Temporal relationships between pain, functioning, and human assumed central sensitization in patients with chronic low back pain; a single-case design

BACKGROUND

Interdisciplinary pain rehabilitation (IPR) aims to improve functioning in people with chronic low back pain (CLBP), and is not primary aimed at pain reduction. Many patients however also report a decrease in pain. An explanation could be that IPR results in a decrease in Central Sensitization (CS). As CS is not directly assessable in humans the term Human Assumed Central Sensitization (HACS) is used in this study. It is unknown whether a decrease in HACS precedes a decrease in pain and improved functioning or vice versa.

OBJECTIVES

This study aimed to gain understanding into the temporal relationships between changes in pain, functioning, and HACS in patients with CLBP during IPR.

DESIGN

Longitudinal observational small-N-study.

METHOD

Twelve patients filled in frequently repeated self-reports 1 week before, during the 12-week IPR program, and 2 weeks after IPR. Pain was assessed by Visual Analogue Scale for pain (daily), functioning by Pain Disability Index (weekly) and Work Ability Score (daily), and HACS by Central Sensitization Inventory part A (bi-weekly). Analyses were performed by visual inspection and time series cross-correlation analyses.

RESULTS

Visual inspection showed large fluctuations within and between individual participants in patterns over time. Cross-correlation analyses showed that in most participants, relationships between pain, functioning, and HACS were strongest when analyzed at the same time (55% of comparisons). Strength and direction of (strongest) correlations showed high interindividual variability (neg: 0.33-0.97; pos: 0.22-0.99).

CONCLUSION

Overall, relationships between pain, functioning, and HACS did not show consistent temporality in patients with CLBP.

Insufficient Evidence for Load as the Primary Cause of Nonspecific (Chronic) Low Back Pain. A Scoping Review

OBJECTIVE: To assess the causal role of the relationship between loading and the onset of nonspecific low back pain (NSLBP) and persistence of NSLBP (chronic low back pain [CLBP]). DESIGN: Scoping review. LITERATURE SEARCH: We searched the literature from 2010 until May 2021 using a combination of terms related to (spinal) load and the Bradford-Hill (BH) criteria. STUDY SELECTION CRITERIA: Operational definitions were developed for every criterion of the BH framework for causality. Study selection was based on the causal role of load in the onset of NSLBP and persistence of chronic low back pain. DATA SYNTHESIS: The BH criteria were operationalized, and causation was considered established when evidence supported the BH criteria strength, temporality, biological gradient, experiment, and biological plausibility. RESULTS: Twenty-two studies were included. There was no consistent support for an association between load and the incidence of NSLBP, or that more load increased the risk of NSLBP/CLBP. Half of the studies did not support specific load exposures to increase incidence of or increase pain in NSLBP/CLBP. Half of studies did not support load preceding NSLBP. No study supported plausible biological explanations to influence the relationship between load and NSLBP/CLBP, or that similar causes have similar effects on NSLBP. Nine of 10 experimental studies did not support that load results in NSLBP or that relieving load reduces NSLBP/CLBP. CONCLUSION: There was insufficient evidence to support a causal relationship between loading and the onset and persistence of NSLBP/CLBP based on the BH criteria. These results question the role of load management as the only/primary strategy to prevent onset and persistence of NSLBP/CLBP. J Orthop Sports Phys Ther 2024;54(3):1-15. Epub 25 January 2024. doi:10.2519/jospt.2024.11314.

Side-effects and adverse events of a shoulder- and back-support exoskeleton in workers: A systematic review

INTRODUCTION

While the biomechanical effects of exoskeletons are well studied, research about potential side-effects and adverse events are limited. The aim of this systematic review was to provide an overview of the side-effects and adverse events on shoulder- and back-support exoskeletons during work tasks.

METHODS

Four in-field studies and 32 laboratory studies were included in this review, reporting on n = 18 shoulder exoskeletons, n = 9 back exoskeletons, n = 1 full body with a supernumerary arm, and n = 1 combination of shoulder and back exoskeleton.

RESULTS

The most frequent side-effect reported is discomfort (n = 30), followed by a limited usability of the exoskeleton (n = 16). Other identified side-effects and adverse events were changes in muscle activity, mobility, task performance, balance and posture, neurovascular supply, gait parameters and precision. An incorrect fit of the exoskeleton and the decreased degrees of freedom are most often reported as causes of these side-effects. Two studies did not find any side-effects. This review also showed that there are differences in the occurrence of side-effects in gender, age, and physical fitness. Most studies (89%) were conducted in a laboratory setting. Most studies (97%) measured short-term effects only. Psychological and social side-effects or adverse events were not reported. Side-effects and adverse events for active exoskeletons were understudied (n = 4).

CONCLUSION

It was concluded that the evidence for side-effects and adverse events is limited. If available, it mainly consists of reports of mild discomfort and limited usability. Generalisation is limited because studies were conducted in lab settings and measured short term only, and most participants were young male workers.

Personality traits are not associated with changes in employment status over 3 years in persons with multiple sclerosis

Previous research discovered a protective effect of higher conscientiousness against a 3-year deterioration in employment status in persons with multiple sclerosis (pwMS). To replicate these findings, we used data from a multicentre prospective cohort study where 145 employed pwMS completed questionnaires, neurological and neuropsychological examinations at baseline and after 3 years. A 3-year deterioration in employment status was reported in 31.0%. We observed no differences in personality, demographics or clinical characteristics between pwMS with deteriorated or stable employment status. These null findings may be partly explained by the classification of deteriorated employment status, which does not reflect Dutch labour conditions.

Self-regulation as rehabilitation outcome: what is important according to former patients?

PURPOSE

Self-regulation refers to self-management and self-control, with or without disability. Outcomes of rehabilitation with respect to self-regulation are unclear. This study aims to identify elements of self-regulation that former patients consider important in the context of medical rehabilitation.

MATERIALS AND METHODS

Qualitative exploration based on focus group discussions (FGDs). Transcripts were analysed using thematic analysis as well as open coding. Forty individuals participated in seven diagnosis-related FGDs.

RESULTS

Six subthemes were raised in the FGDs which could be merged into three main themes. Two main themes are conditional for regaining self-regulation: 1) having insight into one's condition and abilities (i.e., insight into impairments. consequences of impairments. abilities); 2) to know how to cope with the consequences of the condition (be able to communicate limitations; have to trust in body and functioning). The subject of the last theme 3) is how to apply self-regulation in one's own life (to make use of abilities and optimize functioning).

CONCLUSIONS

Three main themes of self-regulation in the context of medical rehabilitation were identified by former patients, partly relating to the ability to self-regulate and partly to the execution of self-regulation. This knowledge can be used to define specific rehabilitation goals and further develop rehabilitation outcome measurement.IMPLICATIONS FOR REHABILITATIONAwareness of the fundamental subthemes of self-regulation in rehabilitation will positively contribute to theory building and improve clinical practice (e.g., goal setting).Paying explicit attention to the six subthemes as standard elements of rehabilitation will help to provide a comprehensive view concerning self-regulation.The conceptual model of self-regulation, based on patient perspectives, can contribute to the measurement of rehabilitation outcomes.

Work difficulties in people with multiple sclerosis: The role of anxiety, depression and coping

Background

Symptoms of anxiety and depression affect the daily life of people with multiple sclerosis (MS). This study examined work difficulties and their relationship with anxiety, depression and coping style in people with MS.

Methods

219 employed people with MS (median age  =  43 years, 79% female) completed questionnaires on anxiety, depression, coping style, demographics and work difficulties, and underwent a neurological examination. Two regression analyses were performed with work difficulties as the dependent variable and either anxiety or depression as continuous independent variables. Coping style, age, gender, educational level, MS-related disability and disease duration were added as additional predictors, as well as interaction terms between coping style and either symptoms of depression or anxiety.

Results

A significant model was found (F_(10,205)  =  13.14, p < 0.001, R²  =  0.39) in which anxiety, emotion- and avoidance-oriented coping and MS-related disability were positively related to work difficulties. The analysis of depression resulted in a significant model (F_(10,205)  =  14.98, p < 0.001, R²  =  0.42) in which depression, emotion- and avoidance-oriented coping and MS-related disability were positively related to work difficulties. None of the interaction effects were significant.

Conclusions

Work difficulties were positively related to anxiety, depression, emotion- and avoidance-oriented coping and MS-related disability in workers with MS.

Measurement Properties of the Work Ability Score in Sick-Listed Workers with Chronic Musculoskeletal Pain

Purpose Chronic musculoskeletal pain can have a major impact on ability to work. The work ability score is a commonly used single-item question to assess work ability but has not been fully validated yet. The aim of the present study was to evaluate test-retest reliability, agreement, construct validity, and responsiveness of the work ability score among sick-listed workers with chronic musculoskeletal pain. Methods Data of sick-listed workers with chronic musculoskeletal pain was routinely collected at seven rehabilitation centres in the Netherlands. Assessments included a set of questionnaires, administered at admission and discharge from a fifteen-week vocational rehabilitation program. Test-retest reliability was determined with the intraclass correlation coefficient. For agreement, the standard error of measurement and smallest detectable changes were calculated. Construct validity was assessed by testing hypotheses regarding Spearman rank correlation coefficient. Area under the curve obtained from the receiver operating characteristic curve and minimal clinically important change were determined for the total sample and work ability score baseline tertile groups to assess responsiveness. Results In total, 34 workers were analyzed for reliability and agreement, 1291 workers for construct validity, and 590 responded to the responsiveness questionnaire. Reliability reached an intraclass correlation coefficient of 0.89; 95% CI 0.77-0.94, a standard error of measurement of 0.69 points, and the smallest detectable change of 1.92 points. For construct validity, six of the seven predefined hypotheses were not refuted. The area under the curve was 0.76 (95% CI 0.71-0.81) allowing for discrimination between stable and improved workers, with a minimal clinically important change of 2.0 points for the total sample. Conclusion The work ability score showed good measurement properties among sick-listed workers with chronic musculoskeletal pain.

Maximal cardiopulmonary exercise test in patients with chronic low back pain: feasibility, tolerance and relation with central sensitization. An observational study

PURPOSE

To analyze the feasibility of and pain-related tolerance to a maximal cardiopulmonary exercise test (CPET), and the relationship between the aerobic capacity and central sensitization (CS) in patients with chronic low back pain (CLBP).

METHODS

An observational study, combining a cross-sectional and a prospective 24-hour follow-up was performed. Participants underwent a maximal CPET on a cycle ergometer and were assessed with three measures of CS (CS Inventory, quantitative sensory testing and heart rate variability). Before the CPET, immediately afterwards and 24 h after, the Pain Response Questionnaire (PRQ) was filled out. The CPET was considered feasible when >80% performed maximally, and tolerable when <20% reported relevant pain increase, body reactions and additional pain medication use in the PRQ. Multiple regression analyses were applied to assess the relationship between the aerobic capacity (VO2max) and CS measures, corrected for confounders.

RESULTS

74 patients with CLBP participated of which 30 were male, mean age was 40.4 years (SD: 12.4) and median VO2max was 23.9 ml/kg/min (IQR: 18.2-29.4). CPET was completed by 92%. No serious adverse events occurred. A relevant pain increase was reported in the upper legs by 40% immediately after CPET and by 28% 24 h afterwards, 27% reported body reactions after 24 h, and 22% increased pain medication use 24 h after CPET. Very weak and not significant relations (r_partial=-0.21 to 0.05; p > 0.10) were observed between aerobic capacity and CS measures.

CONCLUSIONS

A maximal CPET is feasible in patients with CLBP. Most, but not all, tolerated it well. CS was not related to aerobic capacity.Implications for rehabilitationMaximal CPET is feasible in patients with CLBP and well tolerated by most patients.Maximal CPET can be safely applied to assess the aerobic capacity of patients with CLBP.Aerobic capacity is unrelated to central sensitization.Outcomes of a maximal CPET and the pain response to straining activity can be used to provide valid information for the decision-making of exercise therapy.

Self-reported occupational functioning in persons with relapsing-remitting multiple sclerosis: Does personality matter?

BACKGROUND

Multiple sclerosis (MS) poses a major threat to sustainable employability. Identifying conditions and factors that promote work participation is of great importance. Our objective was to explore the contribution of personality traits in explaining occupational functioning in MS.

METHODS

241 participants with relapsing-remitting MS (78% female, median age: 42.0 years, median EDSS: 2.0) and 60 healthy controls (70% female, median age: 45.0 years) underwent neuropsychological and neurological examinations and completed questionnaires. Multivariate logistic and linear regression analyses were conducted to examine relations between personality traits and self-reported occupational functioning, while accounting for known correlates.

RESULTS

Personality traits were not associated with self-reported occupational functioning when correcting for known correlates. A higher impact of fatigue (B = -0.05, p = .005 and B = -0.04, p = .009) and depression (B = -0.22, p = .008 and B = -0.21, p = .01) were associated with no paid job (R² = 0.13) and considering to reduce work hours (R² = 0.12). A higher impact of fatigue (B = -0.05, p = .008, β = 0.46, p = .001 and β = -0.36, p = .001) was associated with absenteeism from work (R² = 0.15), more presenteeism (R² = 0.35) and lower work ability (R² = 0.25). A higher impact of fatigue (β = 0.46, p = .001) and anxiety (β = 0.25, p = .001) were associated with more work difficulties (R² = 0.54).

CONCLUSION

Personality traits did not explain additional variance in self-reported occupational functioning in persons with relapsing-remitting MS with mild disability. The impact of fatigue was the main and most consistent correlate of occupational functioning, often combined with depression or anxiety. Total explained variance of the models was limited, emphasizing the need to additionally examine other (contextual) factors when considering occupational challenges in MS.

Evaluation of a Wearable Non-Invasive Thermometer for Monitoring Ear Canal Temperature during Physically Demanding (Outdoor) Work

Aimed at preventing heat strain, health problems, and absenteeism among workers with physically demanding occupations, a continuous, accurate, non-invasive measuring system may help such workers monitor their body (core) temperature. The aim of this study is to evaluate the accuracy and explore the usability of the wearable non-invasive Cosinuss° °Temp thermometer. Ear canal temperature was monitored in 49 workers in real-life working conditions. After individual correction, the results of the laboratory and field study revealed high correlations compared to ear canal infrared thermometry for hospital use. After performance of the real-life working tasks, this correlation was found to be moderate. It was also observed that the ambient environmental outdoor conditions and personal protective clothing influenced the accuracy and resulted in unrealistic ear canal temperature outliers. It was found that the Cosinuss° °Temp thermometer did not result in significant interference during work. Therefore, it was concluded that, without a correction factor, the Cosinuss° °Temp thermometer is inaccurate. Nevertheless, with a correction factor, the reliability of this wearable ear canal thermometer was confirmed at rest, but not in outdoor working conditions or while wearing a helmet or hearing protection equipment.

Can breathing gases be analyzed without a mouth mask? Proof-of-concept and concurrent validity of a newly developed design with a mask-less headset

A portable headset has been developed to analyze breathing gases and establish the energetic workload of physically active workers. This proof-of-concept study aimed to investigate the following: (1) the validity of the headset compared to indirect calorimetry using a mouth mask; (2) the validity of the headset compared to the validity of oxygen consumption (V̇O2) estimated on the basis of heart rate; (3) the influence of wind on validity; and (4) user experiences of the headset. Fifteen subjects performed a submaximal cycling test twice, once with the headset, and once with a mouth mask and heartrate monitor. Concurrent validity of the headset was analyzed using an intraclass correlation coefficient (ICC). Across all phases, a good correlation between the headset and mouth mask was observed for V̇O2, carbon dioxide production (V̇CO2) and exhaled volume (V̇E) (ICC≥0.72). The headset tended to underestimate V̇O2, V̇CO2 and V̇E at low intensities and to overestimate it at higher intensities. The headset was more valid for estimating V̇O2 (ICC = 0.39) than estimates based on heart rate (ICC = 0.11) (n = 7). Wind flow caused an overestimation (md ≥ 18.4 ± 16.9%) and lowered the correlation of V̇O2 between the headset and the mouth mask to a moderate level (ICC = 0.48). The subjects preferred the headset over the mouth mask because it was more comfortable, did not hinder communication and had lower breathing resistance. The headset appears to be useable for monitoring development of the energetic workloads of physically active workers, being more valid than heart rate monitoring and more practical than indirect calorimetry with a mouth mask. Proof-of-concept was confirmed. Another design step and further validation studies are needed before implementation in the workplace.

Functional Capacity Evaluation Research: Report from the Fourth International Functional Capacity Evaluation Research Meeting

Purpose To summarize progress of functional capacity evaluation (FCE) research based on the proceedings of the Fourth International FCE Research Conference held in Switzerland on September 21 and 22, 2018. Methods A scientific committee identified key issues in FCE research and developed the program including key note presentations, a call for abstracts, and round table discussions over 2 days. Highlights of the presentations and discussions are summarized in this article. Results Seventy-nine participants from 11 countries attended the conference where 10 keynote lectures and 21 abstracts were presented. There was also an open discussion regarding the need for an International FCE clinical practice guideline (CPG), methods for developing such a guideline, and practical next steps. Full program details and abstracts from this Fourth International FCE Research Conference are available from https://www.sar-reha.ch/interessengemeinschaften/ig-ergonomie.html . Conclusions Researchers and clinicians continue to increase the body of knowledge in the FCE field. A major finding of this conference is the diversity across the different FCE protocols and research groups as well as of the different uses of FCE across cultural and social economic systems. Next steps will include exploring the development of an international, interdisciplinary, evidence-based FCE clinical practice guideline by a committee formed at the conference.

Early termination in interdisciplinary pain rehabilitation: numbers, timing, and reasons. A mixed method study

PURPOSE

To analyse the number of, timing of, and reasons for early termination of interdisciplinary pain rehabilitation (IPR).

METHODS

A multicentre study in two Dutch rehabilitation centres with a mixed method design. Quantitative part: retrospective patient file review of all IPR patients. Qualitative part: 20 semi-structured patient interviews with early IPR terminators.

RESULTS

One hundred and thirty-seven of 428 participants (31.3%) had terminated IPR early, of which almost 30% had a positive reason. Of a planned treatment duration of 12 weeks, the median (interquartile range (IQR)) reduction was 5.3 week (3.0; 8.0). Over 80% of the early terminators with negative reasons stopped in the first half of IPR, whereas approximately 55% of the early terminators with positive reasons stopped in the final quarter of IPR. A discrepancy between patient expectations of the aim and content and the actual IPR was mentioned as a negative reason for early termination. Many of the positive early terminators were able to self-manage.

CONCLUSIONS

Previously reported figures on early termination were confirmed. Early termination of IPR should not be considered negative per se, because a substantial proportion of early terminations have a positive reason. Negative early terminators tend to stop earlier during IPR, compared to positive terminators.Implications for rehabilitationSubstantial rates of patients (31%) terminate interdisciplinary pain rehabilitation (IPR) earlier than planned.Early IPR termination should not be considered negative per se, because a substantial proportion of early terminations have a positive reason (i.e. goals achieved early).Although patients receive extensive personalised information about aim and content of IPR before starting, early terminators with a negative reason often have different expectations about the aim and content of treatment.Clinicians and researchers should be focused on how to explain IPR to the patient and check whether the patient has understood it well and is convinced of its credibility.

Monitoring core temperature of firefighters to validate a wearable non-invasive core thermometer in different types of protective clothing: Concurrent in-vivo validation

This study aims (1) to test the validity of a new non-invasive core thermometer, Cosinuss°, in rest and (2) during firefighting simulation tasks, against invasive temperature pill and inner-ear temperature and (3) to compare the change in core temperature of firefighters when working in two types of protective clothing (traditional turnout gear versus new concept). 11 active firefighters performed twice a selection of tasks during their periodic preventive medical examination and a fire-extinguishing task. Without correction no correlation between the Cosinuss° and thermometer pill (ICC≤0.09, p ≥ 0.154, LoA≥1.37) and a moderate correlation between Cosinuss° and inner-ear infrared (ICC = 0.40, p = 0.044, LoA±1.20) was observed. With individual correction both correlations were excellent (ICC≥0.84, p = 0.000, LoA≤0.30). However, during and after working all correlations were poor and non-significant (ICC≤0.38, p ≥ 0.091, LoA≥1.71). During firefighting tasks, the Cosinuss° is invalid for measuring the core temperature. No differences in heat development in the two types of protective clothing was proven.

Trajectories of Physical Work Capacity in Early Symptomatic Osteoarthritis of Hip and Knee: Results from the Cohort Hip and Cohort Knee (CHECK) Study

Purpose To evaluate the 5-year course of physical work capacity of participants with early symptomatic osteoarthritis (OA) of the hip and/or the knee; to identify trajectories and explore the relationship between trajectories and covariates. Methods In a prospective cohort study, physical work capacity was measured at baseline, using a test protocol (functional capacity evaluation) consisting of work-related physical activities. Participants were invited to participate in 1, 2 and 5 year follow-up measurements. Multilevel analysis and latent classes analysis were performed, in models with test performances as dependent variables and age, sex, work status, self-reported function (Western Ontario McMasters Arthritis Scale-WOMAC), body mass index (BMI) and time as independent variables. Multiple imputation was used to control for the influence of missing data. Results At baseline and after 1, 2 and 5 years there were 96, 64, 61 and 35 participants. Mean (SD) age at baseline was 56 (4.9) years, 84% were females. There was no statistically significant change in test performances (lifting low and high, carrying, static overhead work, repetitive bending, repetitive rotations) between the 4 measurements. Male sex, younger age and better self-reported function were statistically significant (p < 0.05) determinants of higher performance on most of the tests; having a paid job, BMI and progression of time were not. Three trajectories were identified: 'weak giving way', 'stable and able', and 'strong with decline'. Discussion In subgroups of participants with early symptomatic OA, determined by age, sex and self-reported function, physical work capacity seems to be a stable characteristic over 5 years.

Repeatability and Safety of the Functional Capacity Evaluation-One-Handed for Individuals with Upper Limb Reduction Deficiency and Amputation

Purpose To assess repeatability and safety of the functional capacity evaluation-one-handed (FCE-OH), a FCE-OH individuals, consisting of eight items. Method The FCE-OH protocol was administered twice to 23 individuals with upper limb absence (87% male; median age 46 years; median 2 days between sessions). To examine repeatability, test-retest reliability and agreement were assessed with the intraclass correlations coefficient (ICC) and limits of agreement (LoA), respectively. Reliability was considered acceptable when ICC-values were ≥0.75. Widths of LoA of four tests were compared with those of healthy adults. Safety and pain response were assessed with a questionnaire. Results After controlling for stability of construct, ICC-values ranged between 0.23 and 0.96, and widths of LoA ranged between 16 and 79%. Intertrial (learning) effects were present in three test items. No serious adverse reactions were reported. A pain response was reported by 30% of the participants. Conclusion Good or excellent reliability was observed in five tests, while three items showed poor or moderate test-retest reliability. Interpretation of agreement was possible for four tests, of which three showed widths of LoA similar to those reported in healthy adults. Learning effects were present; therefore, interpretation at the individual level should be performed with care. As the CI of several items were wide, confirmation of results in a larger sample is warranted. Safety was confirmed.

The capability set for work - correlates of sustainable employability in workers with multiple sclerosis

Background

The aim of this study was to examine whether work capabilities differ between workers with Multiple Sclerosis (MS) and workers from the general population. The second aim was to investigate whether the capability set was related to work and health outcomes.

Methods

A total of 163 workers with MS from the MS@Work study and 163 workers from the general population were matched for gender, age, educational level and working hours. All participants completed online questionnaires on demographics, health and work functioning. The Capability Set for Work Questionnaire was used to explore whether a set of seven work values is considered valuable (A), is enabled in the work context (B), and can be achieved by the individual (C). When all three criteria are met a work value can be considered part of the individual’s ‘capability set’.

Results

Group differences and relationships with work and health outcomes were examined. Despite lower physical work functioning (U = 4250, p = 0.001), lower work ability (U = 10591, p = 0.006) and worse self-reported health (U = 9091, p ≤ 0.001) workers with MS had a larger capability set (U = 9649, p ≤ 0.001) than the general population. In workers with MS, a larger capability set was associated with better flexible work functioning (r = 0.30), work ability (r = 0.25), self-rated health (r = 0.25); and with less absenteeism (r = − 0.26), presenteeism (r = − 0.31), cognitive/neuropsychiatric impairment (r = − 0.35), depression (r = − 0.43), anxiety (r = − 0.31) and fatigue (r = − 0.34).

Conclusions

Workers with MS have a larger capability set than workers from the general population. In workers with MS a larger capability set was associated with better work and health outcomes.

Trial registration

This observational study is registered under NL43098.008.12: ‘Voorspellers van arbeidsparticipatie bij mensen met relapsing-remitting Multiple Sclerose’. The study is registered at the Dutch CCMO register (https://www.toetsingonline.nl). This study is approved by the METC Brabant, 12 February 2014. First participants are enrolled 1^st of March 2014.

Functional Capacity Evaluation Research: Report from the Third International Functional Capacity Evaluation Research Meeting

Purpose Based on the success of the first two conferences the Third International FCE Research Conference was held in The Netherlands on September 29, 2016. The aim was to provide ongoing opportunity to share and recent FCE research and discuss its implications. Methods Invitations and call for abstracts were sent to previous attendees, researchers, practicing FCE clinicians and professionals. Fifteen abstracts were selected for presentation. The FCE research conference contained two keynote lectures. Results 54 participants from 12 countries attended the conference where 15 research projects and 2 keynote lectures were presented. The conference provided an opportunity to present and discuss recent FCE research, and provided a forum for discourse related to FCE use. Conference presentations covered aspects of practical issues in administration and interpretation; protocol reliability and validity; consideration of specific injury populations; and a focused discussion on proposed inclusion of work physiology principles in FCE testing with the Heart Rate Reserve Method. Details of this Third International FCE Research Conference are available from http://repro.rcnheliomare.nl/FCE.pdf . Conclusions Researchers, clinicians, and other professionals in the FCE area have a common desire to further improve the content and quality of FCE research and to collaborate to further develop research across systems, cultures and countries. A fourth, 2-day, International FCE research conference will be held in Valens, Switzerland in August or September 2018. A 'FCE research Society' will be developed.

Functional Capacity Evaluation in Upper Limb Reduction Deficiency and Amputation: Development and Pilot Testing

Purpose To develop and pilot test a functional capacity evaluation (FCE) for individuals with upper limb absence (ULA) due to reduction deficiency or amputation, and to examine the relationship between FCE results and presence of musculoskeletal complaints (MSC). Method Five tests (overhead lifting, overhead working, repetitive reaching, fingertip dexterity, and handgrip strength) were selected and adapted if necessary. The newly developed FCE, called FCE-One-Handed (FCE-OH), was pilot tested in 20 adults individuals with ULA, and 20 matched controls. MSC were assessed via a questionnaire. Results Adaptations were considered necessary for all tests, except the handgrip strength test. The repetitive overhead lifting test of the non-affected limb was added. On the overhead lifting test, individuals with above-elbow ULA (ten males), performed similar to controls using one hand. When lifting bimanually using the prosthesis, a trend for lower lifting capacity of individuals with below-elbow ULA (seven males, three females) was observed compared to controls. On the overhead working test, individuals with above-elbow ULA performed worse compared to controls. Other tests showed no significant differences between groups. Relationships between FCE results and presence of MSC were non-significant. Conclusion The FCE-OH can be used to test functional capacity of one-handed individuals. Individuals with ULA generally showed similar functional capacity as two-handed individuals. FCE results were not related to MSC. It was discussed that a higher physical load on the non-affected limb might reflect a relative deficit of functional capacity.

Can a smart chair improve the sitting behavior of office workers?

Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A 'smart' office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior. This study aimed to investigate the effect of the feedback signal on sitting behavior and musculoskeletal discomfort. In a 12-week prospective cohort study (ABCB design) among office workers (n = 45) was measured sitting duration and posture, feedback signals and musculoskeletal discomfort. Between the study phases, small changes were observed in mean sitting duration, posture and discomfort. After turning off the feedback signal, a slight increase in sitting duration was observed (10 min, p = 0.04), a slight decrease in optimally supported posture (2.8%, p < 0.01), and musculoskeletal discomfort (0.8, p < 0.01) was observed. We conclude that the 'smart' chair is able to monitor the sitting behavior, the feedback signal, however, led to small or insignificant changes.

Study protocol for a randomised controlled multicentre study: the Foraminotomy ACDF Cost-Effectiveness Trial (FACET) in patients with cervical radiculopathy

INTRODUCTION

Cervical radiculopathy due to discogenic or spondylotic stenosis of the neuroforamen can be surgically treated by an anterior discectomy with fusion (ACDF) or a posterior foraminotomy (FOR). Most surgeons prefer ACDF, although there are indications that FOR is as effective as ACDF, has a lower complication rate and is less expensive. A head-to-head comparison of the 2 surgical techniques in a randomised controlled trial has not yet been performed. The study objectives of the Foraminotomy ACDF Cost-Effectiveness Trial (FACET) study are to compare clinical outcomes, complication rates and cost-effectiveness of FOR to ACDF.

METHODS AND ANALYSIS

The FACET study is a prospective randomised controlled trial conducted in 7 medical centres in the Netherlands. The follow-up period is 2 years. The main inclusion criterion is a radiculopathy of the C4, C5, C6 or C7 nerve root, due to a single-level isolated cervical foraminal stenosis caused by a soft disc and/or osteophytic component, requiring operative decompression. A sample size of 308 patients is required to test the hypothesis of clinical non-inferiority of FOR versus ACDF. Primary outcomes are: 'operative success', the measured decrease in radiculopathy assessed by the visual analogue scale and 'patient success', assessed by the modified Odom's criteria. Secondary outcomes are: Work Ability Index (single-item WAI), quality of life (EuroQol 5 Dimensions 5 level Survey, EQ-5D-5L), Neck Disability Index (NDI) and complications. An economic evaluation will assess cost-effectiveness. In addition, a budget impact analysis will be performed.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Institutional Ethics Committee of the University Medical Center Groningen. Results of this study will be disseminated through national and international papers. The participants and relevant patient support groups will be informed about the results of the study.

TRIAL REGISTRATION NUMBER

NTR5536, pre-results.

Functional Capacity Evaluation Research: Report from the Second International Functional Capacity Evaluation Research Meeting

INTRODUCTION

Functional capacity evaluations are an important component of many occupational rehabilitation programs and can play a role in facilitating reintegration to work thus improving health and disability outcomes. The field of functional capacity evaluation (FCE) research has continued to develop over recent years, with growing evidence on the reliability, validity and clinical utility of FCE within different patient and healthy worker groups. The second International FCE Research Conference was held in Toronto, Canada on October 2nd 2014 adjacent to the 2014 Work Disability Prevention Integration conference. This paper describes the outcomes of the conference.

REPORT

Fifty-four participants from nine countries attended the conference where eleven research projects and three workshops were presented. The conference provided an opportunity to discuss FCE practice, present new research and provide a forum for discourse around the issues pertinent to FCE use. Conference presentations covered aspects of FCE use including the ICF-FCE interface, aspects of reliability and validity, consideration of specific injury populations, comparisons of FCE components and a lively debate on the merits of 'Man versus Machine' in FCE's.

FUTURE DIRECTIONS

Researchers, clinicians, and other professionals in the FCE area have a common desire to improve the content and quality of FCE research and to collaborate to further develop research across systems, cultures and countries.

Measurement Properties of the Spinal Function Sort in Patients with Sub-acute Whiplash-Associated Disorders

PURPOSE

To extensively analyze the measurement properties the Spinal Function Sort (SFS) in patients with sub-acute whiplash-associated disorders (WAD).

METHODS

Three-hundred-two patients with WAD were recruited from an outpatient work rehabilitation center. Internal consistency was assessed by Cronbach's α. Construct validity was tested based on eight a priori hypotheses. Structural validity was measured with principal component analysis (PCA). Test-retest reliability and agreement was evaluated in a sub sample (n = 32) using intraclass correlation coefficient (ICC) and limits of agreement (LoA). The predictive validity of SFS for future work status at 1, 3, 6, and 12 months follow-up was determined by area under the curve (AUC) of receiver operating characteristics. Non-return to work (N-RTW) was defined with two cut-off points: workcapacity <50 and <100 %.

RESULTS

N-RTW decreased from 50%, 1 month follow-up, to 14%, 12 months follow-up. Cronbach's α was 0.98, PCA revealed evidence for unidimensionality. ICC was 0.86, LoA was ±33 points. Seven out of eight hypotheses for construct validity were not rejected. AUC reduced with a longer follow-up from 0.71 for 1 month to 0.61 at 12 months, for cut-off point <50%. For cut-off point <100% these values were 0.71 and 0.59.

CONCLUSION

In patients with sub-acute WAD test-retest reliability, internal consistency, construct- and structural validity of the SFS were adequate. LoA were substantial. Sensitivity to accurately predict N-RTW was poor. The predictive validity of the SFS for N-RTW of patients with sub-acute WAD from an outpatient work rehabilitation setting was only sufficient for the short term (1 month).

Construct Validity of Functional Capacity Evaluation in Patients with Whiplash-Associated Disorders

PURPOSE

The construct validity of functional capacity evaluations (FCE) in whiplash-associated disorders (WAD) is unknown. The aim of this study was to analyse the validity of FCE in patients with WAD with cultural differences within a workers' compensation setting.

METHODS

314 participants (42% females, mean age 36.7 years) with WAD (grade I and II) were referred for an interdisciplinary assessment that included FCE tests. Four FCE tests (hand grip strength, lifting waist to overhead, overhead working, and repetitive reaching) and a number of concurrent variables such as self-reported pain, capacity, disability, and psychological distress were measured. To test construct validity, 29 a priori formulated hypotheses were tested, 4 related to gender differences, 20 related associations with other constructs, 5 related to cultural differences.

RESULTS

Men had significantly more hand grip strength (+17.5 kg) and lifted more weight (+3.7 kg): two out of four gender-related hypotheses were confirmed. Correlation between FCE and pain ranged from -0.39 to 0.31; FCE and self-reported capacity from -0.42 to 0.61; FCE and disability from -0.45 to 0.34; FCE and anxiety from -0.36 to 0.27; and FCE and depression from -0.41 to 0.34: 16 of 20 hypotheses regarding FCE and other constructs were confirmed. FCE test results between the cultural groups differed significantly (4 hypotheses confirmed) and effect size (ES) between correlations were small (1 hypothesis confirmed). In total 23 out of 29 hypotheses were confirmed (79%).

CONCLUSIONS

The construct validity for testing functional capacity was confirmed for the majority of FCE tests in patients with WAD with cultural differences and in a workers' compensation setting. Additional validation studies in other settings are needed for verification.

Reliability of clinician rated physical effort determination during functional capacity evaluation in patients with chronic musculoskeletal pain

INTRODUCTION

Functional capacity evaluation (FCE) can be used to make clinical decisions regarding fitness-for-work. During FCE the evaluator attempts to assess the amount of physical effort of the patient. The aim of this study is to analyze the reliability of physical effort determination using observational criteria during FCE.

METHODS

Twenty-one raters assessed physical effort in 18 video-recorded FCE tests independently on two occasions, 10 months apart. Physical effort was rated on a categorical four-point physical effort determination scale (PED) based on the Isernhagen criteria, and a dichotomous submaximal effort determination scale (SED). Cohen's Kappa, squared weighted Kappa and % agreement were calculated.

RESULTS

Kappa values for intra-rater reliability of PED and SED for all FCE tests were 0.49 and 0.68 respectively. Kappa values for inter-rater reliability of PED for all FCE tests in the first and the second session were 0.51, and 0.72, and for SED Kappa values were 0.68 and 0.77 respectively. The inter-rater reliability of PED ranged from κ = 0.02 to κ = 0.99 between FCE tests. Acceptable reliability scores (κ > 0.60, agreement ≥80 %) for each FCE test were observed in 38 % of scores for PED and 67 % for SED. On average material handling tests had a higher reliability than postural tolerance and ambulatory tests.

CONCLUSION

Dichotomous ratings of submaximal effort are more reliable than categorical criteria to determine physical effort in FCE tests. Regular education and training may improve the reliability of observational criteria for effort determination.

Towards a comprehensive Functional Capacity Evaluation for hand function

The aim of this study was to develop a more efficient (i.e. shortened) protocol for hand function capacity evaluation and to test the agreement of the protocol compared to the original protocol. 643 Healthy subjects performed tests for hand function. Agreement between two shortened protocols was compared with an existing protocol. The original protocol was performed once and the proposed shortened protocol differed in the number of trials which were reduced by statistical elimination. Agreement was determined with Intraclass Correlation Coefficients (ICC) and Limits of Agreement (LoA). Excellent ICCs (≥0.91) were observed in all proposed protocols except for the one trial purdue pegboard test protocol. For all tests of hand function, shorter protocols are valid to determine hand function. For Tip Pinch Strength testing, Palmar Pinch Strength testing and the Purdue Pegboard test, a two-trial protocol is recommended, because the LoA were considerable, which could affect decision-making with regards to hand capacity. For the Hand Grip strength test, the Key Pinch Strength test and the Complete Minnesota Dexterity Test, a one-trial protocol is recommended, because the LoA were acceptable. It was concluded that for healthy subjects, this shorter protocol is a reliable measure. Further testing of the short form hand FCE protocols should be completed on patients with disabling conditions prior to widespread use of these protocols among clinical samples.

Towards an ICF- and IMMPACT-based pain vocational rehabilitation core set in the Netherlands

BACKGROUND

For clinical use and research of pain within the context of vocational rehabilitation, a specific core set of measurements is needed. The recommendations of the International Classification of Functioning, Disability and Health (ICF) brief Core Set for Vocational Rehabilitation (VR) and those of Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) cover two broad areas. These two sources can be integrated when made applicable to vocational rehabilitation and pain. Objective To develop a core set of diagnostic and evaluative measures specifically for vocational rehabilitation of patients with subacute and chronic musculoskeletal pain, while using the brief ICF core set for VR as the reference framework in VR, and the IMMPACT recommendations in the outcome measurements around pain.

METHODS

Three main steps were taken. The first step was to remove irrelevant and duplicate domains of the brief ICF Core Set for Vocational Rehabilitation and the IMMPACT recommendations around pain. The second step was to match the remaining domains with existing instruments or measures. Instruments were proposed based on availability and its proven use in Dutch practice and based on proof of sufficient clinimetric properties. In step 3, the preliminary VR-Pain core set was presented to 3 expert panels: proposed users, Dutch pain rehabilitation experts, and international VR experts.

RESULTS

Experts agreed with the majority of the proposed domains and instruments. The final VR-Pain Core Set consists of 18 domains measured with 12 instruments. All instruments possessed basic clinimetric properties.

CONCLUSION

An agreed-upon VR-Pain Core Set with content that covers relevant domains for pain and VR and validated instruments measuring these domains has been developed. The VR-Pain Core Set may be used for regular clinical purposes and research in the field of vocational rehabilitation and pain, but adaptations should be considered for use outside the Netherlands.

Developing research on performance-based functional work assessment: report on the first international functional capacity evaluation research meeting

INTRODUCTION

Research on Performance-Based Work Assessment, also known as Functional Capacity Evaluation (FCE), has evolved substantially over the past decades. Although this field of research has developed, the use of FCE has been an object of discussion and debate internationally. Unfortunately, there has been no platform or infrastructure available for FCE researchers to present their research, discuss, and collaborate.

METHODS

An International FCE Research Meeting was held in Haren, The Netherlands on October 25, 2012, with 48 participants from eight countries. The meeting consisted of presentation of new research, two debates, and an open discussion that aimed at creating an overview of gaps in research as identified by the participants.

RESULTS

The discussion resulted in the identification of 17 research needs, which are listed in this paper. Important categories were: further validation of FCE across settings, jurisdictions and patient groups; additional impact and cost-effectiveness evaluation of FCE compared to alternatives; and the use of ICF as guiding framework.

CONCLUSION

Researchers, clinicians, and other professionals in the FCE area are interested in improving the quality and content of FCE research by setting a common set of priorities and creating an international peer network.

Reliability and safety of functional capacity evaluation in patients with whiplash associated disorders

INTRODUCTION

Whiplash-associated disorders (WAD) are a burden for both individuals and society. It is recommended to evaluate patients with WAD at risk of chronification to enhance rehabilitation and promote an early return to work. In patients with low back pain (LBP), functional capacity evaluation (FCE) contributes to clinical decisions regarding fitness-for-work. FCE should have demonstrated sufficient clinimetric properties. Reliability and safety of FCE for patients with WAD is unknown.

METHODS

Thirty-two participants (11 females and 21 males; mean age 39.6 years) with WAD (Grade I or II) were included. The FCE consisted of 12 tests, including material handling, hand grip strength, repetitive arm movements, static arm activities, walking speed, and a 3 min step test. Overall the FCE duration was 60 min. The test-retest interval was 7 days. Interclass correlations (model 1) (ICCs) and limits of agreement (LoA) were calculated. Safety was assessed by a Pain Response Questionnaire, observation criteria and heart rate monitoring.

RESULTS

ICCs ranged between 0.57 (3 min step test) and 0.96 (short two-handed carry). LoA relative to mean performance ranged between 15 % (50 m walking test) and 57 % (lifting waist to overhead). Pain reactions after WAD FCE decreased within days. Observations and heart rate measurements fell within the safety criteria.

CONCLUSIONS

The reliability of the WAD FCE was moderate in two tests, good in five tests and excellent in five tests. Safety-criteria were fulfilled. Interpretation at the patient level should be performed with care because LoA were substantial.

Psychological factors unrelated to activity level in patients with chronic musculoskeletal pain

BACKGROUND

Enhancement of physical activities is an important goal in rehabilitation programmes for patients with chronic musculoskeletal pain (CMP). A relationship between activity level and psychological factors is suggested but studied scarcely.

AIM

To explore the relationship between the activity level and psychological factors in patients with CMP.

METHODS

Study design is cross-sectional, explorative. Participants are patients with CMP, included for outpatient multidisciplinary pain rehabilitation.

MEASURES

Activity level was measured by the RT3 accelerometer during 1 week; pain intensity was measured with a 100-mm visual analogue scale; depression, somatization and distress were measured with Symptom Checklist-90-Revised (SCL-90-R), coping strategy with the Utrecht Coping List (UCL, scales active coping, passive coping, avoiding), fear of movement measured with Tampa Scale of Kinesiophobia (TSK), scale activity avoidance. Depending on data distribution, correlations between the mean number of activity counts and psychological factors were tested with Pearson or Spearman correlation coefficients.

RESULTS

Fifty three patients were included: age mean 39.9 years [standard deviation (SD) 11.3]; activity counts per day mean 198,243 (SD 78,000); pain intensity mean 58 (SD 27.7); SCL-90-R mean 149.4 (SD 42.5); UCL active coping mean 17.9 (SD 3.7); UCL passive coping mean 12.3 (SD 3.7); UCL avoiding mean 15.3 (SD 3.0); TSK total mean 35.4 (SD 7.4); TSK activity avoidance mean 16.9 SD (4.7). Correlations between psychological factors and the mean number of activity counts per day ranged from r = -0.27 to r = 0.01 and were all non-significant (p ≥ 0.05).

CONCLUSION

Psychological factors and activity level were unrelated in patients with CMP.

Are performance-based measures predictive of work participation in patients with musculoskeletal disorders? A systematic review

Objective

Assessments of whether patients with musculoskeletal disorders (MSDs) can participate in work mainly consist of case history, physical examinations, and self-reports. Performance-based measures might add value in these assessments. This study answers the question: how well do performance-based measures predict work participation in patients with MSDs?

Methods

A systematic literature search was performed to obtain longitudinal studies that used reliable performance-based measures to predict work participation in patients with MSDs. The following five sources of information were used to retrieve relevant studies: PubMed, Embase, AMA Guide to the Evaluation of Functional Ability, references of the included papers, and the expertise and personal file of the authors. A quality assessment specific for prognostic studies and an evidence synthesis were performed.

Results

Of the 1,230 retrieved studies, eighteen fulfilled the inclusion criteria. The studies included 4,113 patients, and the median follow-up period was 12 months. Twelve studies took possible confounders into account. Five studies were of good quality and thirteen of moderate quality. Two good-quality and all thirteen moderate-quality studies (83%) reported that performance-based measures were predictive of work participation. Two good-quality studies (11%) reported both an association and no association between performance-based measures and work participation. One good-quality study (6%) found no effect. A performance-based lifting test was used in fourteen studies and appeared to be predictive of work participation in thirteen studies.

Conclusions

Strong evidence exists that a number of performance-based measures are predictive of work participation in patients with MSDs, especially lifting tests. Overall, the explained variance was modest.

Work participation and health status in early osteoarthritis of the hip and/or knee: a comparison between the Cohort Hip and Cohort Knee and the Osteoarthritis Initiative

OBJECTIVE

To examine the work participation of Dutch people with early osteoarthritis (OA) in hips or knees and compare this with data from the American Osteoarthritis Initiative (OAI) cohort. The influence of health status and personal factors on work participation was analyzed.

METHODS

In the Cohort Hip and Cohort Knee (CHECK) study, 1,002 subjects were included. Baseline questionnaire data from 970 subjects were analyzed. Rate ratios were calculated to compare work participation with the general Dutch population, after correcting (by stratifying) for age, sex, and education. Health status was measured using the Short Form 36 health survey and the Western Ontario and McMaster Universities Osteoarthritis Index. Groups were compared (CHECK versus OAI, workers versus nonworkers) using t-tests.

RESULTS

The mean age of the subjects was 56 years and 79% were women. Overall participation was 51%, similar to the general Dutch population and lower than in the OAI (76%). Point prevalence of sick leave because of hip/knee symptoms was 2%, and year prevalence was 12%. Of the subjects, 14% had made work adaptations. Workers reported significantly better health status (corrected for age, sex, and education) than nonworkers.

CONCLUSION

Work participation of Dutch people with early OA is similar to the general population and significantly lower than American subjects. Increasing age, female sex, and lower education level were related to lower participation. Societal factors appear to have had more effect on work participation than health status in this stage of OA. The better health status of workers could not be explained solely by selection bias, but may be a result of work.

Self-reported functional status as predictor of observed functional capacity in subjects with early osteoarthritis of the hip and knee: a diagnostic study in the CHECK cohort

OBJECTIVES

Patients with hip or knee osteoarthritis (OA) may experience functional limitations in work settings. In the Cohort Hip and Cohort Knee study (CHECK) physical function was both self-reported and measured performance-based, using Functional Capacity Evaluation (FCE). Relations between self-reported scores on SF-36 and WOMAC (Western Ontario and McMaster Arthritis Index, function scales) and FCE performance were studied, and their diagnostic value for clinicians in predicting observed physical work limitations was assessed.

METHODS

Ninety-two subjects scored physical function on SF-36 (scale 0-100, 100 indicating the best health level) and WOMAC (scale 0-68, 68 indicates maximum restriction) and performed the FCE. Correlations were calculated between all scores. Cross-tables were constructed using both questionnaires as diagnostic tests to identify work limitations. Subjects lifting <22.5 kg on the FCE-test 'lifting-low' were labeled as having physical work limitations. Diagnostic aspects at different cut-off scores for both questionnaires were analysed.

RESULTS

Statistically significant correlations (Spearman's rho 0.34-0.49) were found between questionnaire scores and lifting and carrying tests. Results of a diagnostic cross-table with cut-off point <60 on SF-36 'physical functioning' were: sensitivity 0.34, specificity 0.97 and positive predictive value (PV+) 0.95. Cut-off point > or =21 on WOMAC 'function' resulted in sensitivity 0.51, specificity 0.88 and PV+ 0.88.

CONCLUSION

Low self-reported function scores on SF-36 and WOMAC diagnosed subjects with limitations on the FCE. However, high scores did not guarantee performance without physical work limitations. These results are specific to the tested persons with early OA, in populations with a different prevalence of limitations, different diagnostic values will be found. FCE may be indicated to help clinicians to assess actual work capacity.

Functional capacity evaluation in subjects with early osteoarthritis of hip and/or knee; is two-day testing needed?

INTRODUCTION

The Work Well Functional Capacity Evaluation (WW FCE) is a two-day performance based test consisting of several work-related activities. Three lifting and carrying test items may be performed on both days. The objective of this study was to assess the need for repeated testing of these items in subjects with early osteoarthritis of the hip and/or the knee and to analyze sources of variation between the 2 days of measurement.

METHODS

A standardized WW FCE protocol was applied, including repeated testing of lifting low, lifting overhead and carrying. Differences and associations between the 2 days were calculated using paired samples t-tests, intraclass correlation coefficients (ICC) and limits of agreement (LoA). Possible sources of individual variation between the 2 days were identified by Wilcoxon signed ranks tests. Pearson correlation coefficients were calculated for differences in performances between days and differences in possible sources of variation between days.

RESULTS

Seventy-nine subjects participated in this study, their mean (SD) age was 56.6 (4.8) years, median (min-max) WOMAC (Western Ontario and McMaster Universities) index scores for pain, stiffness and physical function were 5 (0-17), 3 (0-7) and 14 (0-49), respectively. Median (min-max) SF36 physical function was 75 (5-95), and SF36 pain score was 67 (12-76). Mean performance differences ranged from -0.2 to -0.8 kg (P > 0.05). ICC's ranged from 0.75 (lifting overhead) to 0.88 (lifting low). LoA were: lifting low 8.0 kg; lifting overhead 6.5 kg; carrying 9.0 kg. Pearson's correlations were low and non-significant.

CONCLUSIONS

All three tests show acceptable two-day consistency. WW FCE testing on two consecutive days is not necessary for groups of subjects with early osteoarthritis. Individual sources of variation could not be identified.

Preliminary evaluation of a multidisciplinary pain management program for children and adolescents with chronic musculoskeletal pain

PURPOSE

To describe the outcome of a multidisciplinary pain management program for children and adolescents with chronic musculoskeletal pain.

METHODS

STUDY DESIGN

exploratory retrospective cohort study. The study sample consisted of a cohort of 70 children and adolescents (age: 8-21 years) with chronic musculoskeletal pain who completed a 3-month inpatient multidisciplinary pain management program. The program consisted of graded physical exercises, graded activities and counseling of the children and their parents. Assessed were motor and social activities, pain intensity, global assessment of physical functioning and psychosocial well-being (by patient and physician), understanding of the pain process and reduction of medical consumption. Assessments were performed at pre-admission, day of admission, day of discharge and at three months after discharge. Data collection took place over a 10-year period.

RESULTS

Compared to admission, at discharge there were significant improvements in motor performances, school attendance, reduction of pain scores, understanding of the chronic pain process and reduction of medical consumption. Results remained stable at follow-up after three months.

CONCLUSION

The results of this study indicate that a multidisciplinary pain management program for children and adolescents with chronic musculoskeletal pain may be effective.

Material handling performance of patients with chronic low back pain during Functional Capacity Evaluation: A comparison between three countries

PURPOSE

Functional Capacity Evaluations (FCEs) are batteries of tests designed to measure patients' ability to perform work-related activities. Although FCEs are used worldwide, it is unknown how patients' performances compare between countries or settings. This study was performed to explore similarities and differences in FCE performance of patients with chronic low back pain (CLBP) between three international settings that utilize the same FCE protocol.

METHODS

Standardized FCEs were performed on three cohorts of patients with CLBP: A sample from an outpatient rehabilitation context in The Netherlands (n = 121), a Canadian sample in a Worker's Compensation context (n = 273), and a Swiss sample in an inpatient rehabilitation context (n = 170). Patients were undergoing FCE as part of their usual clinical care. Means and standard deviations of maximum performance on the FCE material handling items were calculated and differences compared using ANOVA. Multivariable linear regression was used to determine the relationship between country of origin and FCE performance while controlling for potential confounders including, age, sex, duration of back pain problems, and self-reported pain and disability ratings.

RESULTS

Compared to the Dutch sample, the mean performance of patients in the Canadian and Swiss samples was consistently lower on all FCE items. This association remained statistically significant after controlling for potential confounders.

CONCLUSIONS

Considerable differences were observed between settings in maximum weight handled on the various FCE items. Future FCE research should examine the effects of a number of potentially influential factors, including variability in evaluator judgements across settings, the evaluator-patient interaction and patients' expectations of the influence of FCE results on disability compensation.

Back pain and backpacks in children: Biomedical or biopsychosocial model?

Public press, professional organisations and journals have been sending alarming messages about the rising prevalence of back pain in school age children. Carrying backpacks has been suggested as one of the key factors contributing to back pain in children. The basic assumption based on the biomedical model is that the maturing spine cannot handle the mechanical load of the backpack sufficiently. A review of the evidence in the professional literature, however, revealed very limited evidence to support this assumption. On the contrary, the literature does suggest that psychological and social factors may be of greater importance to explain back pain in children. We conclude this clinical commentary postulating that the public, children and their parents are better served with a more modest and balanced perspective of the professionals, and propose that back pain in children (as it is in adults) should be viewed from a biopsychosocial model.

Relationship between psychological factors and performance-based and self-reported disability in chronic low back pain

Cross sectional study, performed in an outpatient university based pain rehabilitation setting. To analyze the relationship between psychological factors (psychosocial distress, depression, self efficacy, self-esteem, fear of movement, pain cognitions and coping reactions) and performance-based and self-reported disability, as measured with a Functional Capacity Evaluation (FCE) and the Roland Morris Disability Questionnaire (RMDQ), in patients with chronic low back pain (CLBP). It has been suggested that a strong relationship exists between psychological factors and disability in patients with CLBP. In former research disability was often measured by self-report and seldom performance-based. Study sample consisted of 92 patients with CLBP admitted for multidisciplinary rehabilitation. Prior to treatment, all patients completed questionnaires to measure psychological factors and self-reported disability, and performed an FCE to measure performance-based disability. Correlation coefficients between psychological variables and FCE and self-reported disability were calculated. Multivariate linear regression analyses were performed with self-reported or performance based disability measures as outcome variables, and psychological measures as predictor variables. Out of 42 relations analyzed, 5 were statistically significant. This concerned one significant correlation between kinesiophobia and a subtest of FCE, and four correlations between psychological factors and RMDQ. No correlation was significant after the Bonferroni correction was applied (P < 0.001). The strength of significant correlations ranged from r = −0.33 to r = 0.25. The multivariate analysis revealed that psychological variables measured in this study could explain 19% of the variance of self-reported disability, with kinesiophobia being the only psychological variable that contributed significantly. The suggested strong relationship between psychological factors and performance-based and self-reported disability could not be confirmed in this study. This may implicate that the relationship between psychological factors and disability in patients with CLBP is not as unambiguous as suggested.

Matching FCE activities and work demands: an explorative study

OBJECTIVES

to explore to what extent the standardized Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) can be matched with observed work demands in workers with chronic low back pain, and, secondly, to explore whether this match can predict sick leave in the year after rehabilitation treatment.

METHODS

An explorative prognostic cohort study with a one-year follow-up (four, eight and twelve months after baseline) was performed (n = 18). Demographics, back complaints and FCE performance were assessed at baseline. In addition, a workplace assessment (WPA) was performed. Eleven FCE activities were matched with work demands. Sick leave associated with low back pain and physical and psychosocial work demands were assessed during follow-up.

RESULTS

Seven activities could be directly matched with WPA data. (Carrying, pushing, pulling, crouching, kneeling, static forward bending, and dynamic bending and rotating.) For some workers, difficulties existed in matching three of the activities (pushing, pulling and crouching). One activity (lifting) could indirectly be matched with WPA data. One activity (walking) could not be matched with WPA data. Two activities (sitting, standing) were excluded from analyses due to practical limitations. No relation was found between FCE performance, work demands, and sick leave during follow-up.

CONCLUSIONS

Seven FCE activities could be directly matched with work demands. However, not all observed work demands could be matched with IWS FCE activities in the eighteen occupations studied. This quantitative and standardized way of assessing work-related disability is not sufficient to predict work ability and sick leave at the present time.

Test-retest reliability of a WRULD functional capacity evaluation in healthy adults

The aim of this study was to determine test-retest reliability of a Functional Capacity Evaluation for patients with non-specific Work Related Upper Limb Disorders (WRULD FCE). The study sample included 33 healthy adults, consisting of 14 males and 19 females with a mean age of 29.2 years. The WRULD FCE consisted of 8 different tests including 26 items measuring repetitive movements, duration, working in awkward positions, forceful movements and static postures. Two FCE sessions were held with a 10-day interval. Means, 95% confidence intervals, one-way random Intraclass Correlation Coefficients (ICCs), 95% limits of agreement and repeated measures were calculated. An ICC between 0.75 and 0.90 was considered as good and an ICC above 0.90 was considered as an excellent reliability. The results showed that 14 of 26 items (54%) had excellent reliability, 9 of 26 items (35%) had good reliability and 3 of 26 items (11%) had moderate reliability based on ICC values. Significant learning effects were present in the Purdue Pegboard Task and in the Complete Minnesota Dexterity Test. It is concluded that the WRULD FCE is reliable in healthy adults.

Basis for an FCE methodology for patients with work-related upper limb disorders

A reported reduction in work-related functional capacity in Work-related Upper Limb Disorders (WRULD) patients is among the most common problems in WRULD. The extent to which this reduction in functional capacity can be objectified remains unknown. A validated instrument to test functional capacity in this patient group is unavailable. The objective of this study was to design a Functional Capacity Evaluation (FCE) for WRULD patients working with Visual Display Units (VDU) and provide evidence for content validity. A review to epidemiological literature was conducted to identify physical risk factors for VDU-related WRULD. The results indicate that physical risk factors were related to repetition, duration, working in awkward and static positions and forceful movements of the upper extremity and neck. An FCE was designed based on the risk factors identified. Eight tests were selected to cover all risk factors: the overhead lift, overhead work, repetitive reaching, handgrip strength, finger strength, wrist extension strength, fingertip dexterity, and a hand and forearm dexterity test. Content validity of this FCE was established by providing the rationale, specific objectives and operational definitions of the FCE. Further research is needed to establish reliability and other aspects of validity of the WRULD FCE.

Test-retest reliability of the Isernhagen Work Systems Functional Capacity Evaluation in healthy adults

Aim of this study was to investigate test-retest reliability of the Isernhagen Work System Functional Capacity Evaluation (IWS FCE) in healthy subjects. The IWS FCE consists of 28 tests that reflect work-related activities such as lifting, carrying, bending, etc. A convenience sample of 26 healthy subjects participated in the study. The subjects' mean age was 34.9 years. Two FCE sessions were held within a 2-3 week interval. Descriptives per session, Intra Class Correlations (ICC), limits of agreement, Cohen's Kappa, and percentage of agreement were calculated where appropriate. An ICC of > or =0.75, a Kappa value > or =0.60, and a percentage of absolute agreement of > or =80% were considered acceptable reliability. Acceptable reliability was demonstrated for seven out of nine tests (78%) of the material handling group and the shuttle walk test based on ICC analyses only. Sixteen out of 17 criterion and ceiling tests (94%) showed acceptable reliability based on Kappa values and percentage of agreement. Of these 17 tests, 8 were eligible for further analysis, and of those 8 tests the reliability of one test was acceptable based on ICC analyses (13%). In conclusion, the test-retest reliability of the material-handling group is acceptable. Crude analyses of the ceiling and criterion tests reveal acceptable test-retest reliability of most, but not all, tests.

Measuring physical performance via self-report in healthy young adults

Discrepancies exist in literature as to what extent self-reporting can replace performance-based testing. To answer this question, self-reports and performance tests should measure identical constructs. Previous studies did not measure identical constructs. The objective of our study was to investigate to what extent self-reporting can replace performance-based testing. Seventy-two healthy subjects were tested. The constructs of the self-reports and the performance tests covered the same components to enable a comparison of self-reports and performance test results. Three different self-reports and a performance test were used to measure physical performance. Additionally, rating of perceived exertion was measured after the subjects lifted a reference weight to predict maximal lifting performance. The controls were age, gender, educational level, subject's participation in fitness, availability of reference data, motivation, attitude, general self-efficacy, and mood. Results showed that all lifting tasks could be predicted, though not solely via self-reporting. A prediction of the performance test results with a margin of +/-5 kg of error could be made for at least 79% of the subjects, via gender, self-reporting, and subject's participation in fitness. Self-reporting may not replace performance testing, although performance testing can be predicted with a margin of error of +/- 5 kg for at least 79% of the healthy subjects.