid when the recall periods are short -LSB- 39 -RSB- . However , measuring presenteeism is more complex . For most types of employment , there is no objective account of productivity with which to assess an employee 's performance . In the present study computer usage was measured by a software program . Therefore , in this study population of computer workers it might be considered to use computer usage as a measure for productivity . We decided not to do so , because we assumed that differences in computer usage would be larger between jobs than between workers with and without productivity loss . For this reason , differences in computer usage would probably reflect different kinds of jobs instead of differences in productivity . The lack of objective instruments to measure productivity also hampers the validation of self-reported measures . One study , using a rather similar productivity measure , compared self-reported productivity loss assessed with a questionnaire with interviews of 50 computer users who had reported musculoskeletal symptoms -LSB- 16 -RSB- . The results seem to indicate that productivity loss assessed in the questionnaire could be a slight underestimation . Another limitation concerning the productivity measure is its dichotomy . No distinction could be made between a minimal and a major loss of productivity . It would be more accurate and it would provide more insight into the magnitude of the problem , if the precise size of the productivity loss was assessed . However , it is very hard for workers to estimate the size of their productivity loss . A recent review concluded that no study has shown that employees can accurately transform their perceived impairments into a quantitative measure -LSB- 39 -RSB- . Therefore , since objective instruments to measure productivity are lacking , we are forced to limit ourselves to a subjective dichotomous measure of productivity . Although in the PROMO-study follow-up measurements were available , we choose to use a cross-sectional design . The main reason is that data on productivity loss were only available for workers with symptoms . Since symptoms generally have an episodic nature the selection of workers with symptoms at baseline is not identical to the selection of workers with symptoms at follow-up . To select workers with data on productivity at baseline as well as at one or more of the follow-up measurements would mean a selection of workers with symptoms at all these measurements . Such a selection would result in a small study population of workers with chronic symptoms . If we assume that the associations in this study are causal , still the direction of causality can not be established due to the cross-sectional design . It could be that either psychosocial working conditions caused productivity loss , or productivity loss caused the reporting of adverse psychosocial working conditions , or both . Intervention studies focusing on the prevention of productivity loss among symptomatic workers might shed more light on the direction -LRB- s -RRB- of causality . Implications for Practice The results of this study show that employers should be aware that the consequences of neck/shoulder and hand/arm symptoms are more extensive than the visible sickness absence due to these symptoms . Only one third of workers who experience productivity loss due to their symptoms actually take sick leave . For the other workers productivity loss expresses itself in decreased performance at work . The results concerning factors associated with productivity loss are more difficult to interpret , since there is still a lack of knowledge on how they relate . It seems that symptomatic workers perform better in favorable psychosocial working conditions . An advantageous psychosocial climate might prevent productivity loss in symptomatic workers . In conclusion , most workers with neck/shoulder symptoms or hand/arm symptoms experience productivity loss from a decreased performance at work and not from sickness absence . Favorable psychosocial work characteristics might prevent productivity loss in symptomatic workers .

O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O B I O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O B I O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O B I O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B I O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B I O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B O O O O O O O O O O O O O O O O O O O B I O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O B I O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O

productivity
musculoskeletal symptoms
presenteeism
computer workers
psychosocial factors


Are Pain Intensity and Pain Related Fear Related to Functional Capacity Evaluation Performances of Patients with Chronic Low Back Pain ? Introduction : Pain related fear and pain intensity have been identified as factors negatively influencing Functional Capacity Evaluation -LRB- FCE -RRB- performances in patients with CLBP . Conflicting results have been reported in the literature . The objective of this study was to analyze the relationships between pain intensity and pain-related fear on the one hand , and performances during an FCE on the other hand in two samples of patients with chronic low back pain -LRB- CLBP -RRB- . Methods : Two cross sectional observation studies were performed with two samples of patients with CLBP -LRB- study 1 : n = 79 ; study 2 : n = 58 -RRB- . Pain related fears were operationally defined as the score on the Tampa Scale of Kinesiophobia in study 1 , and the Fear Avoidance Beliefs Questionnaire -LRB- FABQ -RRB- in study 2 . Pain intensity was measured with a Numeric Rating Scale in both studies . Avoidance behavior observed during FCE was in both studies operationally defined as the unwillingness to engage in high intensity performance levels of three different functional activities : high intensity lifting , prolonged standing in a forward bend position , and fast repetitive bending at the waist . Results : A total of 25 correlations between pain and pain related fear , and performance variables were calculated , out of which 7 were significant -LRB- p < 0.05 -RRB- . The strength of these significant correlations ranged from r = − 0.23 to r = − 0.50 . Multivariate linear regression analyses revealed non-significant relationships in most instances . Pain and pain related fear contributed little if any to these models . Conclusions : The relation between pain and pain related fear and FCE performance is weak or non-existent in patients with CLBP . Introduction Functional Capacity Evaluations -LRB- FCEs -RRB- are batteries of tests designed to assess a person 's functional capacity related to work -LSB- 1 -- 3 -RSB- . To establish functional capacity , the patient is asked to perform a number of activities . Combined , these performances reflect a patient 's ability to perform work-related activities . A patient 's performance is determined by biological , psychological and social factors -LSB- 4 -RSB- . Pain related fear , also referred to as fear avoidance beliefs or fear of movement and reinjury -LSB- 5 -RSB- , and pain -LSB- 6 -RSB- have been identified as examples of psychological factors influencing a patient 's performance during an FCE . Pain related fear refers to a condition in which the patient has an excessive , irrational , and debilitating fear of physical movement and activity , resulting in feelings of vulnerability to painful injury or reinjury -LSB- 7 , 8 -RSB- . People who experience pain-related fear will avoid activities they associate with increased risk for pain or -LRB- re -RRB- injury . As such , pain-related fear should have a negative effect on the results of performance testing -LSB- 5 , 9 -RSB- . It has been stated that ` a valid assessment of functional capacity can not be carried out without controlling for fear avoidance beliefs ' -LSB- 8 -RSB- . Several studies were performed to study the relationship between pain-related fear and different types of avoidance behavior in patients with chronic non-specific low back pain -LRB- CLBP -RRB- . The strength of this relationship varied between the studies from r = 0.06 to r = 0.49 -LSB- 8 -- 10 , 11 -RSB- . The relationship between pain related fear and performance appeared stronger in studies where patients were observed under strictly controlled conditions -LSB- 8 , 10 -RSB- , and weaker in studies where patients were observed in a less controlled environment -LSB- 11 -RSB- . In a previous study performed in an admission phase for a pain rehabilitation program , no relationship was found in a sample of patients with CLBP , between lifting performance and pain-related fear -LSB- 12 -RSB- . Although the evidence from other studies did not overwhelmingly support the strength of the relationship , our results , presented in the Journal of Occupational Rehabilitation in 2003 , were in contrast with other studies . It could not be determined whether the results found were weaker because of the operational definitions of pain-related fear -LRB- score on Tampa Scale for Kinesiophobia -LRB- TSK -RRB- -RRB- or avoidance behavior -LRB- maximum lifting performance -RRB- . It was recommended that future studies should use additional operational definitions for pain-related fear and avoidance behaviors . In a recent review pain intensity has been identified to consistently associate negatively with patient performances during FCEs -LSB- 6 -RSB- . The strength of the significant associations between pain intensity and FCE performances in patients with chronic pain vary from r = − 0.25 to r = − 0.56 -LSB- 6 -RSB- . In the study mentioned above , the relation between pain intensity and lifting performance was -LRB- somewhat -RRB- weaker and non-significant -LRB- r = − 0.21 -RRB- -LSB- 12 -RSB- . Aim of this study was to further analyze the relationships between pain intensity and pain-related fear on the one hand , and avoidance behaviors on the other hand . Two studies were performed with separate samples of patients with CLBP . Pain related fears were operationally defined as the score on the TSK in study 1 , and the Fear Avoidance Beliefs Questionnaire -LRB- FABQ -RRB- in study 2 . Avoidance behavior was in both studies operationally defined as the unwillingness to engage in high intensity performance levels of three different FCE tests : high intensity lifting , prolonged standing in a forward bend position , and fast repetitive bending at the waist . Non-significant or weak relationships were considered falsifications of the hypotheses that pain and pain-related fears would have clinically relevant impact on FCE performances in patients with CLBP . Materials and methods Patients Two separate cohorts of patients who were referred to an outpatient rehabilitation program of the Center for Rehabilitation of the Groningen University Medical Center , The Netherlands , were included . Both study samples consisted of patients diagnosed with CLBP , aged between 18 and 60 years , with symptoms lasting longer than 3 months . Excluded were patients with comorbidity with negative consequences for functioning -LRB- i.e. severe depression needing a psychiatric referral -RRB- , and patients with specific pathology related to the lumbar spine -LRB- i.e. disc herniations , tumors , spondylolisthesis grade 3 or 4 , etc. -RRB- . Patients were not selected based on -LRB- high or low -RRB- levels of pain or pain related fears . Selection process of both study samples were equal , with the exception that patients in study sample 1 explicitly agreed to participate in a larger study in addition to regular clinical care -LSB- 13 -RSB- . The patients of sample 2 received regular clinical care only . Procedures Prior to the medical intake patients filled out a TSK -LSB- 7 , 8 -RSB- , a numeric rating scale to assess pain intensity -LRB- NRS -RRB- , a Roland Morris Disability Questionnaire -LSB- 14 -RSB- -LRB- RMDQ -RRB- to assess disability , and a study consent form . The patients underwent the FCE approximately 2 weeks after the medical intake . Prior to the FCE , all patients were asked whether their pain and functional status was different compared to their status during medical intake . In study 2 , patients filled out the FABQ -LSB- 15 -RSB- prior to the FCE . For study 1 , approval was granted by the medical ethics committee of the University Medical Center Groningen , The Netherlands . The data of the patients of study sample 2 were collected as part of regular clinical procedures , for which institutional approval was received . Measures Patients rated their current pain intensity on a NRS ranging from 0 to 10 ; 0 being no pain at all and 10 being the worst pain imaginable . Self reported disability was assessed by the RMDQ -LSB- 14 -RSB- . Scores on the RMDQ can range from 0 to 24 ; 0 indicating no disability and 24 indicating severe disability . The psychometric properties of the RMDQ are good -LSB- 14 , 16 -RSB- . Pain related fear was assessed with a different questionnaire for each sample . In study 1 , pain related fear , called fear of movement and reinjury , was assessed by the TSK -LSB- 8 -RSB- . The TSK consists of 17 items . Each item is provided with a 4-point Likert scale with scoring alternatives ranging from `` strongly disagree '' to `` strongly agree . '' Although the scale consists of 2 subscales , activity avoidance and somatic focus , a total score is usually presented . The total score ranges from 17 to 68 . The reliability of the TSK is fair -LSB- 8 -RSB- . Criterion validity was established from correlations with other self-reported measures of fear -LRB- of bodily injury -RRB- , anxiety , depression , and catastrophizing -LSB- 8 -RSB- . In study 2 , pain related fear , called fear avoidance beliefs , was assessed by the FABQ -LSB- 10 , 15 -RSB- . The FABQ consists of 16 items . Each item is provided with a 7-point Likert scale with scoring alternatives ranging from 0 to 6 . The FABQ consists of 2 scales . The activity scale consists of 4 items -LRB- total score 0 -- 24 -RRB- , the work scale consists of 6 items -LRB- total score 0 -- 36 -RRB- . The remaining 4 items are not used . The reliability of the FABQ is good in patients with acute and subacute back pain -LSB- 17 -RSB- , but has not been established in patients with CLBP . Avoidance behavior was assessed during an FCE . The patients were asked to perform 14 different activities to their maximum abilities -LRB- 3 types of lifting , carrying , pushing , pulling , overhead work , stooping , crouching , kneeling , standing , walking , sitting , stair climbing -RRB- , according to the protocols of Isernhagen Work Systems -LSB- 18 -RSB- . Selection of activities was based on the Dictionary of Occupational Titles -LRB- DOT -RRB- , thus assuming construct validity with regard to work -LSB- 19 -RSB- . Three activities tested during the FCE were selected for this study , because they might be potentially harmful for patients with CLBP -LSB- 20 -RSB- . These activities were lifting , static bending and dynamic bending . Lifting was assessed by means of a standardized lifting task consisting of lifting a receptacle with incremental weights from a table -LRB- 74 cm -RRB- to the floor and vice versa . ` Ergonomically correct ' body mechanics were not emphasized -LSB- 21 -RSB- . The patient 's maximum was reached in four to five increments . The maximal amount lifted five times within 90 seconds was recorded -LRB- kilograms -RRB- . Test-retest reliability of the lifting task is good in patients with CLBP -LSB- 22 -- 24 -RSB- . During lifting , heart rate was measured using a heart rate monitor . In study 2 , the intensity level of lifting was observed by the evaluator , and recorded by means of a Borg CR-10 scale . The reliability and validity of this procedure is good -LSB- 25 -RSB- . These observations were not recorded in study 1 . During the static bending capacity test the patient was asked to stand as long as possible with his / her trunk 30 -- 60 ° flexed forward , while performing a simple manipulation task . The time this position was held was recorded -LRB- seconds -RRB- . Test-retest reliability of this test in patients with CLBP is good -LSB- 22 -RSB- . For the dynamic bending test , the patient is asked to bend at the hips and back as fast as possible , pick up a small object from the floor , and to remove this object to a shelf at crown level -LRB- top of head -RRB- . This was repeated 20 times . The number of repetitions completed and the time needed to complete this activity was recorded -LRB- seconds -RRB- . Test retest reliability of this test in patients with CLBP is moderate to good -LSB- 22 -RSB- . The construct validity of the tests has been established -LSB- 26 , 27 -RSB- . Before testing , patients were instructed regarding termination of the test . Testing was terminated when one of the following occurred : the patient stated verbally that he/she wished to terminate the activity , the heart rate reached 85 % of the age-related maximum , indicated by a heart rate monitor , or the evaluator deemed further testing to be unsafe . No verbal reassurance was given during the testing procedures . The evaluator was blinded to the questionnaire scores . Analysis Descriptive statistics were used to describe the study samples . All variables of interest were analyzed at interval level . A student t-test was used to analyze differences between males and females . When differences were significant , further analyses were performed separately for males and females . Pearson product moment correlations were calculated to express linear associations between pain intensity and measures of pain related fear on the one hand and performance variables on the other hand . Correlations were interpreted as follows : 0.25 or less little if any relationship , 0.26 -- 0.49 poor relationship , 0.50 -- 0.69 moderate relationship , 0.70 -- 0.89 strong relationship , 0.90 -- 1.00 very strong relationship -LSB- 28 -RSB- . Pain intensity and pain related fear , as well as gender , age and self-reported disability were entered as predictor variables in a multivariate linear regression model -LRB- method : enter -RRB- and performances as outcome variables . A p-value of < 0.05 was considered statistically significant for all analyses . Results The characteristics of the patients participating in study 1 and 2 are presented in Table 1 . All patients declared that their pain and functional status had not changed between medical intake and the FCE . Scores on the TSK subscale in study 1 are : activity avoidance males mean 19.1 -LRB- SD 3.8 -RRB- , females mean 18.9 -LRB- 3.3 -RRB- ; somatic focus males mean 9.7 -LRB- 2.5 -RRB- , females mean 9.2 -LRB- 2.6 -RRB- . The 20 repetitions of the dynamic bending test were not completed by 10 -LRB- of 79 , 13 % -RRB- patients in study 1 and by 6 -LRB- of 58 , 10 % -RRB- patients in study 2 . To correct for differences in number of repetitions , the time needed to complete one repetition was calculated and presented -LRB- time/number of repetitions -RRB- . The observed level of intensity of the maximal lifting performances in study 2 were for males mean 7.2 -LRB- SD 2.2 -RRB- and for females 7.4 -LRB- SD 1.6 -RRB- -LRB- Borg CR-10 scale -RRB- . Observational data was unavailable in study 1 . Within the study samples , differences between males and females were non-significant , with the exception of the maximum lifting performance . Between the study samples , none of the differences were significant . Table 1Age , pain intensity , self-reported disability , pain related fear -LRB- TSK or FABQ -RRB- , and performance variables of 2 samples of patients with chronic low back painStudy 1 -LRB- n = 79 -RRB- Study 2 -LRB- n = 58 -RRB- Males -LRB- n = 49 -RRB- Females -LRB- n = 30 -RRB- Males -LRB- n = 39 -RRB- Females -LRB- n = 19 -RRB- Mean -LRB- SD -RRB- Mean -LRB- SD -RRB- Mean -LRB- SD -RRB- Mean -LRB- SD -RRB- Age -LRB- years -RRB- 37.8 -LRB- 9.0 -RRB- 37.8 -LRB- 8.8 -RRB- 40.4 -LRB- 8.6 -RRB- 35.6 -LRB- 8.3 -RRB- Pain intensity -LRB- NRS ; 0 -- 10 -RRB- 4.7 -LRB- 2.3 -RRB- 5.0 -LRB- 1.6 -RRB- 4.5 -LRB- 2.4 -RRB- 4.9 -LRB- 2.2 -RRB- Self-reported disability -LRB- RMDQ ; 0 -- 24 -RRB- 12.5 -LRB- 4.4 -RRB- 12.4 -LRB- 4.7 -RRB- 11.6 -LRB- 4.4 -RRB- 11.2 -LRB- 5.9 -RRB- TSK -LRB- 17 -- 68 -RRB- 37.5 -LRB- 5.3 -RRB- 36.0 -LRB- 5.6 -RRB- N/AN/AFABQ activity scale -LRB- 0 -- 24 -RRB- N/AN/A13 .4 -LRB- 4.1 -RRB- 13.2 -LRB- 5.6 -RRB- FABQ work scale -LRB- 0 -- 36 -RRB- N/AN/A19 .3 -LRB- 9.5 -RRB- 15.1 -LRB- 11.6 -RRB- Lifting performance -LRB- kg -RRB- * 31.7 -LRB- 14.7 -RRB- 18.9 -LRB- 8.1 -RRB- 32.3 -LRB- 3.8 -RRB- 20.5 -LRB- 6.3 -RRB- Lifting maximum heart rate -LRB- BPM -RRB- 126.7 -LRB- 15.8 -RRB- 129.7 -LRB- 23.5 -RRB- 128.2 -LRB- 14.5 -RRB- 128.8 -LRB- 19.3 -RRB- Static forward bend -LRB- sec -RRB- 187.4 -LRB- 148.9 -RRB- 230.6 -LRB- 146.3 -RRB- 188.0 -LRB- 115.8 -RRB- 237.3 -LRB- 154.8 -RRB- Dynamic forward bend -LRB- sec/rep -RRB- 2.8 -LRB- 0.7 -RRB- 3.2 -LRB- 1.3 -RRB- 3.2 -LRB- 1.6 -RRB- 2.9 -LRB- 0.8 -RRB- SD : standard deviation ; NRS : Numeric Rating Scale ; RMDQ : Roland Morris Disability Questionnaire ; TSK : Tampa Scale for Kinesiophobia ; FABQ : Fear Avoidance Beliefs Questionnaire ; BPM : beats per minute ; N/A : not assessed . * : Difference between males and females significant in both studies -LRB- p < 0.05 -RRB- . Note . Differences between the study samples were non-significant -LRB- p < 0.05 -RRB- . A total of 25 correlations between pain intensity , TSK -LRB- study 1 -RRB- and FABQ -LRB- study 2 -RRB- and performance variables are presented in Table 2 . The strengths of the correlations were moderate in one occasion and otherwise weak/poor or non-significant . Pain intensity explained 25 % of the variance of the performances of male lifting performance in study 2 -LRB- r = − 0.50 -RRB- . In all other analyses over both studies , the explained variance between pain intensity and performance variables was 8 % -LRB- r = − 0.29 -RRB- or less . The FABQ work scale explained at best 13 % of the variance of the performances -LRB- male lifting performance in study 2 ; r = − 0.37 -RRB- . The correlation between either TSK subscales with any of the performance variables was non-significant . No differences were observed between patients who did or did not complete 20 repetitions of the dynamic bending test concerning their relationship with the TSK or the FABQ -LRB- all non-significant -RRB- . The correlation between observed intensity of lifting and FABQ work scale was r = − 0.27 -LRB- significant -RRB- . The correlation between observed lifting intensity and FABQ activity scale was r = − 0.07 -LRB- not significant -RRB- . Table 2Relationships between performance variables and pain intensity , the Tampa Scale for Kinesiophobia -LRB- TSK , study 1 ; n = 79 -RRB- and the Fear Avoidance Beliefs Questionnaire -LRB- FABQ , study 2 ; n = 58 -RRB- in patients with chronic low back pain . All relationships are expressed in Pearson 's r -LRB- 95 % CI -RRB- Study 1Study 2PainTSKPainFABQ activity scaleFABQ work scaleLifting performance males -LRB- kg -RRB- − 0.26 -LRB- − 0.57 to 0.11 -RRB- − 0.12 -LRB- − 0.46 to 0.25 -RRB- − 0.50 * -LRB- − 0.71 to − 0.22 -RRB- − 0.13 -LRB- − 0.43 to 0.19 -RRB- − 0.37 * -LRB- 0.06 to 0.61 -RRB- Lifting performance females -LRB- kg -RRB- − 0.06 -LRB- − 0.34 to 0.23 -RRB- − 0.17 -LRB- − 0.43 to 0.12 -RRB- 0.09 -LRB- − 0.52 to 0.38 -RRB- − 0.07 -LRB- − 0.51 to 0.40 -RRB- − 0.03 -LRB- − 0.48 to 0.43 -RRB- Lifting maximum heart rate -LRB- BPM -RRB- 0.05 -LRB- − 0.17 to 0.27 -RRB- − 0.10 -LRB- − 0.31 to 0.12 -RRB- − 0.27 * -LRB- − 0.49 to − 0.01 -RRB- − 0.24 -LRB- − 0.47 to 0.02 -RRB- − 0.24 -LRB- − 0.47 to 0.02 -RRB- Static forward bend -LRB- sec -RRB- 0.18 -LRB- − 0.04 to 0.39 -RRB- − 0.23 * -LRB- − 0.43 to − 0.01 -RRB- − 0.29 * -LRB- − 0.51 to − 0.03 -RRB- − 0.33 * -LRB- − 0.54 to − 0.08 -RRB- − 0.25 -LRB- − 0.48 to 0.01 -RRB- Dynamic forward bend -LRB- sec/rep -RRB- − 0.10 -LRB- − 0.31 to 0.12 -RRB- 0.14 -LRB- − 0.08 to 0.35 -RRB- 0.03 -LRB- − 0.23 to 0.29 -RRB- 0.07 -LRB- − 0.19 to 0.32 -RRB- 0.30 * -LRB- 0.05 to 0.52 -RRB- Note . TSK : Tampa Scale for Kinesiophobia ; FABQ : Fear Avoidance Beliefs Questionnaire ; BPM : beats per minute ; 95 % CI : 95 % confidence Interval . * p < 0.05 . Analyses were performed on the subgroups of patients scoring in the highest quartile of the pain intensity spectrum -LRB- study 1 , NRS ≥ 6 , n = 22 ; study 2 , NRS ≥ 7 , n = 17 -RRB- , the TSK -LRB- score ≥ 40 , n = 22 -RRB- , and the FABQ -LRB- activity scale ≥ 17 , work scale ≥ 25 , n = 16 -RRB- . Analyses involving lifting performances were performed for males and females separately . Correlation coefficients between pain intensity or pain related fears and performance variables ranged between r = 0.00 and r = 0.23 in study 1 , and between r = 0.00 and r = 0.26 in study 2 . All correlations were non-significant . Scatter plots of the distribution of pain intensity or pain related fears and performance variables were created to visually analyze patterns in the datasets . As an example , the distribution of pain related fear -LRB- TSK -RRB- and lifting performances is presented in Fig. 1 . Other distributions between pain intensity or pain related fears -LRB- TSK or FABQ -RRB- and performance variables were similar , but they are not presented.Fig . 1Plot of maximum lifting performance and scores on the Tampa Scale for Kinesiophobia -LRB- TSK -RRB- in 79 patients with chronic low back painTable 3Multivariate linear regression models predicting variance in performance in patients with chronic low back painβ -LRB- 95 % CI -RRB- Betapr2 changeModel r2Study 1 -LRB- n = 79 -RRB- Dependent variable : lifting • Gender -LRB- female = 0 , male = 1 -RRB- 14.45 -LRB- 7.36 to 21.54 -RRB- 0.48 < 0.0010.230.28 • Constant17 .01 -LRB- − 9.60 to 43.62 -RRB- -- 0.205 -- Dependent variable : static forward bend • Model r2 = 0.11 ; None of the independent variables contributed significantly to the regression equationDependent variable : dynamic forward bend • Model r2 = 0.12 ; None of the independent variables contributed significantly to the regression equationStudy 2 -LRB- n = 58 -RRB- Dependent variable : lifting • Gender -LRB- female = 0 , male = 1 -RRB- 14.94 -LRB- 6.15 to 23.73 -RRB- 0.480.0010.230.37 • Pain intensity − 1.83 -LRB- − 3.65 to − 0.01 -RRB- − 0.290.0490.08 • Constant -LRB- kg -RRB- 45.70 -LRB- 25.67 to 65.73 -RRB- -- < 0.001 -- Dependent variable : static forward bend • Constant -LRB- sec -RRB- 549.15 -LRB- 336.09 to 762.21 -RRB- -- < 0.001 -- 0.27 • None of the other independent variables contributed significantly to the regression equationDependent variable : dynamic forward bend • Model r2 = 0.18 ; None of the independent variables contributed significantly to the regression equation Results of the multivariate regression analyses are presented in Table 3 . Study 1 : Gender was the only variable that independently contributed significantly to the regression equation to predict lifting performance . The explained variance was 28 % . Both models to predict the other two outcome variables , static forward bend and dynamic forward bend , were non-significant . Study 2 : Gender and pain intensity -LRB- to a lesser extend -RRB- contributed significantly to the regression equation to predict lifting performances . The explained variance was 37 % . In the regression analysis to predict static forward bend performances , none of the independent variables contributed significantly to the regression equation -LRB- explained variance 27 % -RRB- . In the regression analysis to predict dynamic forward bending performances none of the independent variables contributed significantly to the regression equation . Collinearity diagnostics were performed for the independent variables . In both studies the average variance inflating factors -LRB- VIF -RRB- were greater than 1 , and none of the VIF-values were greater than 10 . Specifically , the relationship between pain intensity and measures of pain related fear were analyzed . In study 1 , the strength of the relation between pain and the TSK was r = − 0.04 -LRB- ns -RRB- . In study 2 , the strength of the relation between pain intensity and FABQ activity scale was r = 0.07 -LRB- ns -RRB- , and between pain intensity and FABQ work scale was r = 0.20 -LRB- ns -RRB- . Discussion This study has demonstrated that the associations between pain intensity and pain related fears on the one hand and FCE performances on the other hand were generally weak or non-significant . Correlations between pain intensity and pain related fears and performances were significant in only 7 out of 25 analyses -LRB- Table 2 -RRB- . The strength of these significant relationships ranged from r = − 0.23 to r = − 0.50 , explaining 5 to 25 % of the variance -LRB- r2 -RRB- . Multivariate regression analyses were non-significant in 3 out of 6 instances . When significant , pain intensity or pain related fear contributed little if any to these models . Relationships are consistent throughout the intensity spectra -LRB- upper quarter analyses and Fig. 1 -RRB- . Thus , overseeing all the results of this study , it appears that the relationships between pain and pain related fear and performances in an FCE are generally weak or non-existent . Although we realize that interpretations of these results are open for discussion , we interpret the magnitude of the relationships between pain and pain related fears on the one hand and performances in an FCE on the other hand of limited clinical relevance . In comparison to our previous study -LSB- 12 -RSB- , we have now used two new cohorts , two questionnaires instead of one to measure a wider range of pain related fears , and three performance tests instead of one to measure a wider range of avoidance behaviors . Additionally , we have added heart rate and observations as indices for effort level in lifting . Both pain intensity and pain related fear were poorly associated with indices for effort , explaining 7 % or less of the variance . The results of the 2 new studies presented here are generally consistent with our previous study , which adds to the robustness of the results . There may be several explanations for the weakness or non-existence of the associations between pain intensity and pain related fears on the one hand , and avoidance behaviors on the other hand . Pain intensity and pain related fears might have been inappropriately operationally defined by the NRS , the TSK and the FABQ , avoidance behavior might have been inappropriately operationally defined by the three performance measures , our study samples differ from samples reported elsewhere , or the variables were appropriately operationally defined , but the relationship was mediated by one or more currently unknown variables . Additionally , a combination of the above may explain our findings . The NRS , TSK and the FABQ may be considered among the standards to measure pain intensity and pain related fears . The reliability and the validity of the measures for avoidance behavior and pain related fears have been established . Both the performance measure ` heavy lifting ' and a postural tolerance test have been used previously in different studies as measures for avoidance behavior -LSB- 8 , 9 , 12 -RSB- . The activities selected are potentially harmful for patients with CLBP -LSB- 20 -RSB- . Thus , it seems unlikely that the operational definitions were inappropriate for the constructs measured . Both our study samples are similar to samples reported in other studies reporting on patients with CLBP concerning age , pain intensity , self-reported disability , and amount of fear avoidance beliefs -LSB- 8 , 10 -RSB- . This similarity may rule out the plausibility the results of our study are caused by the selection of study samples . While the TSK and the FABQ may be considered among the consented standards to measure pain related fears , it may be possible that the domain measured might be too large and general to be of value in predicting specific behaviors such as the ones used in this study . This in itself could explain the findings of this study and the lack of consistent findings in previous research . However , if the measures are considered valid representations of the constructs pain intensity , pain related fear , and avoidance behavior , then a different explanation should be considered for our findings . Other variables may serve as a mediator between pain variables and avoidance behavior . As suggested in recent pain literature , two variables should be considered as mediators or confounders : motivation -LSB- 29 -RSB- and acceptance -LSB- 30 -RSB- . Within the motivational models -LSB- 29 , 31 , 32 -RSB- , it is suggested that the value of the goal and the patient 's belief in his ability -LRB- self-efficacy -RRB- to attain this goal is predictive for his behavior . When applied to the results of this study , patients were apparently willing to perform the tests regardless of their pain related fears . They were willing to perform , because they may have been convinced that this would have helped them to reach a valued goal -LRB- for example return to work -RRB- . Contrarily , patients without pain related fears may perform poorly on the tests , because they do not see it to be of any value . Alternatively , a poor performance could be explained if the patient 's goal would be to use the test results for financial gain -LRB- disability allowance -RRB- -LSB- 33 -RSB- . In that case , pain related fears would be of little importance to determine a patient 's behavior . Within the acceptance model -LSB- 30 -RSB- , it is suggested that patients may be able to accept their pain or fears as an inevitable part of their lives . Patients would report pain or have cognitions such as pain related fears , but are able to function normally with their pain or fears . Some empirical evidence is found to support the applicability of this model within chronic pain -LSB- 34 , 35 -RSB- . If a mediating effect or confounding of one or more different variables is present , then poor or non-existent associations between pain intensity , pain related fears and test performance are very well imaginable . Future studies should be conducted to find empirical evidence for the proposition that constructs as motivation and acceptance are more important predictors for functional capacity than pain or pain related fears . Additionally , other currently unknown variables may have played a mediating role in the relationship between pain variables and avoidance behaviors . Both self-report and performance measures assess effort-related performance -LSB- 36 -RSB- . As such , they can not be defined independently of the person 's behavior . Pain-related disability is a matter of human performance , whether it is observed/measured or reported -LSB- 36 -RSB- and this may also apply to patient 's behavior in an admission phase of a rehabilitation program . In this stage patients need not only reveal their cognitions and perception of disability , but at the same time present an image to the practitioner -LSB- 37 -RSB- , to justify the need for treatment -LSB- 38 , 39 -RSB- and perhaps to justify the fact that they are off work due to CLBP . The scores on the questionnaires may thus be an overrating of the ` real ' pain or pain related fears . An FCE is a measure of demonstrated ability . Pain behaviors may prevent the patients to perform to their maximal physical capacity . The ratings of effort level indicate a sub maximal performance , suggesting that this behavior has occurred in study 2 -LRB- and probably also in study 1 , but data were unavailable -RRB- . Without these pain behaviors , the FCE results might have been higher . On average , the performance-based scores presented in this study may be considered an underrating of the physical abilities of the patients . Consequently , clinical interpretation of the outcomes of effort related assessments should be made with care . We propose that the scores on the questionnaires are interpreted as ` the patient reports that ... -LRB- he is fearful -RRB- , instead of ` the patient is/feels/perceives ... -LRB- fearful/fear -RRB- . For the FCE , we propose that the scores are interpreted as the patient 's performance , instead of the patient 's capacity -LRB- FPE : Functional Performance Evaluation -RRB- . The performance of a patient depends on his capacity and his willingness to produce -LSB- 25 -RSB- . The current study and our previous study show that report of pain and pain related fears explain little of the patient 's performances during FCE . Statements that ` a valid assessment of functional capacity can not be carried out without controlling for fear avoidance beliefs -LSB- 8 -RSB- and ` pain related fear is more disabling than pain itself ’10 are not supported by the results of this study . The results of this study may not be generalizable to other FCEs or other groups of patients . From the results of the current study it should be concluded that future research aimed at unrevealing ` determinants of performance ' in chronic pain should not be restricted to pain and pain related fears only , but include other avenues such as self efficacy -LSB- 40 , 41 -RSB- , motivation and acceptance as well .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

rehabilitation
lifting
tampa scale for kinesiophobia
fear avoidance beliefs questionnaire