Testing lifting capacity: validity of determining effort level by means of observation

Tele-Assessment of Functional Capacity: Validity, Intra- and Inter-rater Reliability

BACKGROUND

Functional capacity evaluation is a standardized tool that assesses work-related skills. Although there are different test batteries, the most frequently used one is Work Well Systems. This study aims to determine the validity and inter- and intra-rater reliability of remote implementation of functional capacity tests (repetitive reaching, lifting object overhead, and working overhead) in asymptomatic individuals.

METHODS

A total of 51 asymptomatic individuals were included in the study. Participants completed all tests both face-to-face and remotely. Remote assessment videos were rewatched by the same researcher and different researchers for intra- and inter-rater reliability. All processes were scored by two independent researchers.

RESULTS

Remotely performing repetitive reaching (intraclass correlation coefficient [ICC]: 0.85-0.92, p < .001), lifting object overhead (ICC: 0.98, p < .001), and working overhead (ICC: 0.88 p < .001) tests are valid and reliable.

DISCUSSION

Repetitive reaching, lifting an object overhead, and sustained overhead work tests in the Work Well Systems-Functional Capacity Evaluation test battery can be performed remotely through videoconferencing. Remotely evaluating these tests, which are especially important in work-related situations, may be important in pandemic conditions and hybrid working conitions.

Central sensitization and functioning in patients with chronic low back pain: A cross-sectional and longitudinal study

BACKGROUND

Central sensitization (CS) is present in a subgroup of patients with chronic low back pain (CLBP). Studies on the relationship between CS and functioning have limited operationalizations of CS and functioning.

OBJECTIVE

To determine whether CS was related to functioning in patients with CLBP (cross-sectional); and to determine whether changes in CS were related to changes in functioning (longitudinal).

METHODS

An observational prospective cohort study with data collected at baseline and discharge of an interdisciplinary pain rehabilitation program was executed. CS indicators: CS Inventory part A (CSI-A), quantitative sensory testing (QST), root mean square of successive differences of heart-rate variability (RMSSD). Functioning measures: lifting capacity, physical functioning subscale of Rand36 (Rand36-PF), Work Ability Score (WAS), Pain Disability Index (PDI). Main analyses included correlation and multiple regression controlling for confounders; cross-sectional with baseline data and longitudinal with deltas (Δ).

RESULTS

76 patients with primary CLBP participated at baseline and 56 at discharge. Most associations were weak (cross-sectional r𝑝𝑎𝑟𝑡𝑖𝑎𝑙=-0.30-0.24; longitudinal r𝑝𝑎𝑟𝑡𝑖𝑎𝑙=-0.37-0.44). Cross-sectional multiple regression significant associations: mechanical pain threshold-QST and lifting capacity (r𝑝𝑎𝑟𝑡𝑖𝑎𝑙=-0.39), parasympathetic/vagal tone-RMSSD and physical functioning-Rand36-PF (r𝑝𝑎𝑟𝑡𝑖𝑎𝑙= 0.26). Longitudinal multiple regression significant associations: Δ parasympathetic/vagal tone-RMSSD and Δ lifting capacity (r𝑝𝑎𝑟𝑡𝑖𝑎𝑙= 0.48), ΔCSI-A and Δdisability-PDI (r𝑝𝑎𝑟𝑡𝑖𝑎𝑙= 0.36). Cross-sectional and longitudinal final regression models explained 24.0%-58.3% and 13.3%-38.0% of total variance.

CONCLUSION

CS was weakly related to functioning, and decreases in CS were weakly-moderately related to increases in functioning.

Towards the Use of 2D Video-Based Markerless Motion Capture to Measure and Parameterize Movement During Functional Capacity Evaluation

Purpose The objective of this study was to determine the agreement of kinematic parameters calculated from motion data collected via a 2D video-based pose-estimation (markerless motion capture) approach and a laboratory-based 3D motion capture approach during a floor-to-waist height functional lifting test. Method Twenty healthy participants each performed three floor-to-waist height lifts. Participants' lifts were captured simultaneously using 2D video (camcorder) in the sagittal plane and 3D motion capture (Vicon, Oxford, UK). The three lifts were representative of a perceived light, medium, and heavy load. Post-collection, video data were processed through a pose-estimation software (i.e., markerless motion capture). Motion data from 3D motion capture and video-based markerless motion capture were each used to calculate objective measures of interest relevant to a functional capacity evaluation (i.e., posture, balance, distance of the load from the body, and coordination). Bland-Altman analyses were used to calculate agreement between the two methods. Results Bland-Altman analysis revealed that mean differences ranged from 1.9° to 22.1° for posture and coordination-based metrics calculated using markerless and 3D motion capture, respectively. Limits of agreement for most posture and coordination measures were approximately + 20°. Conclusions 2D video-based pose estimation offers a strategy to objectively measure movement and subsequently calculated metrics of interest within an FCE context and setting, but at present the agreement between metrics calculated using 2D video-based methods and 3D motion capture is insufficient. Therefore, continued effort is required to improve the accuracy of 2D-video based pose estimation prior to inclusion into functional testing paradigms.

Changes in kinematics and work physiology during progressive lifting in healthy adults

PURPOSE

To analyze progression of changes in kinematics and work physiology during progressive lifting in healthy adults.

METHODS

Healthy participants were recruited. A standardized lifting test from the WorkWell Functional Capacity Evaluation (FCE) was administered, with five progressive lifting low series of five repetitions. The criteria of the WorkWell observation protocol were studied: changes in muscle use (EMG), heart rate (heart rate monitor), base of support, posture and movement pattern (motion capture system). Repeated measures ANOVA's were used to analyze changes during progressive workloads.

RESULTS

18 healthy young adults participated (8 men, 10 women; mean age 22 years). Mean maximum weight lifted was 66 (±3.2) and 44 (±7.4) kg for men and women, respectively. With progressive loads, statistically significant (p < 0.01) differences were observed: increase in secondary muscle use at moderate lifting, increase of heart rate, increase of base of support and movement pattern changes were observed; differences in posture were not significant.

CONCLUSIONS

Changes in 4 out of 5 kinematic and work physiology parameters were objectively quantified using lab technology during progressive lifting in healthy adults. These changes appear in line with existing observation criteria.

Task-Contingent Persistence is Related to Better Performance-Based Measures in Patients with Chronic Musculoskeletal Pain

Purpose

Pacing, avoidance, and overdoing are considered the three main behavioral strategies, also labeled activity patterns. Their relationship with functioning of patients with chronic pain is debated. The purpose of this study was to measure the influence of activity patterns on lifting tasks commonly used in daily life.

Method

We performed a monocentric observational study and included patients performing Functional Capacity Evaluation (FCE). Avoidance, pacing, and persistence were assessed with using the Patterns of Activity Measures-Pain (POAM-P). Maximal safe performance was measured for floor-to-waist, waist-to-overhead, horizontal lift, and carrying with dominant-hand tests according to the FCE guidelines. Descriptive statistics, associations of POAM-P subscales with various sociodemographic variables, and correlations are presented. Standard multiple linear regression models were applied to measure the associations between FCE tests and POAM-P subscales, adjusting for the following potential confounders: age, gender, body mass index (BMI), pain severity, trauma severity, localization of injury, and education.

Results

Persistence was significantly positively associated with performance on the 4 FCE tests: floor-to-waist (coefficient = 0.20; p=0.001), waist-to-overhead (coefficient = 0.13; p=0.004), horizontal lift (coefficient = 0.31; p ≤ 0.001), and dominant-handed lifting (coefficient = 0.19; p=0.001). Pacing was found to have a negative influence on the carrying dominant-hand test (coefficient = -0.14; p=0.034), and avoidance was not found to have an influence on the 4 FCE tests.

Conclusion

This study shows that task-persistence pattern is positively associated with physical performance in FCE, whereas pacing can have a negative influence on some tests.

Do wearable fitness devices correlate with performance-based tests of work-related functional capacity?

BACKGROUND

The use of wearable accelerometers in conjunction with Functional Capacity Evaluation (FCE) may provide additional useful information about maximum performance in workers and enhance the validity of functional testing. However, little research has been conducted to compare accelerometer output with performance during FCE.

OBJECTIVE

The objectives of this study were to: (1) Determine the magnitude and direction of correlation between participant performance on five FCE tasks and scores from Actigraph activity monitors; and (2) Compare the results of two different placements of Actigraph devices.

METHOD

We used a cross-sectional design and convenience sampling to collect data from 46 healthy participants. Each participant completed 5 functional tasks selected from the WorkWell FCE protocol while wearing 2 Actigraph devices, 1 on the dominant side waist and 1 on the non-dominant wrist. The FCE tasks included 5-repetition maximum lifting (floor-to-waist, waist to crown and front carry), a sustained overhead work endurance task, and the 6-minute walk test. Analysis included calculating Pearson regression coefficients between maximum FCE item performance and Actigraph vector magnitudes (VM) along with Intraclass Correlation Coefficients (ICC) to compare VM activity counts derived from the Actigraphs on the waist and wrist.

RESULTS

Thirty-Nine (84.8%) participants had complete data and were included in analysis. Findings indicate Actigraph VM data from the device worn on the waist correlated positively with maximum lift performance (r = 0.39-0.64, p < 0.001 to 0.08) and 6-minute walk distance (r = 0.66, p < 0.001). Actigraph data from wrist placement were not significantly correlated with FCE performance on any of the functional tasks, except when comparing average VM data and waist to crown lift (r = 0.44, p < 0.001). There was no significant correlation in either Actigraph placement for VM and overhead work time. ICCs between the two Actigraph placements ranged from poor to acceptable agreement (ICC = 0.24-0.70, p < 0.001 to 0.19).

CONCLUSIONS

Actigraph device output correlated moderately with maximum performance on FCE lift and ambulation tests. Waist placement appears more suitable than wrist during performance-based tests.

Lifting capacity is associated with central sensitization and non-organic signs in patients with chronic back pain

Purpose: To analyze the associations between lifting capacity, and central sensitization (CS) and non-organic signs (NOS) in patients with chronic back pain (CBP) attending vocational rehabilitation.Materials and methods: Cross-sectional observational multicenter study among patients with CBP undergoing a return to work assessment within care as usual. Main analyses: step 1: partial correlation between lifting capacity, and CS, NOS, and additional variables; step 2: multiple regression in stepwise forward method for dependent variable lifting capacity, and for independent variables CS and NOS, and additional variables significant (p < 0.05) at step 1. All analyses were controlled for sex.Results: Fifty-six patients of mean age 42.5 years and 59% women participated in the study. Correlations between lifting capacity and CS and NOS were r = -0.53 and r = -0.50, respectively. CS and NOS, as well as age and sex, contributed significantly to the final regression model, which explained 57.6% of variance.Conclusions: After controlling for confounders, CS and NOS were negatively associated with lifting capacity in patients with CBP. Explained variance was substantially higher than previously reported studies.Implications for RehabilitationThe identification of central sensitization and non-organic signs (NOS) in patients with chronic back pain can alert clinicians about central nervous system being in a hypersensitive state and about pain behavior.Central sensitization and NOS are relevant determinants of lifting capacity.Better understanding of the factors affecting lifting capacity lead to better design and tailoring of interventions, resulting in optimized vocational rehabilitation programs and faster return to work.

Central Sensitisation and functioning in patients with chronic low back pain: protocol for a cross-sectional and cohort study

INTRODUCTION

A relevant subsample of patients with chronic low back pain (CLBP) have manifested augmented central pain processing, central sensitisation (CS). Patients with CLBP have limited functioning and participation. Theoretically, physical functioning in patients with CLBP can plausibly be linked to CS; however, evidence to explain such association is scarce. Moreover, there is no gold standard for CS diagnosis. The objectives of the study are: (1) to analyse the association between instruments assessing reference symptoms and signs attributed to CS; (2) to analyse whether reference symptoms and signs attributed to CS are associated with functioning measurement outcomes; and (3) to analyse whether changes (between baseline and discharge) in reference symptoms and signs attributed to CS are related to changes in each of the functioning measurement outcomes.

METHODS AND ANALYSIS

A cross-sectional and longitudinal observational study is performed with measurements taken at baseline and discharge of an interdisciplinary rehabilitation programme. A sample size of 110 adult patients with CLBP has been calculated for the study. CS measurements are: Central Sensitisation Inventory, quantitative sensory testing and heart rate variability. Functioning measurements are: lifting capacity, maximal aerobic capacity, accelerometry and reported functioning. Statistical analyses to be performed are: (1) correlation between CS measurements, (2) multiple regression between functioning (dependent variable) and CS measurements (independent variable), and (3) multiple regression between changes in scores of functioning (dependent variable) and CS measurements (independent variable), and corrected for sex and age.

ETHICS AND DISSEMINATION

The study obtained the clearance to its implementation from the Medical Research Ethics Committee of the University Medical Center Groningen in July 2017. The results will be disseminated through scientific publications in peer-reviewed journals, presentations at relevant conferences, and reports to stakeholders.

TRIAL REGISTRATION NUMBER

NTR7167/NL6980.

Functional Capacity Evaluation in Different Societal Contexts: Results of a Multicountry Study

Purpose To examine factors associated with Functional Capacity Evaluation (FCE) results in patients with painful musculoskeletal conditions, with focus on social factors across multiple countries. Methods International cross-sectional study was performed within care as usual. Simple and multiple multilevel linear regression analyses which considered measurement's dependency within clinicians and country were conducted: FCE characteristics and biopsychosocial variables from patients and clinicians as independent variables; and FCE results (floor-to-waist lift, six-minute walk, and handgrip strength) as dependent variables. Results Data were collected for 372 patients, 54 clinicians, 18 facilities and 8 countries. Patients' height and reported pain intensity were consistently associated with every FCE result. Patients' sex, height, reported pain intensity, effort during FCE, social isolation, and disability, clinician's observed physical effort, and whether FCE test was prematurely ended were associated with lift. Patient's height, Body Mass Index, post-test heart-rate, reported pain intensity and effort during FCE, days off work, and whether FCE test was prematurely ended were associated with walk. Patient's age, sex, height, affected body area, reported pain intensity and catastrophizing, and physical work demands were associated with handgrip. Final regression models explained 38‒65% of total variance. Clinician and country random effects composed 1-39% of total residual variance in these models. Conclusion Biopsychosocial factors were associated with every FCE result across multiple countries; specifically, patients' height, reported pain intensity, clinician, and measurement country. Social factors, which had been under-researched, were consistently associated with FCE performances. Patients' FCE results should be considered from a biopsychosocial perspective, including different social contexts.

Updating the Evidence on Functional Capacity Evaluation Methods: A Systematic Review

Objectives To synthesize the evidence on the psychometrics functional capacity evaluation (FCE) methods. Methods A systematic literature search in nine databases. The resulting articles were screened based on predefined in- and exclusion criteria. Two reviewers independently performed this screening. Included studies were appraised based on their methodological quality. Results The search resulted in 20 eligible studies about nine different FCE methods. The Baltimore Therapeutic Equipment work simulator showed a moderate predictive validity. The Ergo-Kit (EK) showed moderate variability and high inter- and intra-rater reliability. Low discriminative abilities and high convergent validity were found for the EK. Concurrent validity of the EK and the ERGOS Work Simulator was low to moderate. Moderate to high test-retest, inter- and intra-reliability was found in the Isernhagen Work-Systems (IWS) FCE. The predictive validity of the IWS was low. The physical work performance evaluation (PWPE) showed moderate test-retest reliability and moderate to high inter-rater reliability. Low internal and external responsiveness were found for the PWPE, predictive validity was high. The predictive validity of the short-form FCE was also high but need to be further examined on several psychometric properties. Low discriminative and convergent validity were found for the work disability functional assessment battery. The WorkHab showed moderate to high test-retest, inter- and intra-rater reliability. Conclusion Well-known FCE methods have been rigorously studied, but some of the research indicates weaknesses in their reliability and validity. Future research should address how these weaknesses can be overcome.

Predictive Value of the Fear-Avoidance Model on Functional Capacity Evaluation

Purpose Measuring the predictive value of the Fear-Avoidance Model (FAM) on lifting tasks in Functional Capacity Evaluation (FCE), and on reasons for stopping the evaluation (safe maximal effort, versus self-limited). Methods A monocentric prospective study was conducted on 298 consecutive inpatients. Components of the FAM were analyzed using the Cumulative Psychosocial Factor Index (CPFI: kinesiophobia, catastrophizing, depressive mood) and perceived disability (Hand/Spinal Function Sort: HFS/SFS). Floor-to-waist, waist-to-overhead and dominant-hand lifting tests were measured according to the FCE guidelines. Maximal safe performance was judged by certified FCE assessors. Analyses were conducted with linear multiple regression models. Results The CPFI was significantly associated with the 3 FCE lifting tests: floor-to-waist (ß = - 1.12; p = 0.039), waist-to-overhead (ß = - 0.88; p = 0.011), and dominant-handed lifting (ß = - 1.21; p = 0.027). Higher perceived disability was also related to lower performances: floor-to-waist (ß = 0.09; p < 0.001), waist-to-overhead (ß = 0.04; p < 0.001), and dominant-handed lifting (ß = 0.06; p < 0.001). The CPFI was not related to performances of patients with self-limited effort despite higher psychological scores, while a relationship was found for patients who achieved a safe maximal performance. Higher perceived disability was related to performances in both situations. Conclusions FAM components should be taken into account when interpreting maximal physical performance in FCE. This study also suggests that factors other than pain-related fears may influence patients with self-limited effort.

Decision-Making Data: Expectations for Reproducibility of Lifting on Separate Days

Purpose:

The purpose of this study was to explore the difference in maximal lifting capability between 2 modes of lifting (traditional crate and XRTS Lever Arm) over multiple days. The differences in absolute strength values were compared with existing criteria for sincere effort during distraction-based lifting. In addition, rate of perceived exertion (RPE) is presented for the 2 modes of lifting on each day.

Primary Practice Setting:

Workers' compensation.

Methodology and Sample:

Forty-four subjects between the ages of 20 and 44 years participated in this study. Investigators established 1 repetition maximum (RM) for each subject performing the crate lift. Subjects were randomly assigned 5 weights ranging from 10% to 100% of their determined 1RM and asked to give their rating of perceived exertion after each lift. The same procedure was repeated 2–5 days later using the XRTS Lever Arm. Paired t tests and Spearman's correlation coefficient were used for data analysis. Alpha was set at less than .05.

Results:

There was a statistically significant difference (p < .04) between maximal lift values for the 2 lifting modes. The percent difference between the modes of lifting was 10.5% ± 6.4%. In addition, there was a positive correlation between the RPE on the 2 modes of lifting (p = .87).

Implications for Case Management Practice:

A functional capacity evaluation (FCE) is typically ordered after the completion of physical rehabilitation and before releasing a patient to full or modified duty. In addition to assessing the ability to function within normal job demands, an assessment of effort by the participant typically takes place during an FCE. Case managers and physicians are presented with information, allowing them to make comparisons between functional lifting abilities displayed during treatment sessions and the FCE. These comparisons may often take place with the subpoena of medical records and may be discussed during the deposition or trial process. If an FCE takes place at a different facility than the physical therapy or work conditioning treatment, 2 different modes of lifting may take place based on the equipment within each facility. The results of this study indicate that the 2 modes of lifting on separate days meet established criteria for lift comparison testing during FCEs.

Reliability of physical functioning tests in patients with low back pain: a systematic review

PURPOSE

The aim of this study was to provide a comprehensive overview of physical functioning tests in patients with low back pain (LBP) and to investigate their reliability.

DATA SOURCES

A systematic computerized search was finalized in four different databases on June 24, 2017: PubMed, Web of Science, Embase, and MEDLINE.

STUDY SELECTION

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed during all stages of this review. Clinical studies that investigate the reliability of physical functioning tests in patients with LBP were eligible. The methodological quality of the included studies was assessed with the use of the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist. To come to final conclusions on the reliability of the identified clinical tests, the current review assessed three factors, namely, outcome assessment, methodological quality, and consistency of description.

DATA SYNTHESIS

A total of 20 studies were found eligible and 38 clinical tests were identified. Good overall test-retest reliability was concluded for the extensor endurance test (intraclass correlation coefficient [ICC]=0.93-0.97), the flexor endurance test (ICC=0.90-0.97), the 5-minute walking test (ICC=0.89-0.99), the 50-ft walking test (ICC=0.76-0.96), the shuttle walk test (ICC=0.92-0.99), the sit-to-stand test (ICC=0.91-0.99), and the loaded forward reach test (ICC=0.74-0.98). For inter-rater reliability, only one test, namely, the Biering-Sörensen test (ICC=0.88-0.99), could be concluded to have an overall good inter-rater reliability. None of the identified clinical tests could be concluded to have a good intrarater reliability.

CONCLUSIONS

Further investigation should focus on a better overall study methodology and the use of identical protocols for the description of clinical tests. The assessment of reliability is only a first step in the recommendation process for the use of clinical tests. In future research, the identified clinical tests in the current review should be further investigated for validity. Only when these clinimetric properties of a clinical test have been thoroughly investigated can a final conclusion regarding the clinical and scientific use of the identified tests be made.

Normative kinematics of reaching and dexterity tasks: moving towards a quantitative baseline for Functional Capacity Evaluations (FCEs)

Purpose: This work generates a comprehensive description of upper extremity and torso kinematics of a healthy population during reaching and dexterity Functional Capacity Evaluation (FCE) tasks. Methods: Upper limb and torso kinematic data were collected from 30 young, healthy participants as they performed three common FCE tasks: repetitive reaching, fingertip dexterity, and hand and forearm dexterity. Kinematic profiles were created for all clinically relevant angles of the torso, shoulder, elbow, and wrist. Results: These provocative tasks require large ranges of motion and create high demand postures for the upper limb, specifically at the shoulder. Arm elevation was up to 90°, while humeral internal rotation of 25° was observed. Torso angles were typically below 30° from neutral and elbow flexion remained within 90°–120° for nearly all tasks. Wrist ulnar deviation ranged from 0° to 26° for both wrists. Conclusion: The normative data created in this investigation provide a description of healthy motion during reaching and dexterity tasks. These normative curves are the initial step towards understanding movement that would contraindicate return to work during an FCE. This work supports a future clinical goal of being able to identify persons at risk of further injury or disability if returned to work too early.

WITHDRAWN: Functional capacity evaluations for the prevention of occupational re-injuries in injured workers

This review did not find any studies to include in 2010. Systematic searches have not revealed any new studies having been published up to November 2015. As the current author team cannot commit to updating the review and as we haven’t found new authors keen to take on the task, we decided to withdraw this review.

The editorial group responsible for this previously published document have withdrawn it from publication.

Influence of Physical Therapists' Kinesiophobic Beliefs on Lifting Capacity in Healthy Adults

BACKGROUND

Physical therapists' recommendations to patients to avoid daily physical activity can be influenced by the therapists' kinesiophobic beliefs. Little is known about the amount of influence of a physical therapist's kinesiophobic beliefs on a patient's actual lifting capacity during a lifting test.

OBJECTIVE

The objective of this study was to determine the influence of physical therapists' kinesiophobic beliefs on lifting capacity in healthy people.

DESIGN

A blinded, cluster-randomized cross-sectional study was performed.

METHODS

The participants (n=256; 105 male, 151 female) were physical therapist students who performed a lifting capacity test. Examiners (n=24) were selected from second-year physical therapist students. Participants in group A (n=124) were tested in the presence of an examiner with high scores on the Tampa Scale of Kinesiophobia for health care providers (TSK-HC), and those in group B (n=132) were tested in the presence of an examiner with low scores on the TSK-HC. Mixed-model analyses were performed on lifting capacity to test for possible (interacting) effects.

RESULTS

Mean lifting capacity was 32.1 kg (SD=13.6) in group A and 39.6 kg (SD=16.4) in group B. Mixed-model analyses revealed that after controlling for sex, body weight, self-efficacy, and the interaction between the examiners' and participants' kinesiophobic beliefs, the influence of examiners' kinesiophobic beliefs significantly reduced lifting capacity by 14.4 kg in participants with kinesiophobic beliefs and 8.0 kg in those without kinesiophobic beliefs.

LIMITATIONS

Generalizability to physical therapists and patients with pain should be studied.

CONCLUSIONS

Physical therapists' kinesiophobic beliefs negatively influence lifting capacity of healthy adults. During everyday clinical practice, physical therapists should be aware of the influence of their kinesiophobic beliefs on patients' functional ability.

Workers' Health Surveillance in the Meat Processing Industry: Work and Health Indicators Associated with Work Ability

BACKGROUND

Workers' health surveillance (WHS) programs commonly measure a large number of indicators addressing health habits and health risks. Recently, work ability and functional capacity have been included as important risk measures in WHS. In order to address work ability appropriately, knowledge of associations with work and health measures is necessary. The objective of this study was to evaluate which of the factors measured in a WHS are independently associated with work ability in a group of meat processing workers.

METHODS

A cross-sectional study was performed in a large meat processing company in The Netherlands. Data were collected during a WHS between February 2012 and March 2014. Personal characteristics, health habits and health-risk indicators, functional capacity, and work-related factors were measured. Work ability was measured with the Work Ability Index and was used as dependent variable. Univariable and multivariable logistic regression analyses were conducted, a receiver operating characteristic curve was constructed and the area under the curve (AUC) was calculated.

RESULTS

Data sets from 230 employees were used for analyses. The average age was 53 years and the average work ability index score was 39.3. In the final multivariable model age (OR 0.94), systolic blood pressure (OR 1.03), need for recovery (OR 0.56), and overhead work capacity (OR 3.95) contributed significantly. The AUC for this model was 0.81 (95% CI 0.75-0.86).

CONCLUSION

Findings from the current study indicate that multifactorial outcomes (age, systolic blood pressure, need for recovery, and overhead work capacity) from a WHS were independently associated with work ability. These factors can be used to assess employees at risk for low work ability and might provide directions for interventions.

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.

The reliability of WorkWell Systems Functional Capacity Evaluation: a systematic review

Background

Functional capacity evaluation (FCE) determines a person’s ability to perform work-related tasks and is a major component of the rehabilitation process. The WorkWell Systems (WWS) FCE (formerly known as Isernhagen Work Systems FCE) is currently the most commonly used FCE tool in German rehabilitation centres. Our systematic review investigated the inter-rater, intra-rater and test-retest reliability of the WWS FCE.

Methods

We performed a systematic literature search of studies on the reliability of the WWS FCE and extracted item-specific measures of inter-rater, intra-rater and test-retest reliability from the identified studies. Intraclass correlation coefficients ≥ 0.75, percentages of agreement ≥ 80%, and kappa coefficients ≥ 0.60 were categorised as acceptable, otherwise they were considered non-acceptable. The extracted values were summarised for the five performance categories of the WWS FCE, and the results were classified as either consistent or inconsistent.

Results

From 11 identified studies, 150 item-specific reliability measures were extracted. 89% of the extracted inter-rater reliability measures, all of the intra-rater reliability measures and 96% of the test-retest reliability measures of the weight handling and strength tests had an acceptable level of reliability, compared to only 67% of the test-retest reliability measures of the posture/mobility tests and 56% of the test-retest reliability measures of the locomotion tests. Both of the extracted test-retest reliability measures of the balance test were acceptable.

Conclusions

Weight handling and strength tests were found to have consistently acceptable reliability. Further research is needed to explore the reliability of the other tests as inconsistent findings or a lack of data prevented definitive conclusions.

Which instruments can detect submaximal physical and functional capacity in patients with chronic nonspecific back pain? A systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To evaluate the validity of instruments that claim to detect submaximal capacity when maximal capacity is requested in patients with chronic nonspecific musculoskeletal pain.

SUMMARY OF BACKGROUND DATA

Several instruments have been developed to measure capacity in patients with chronic pain. The detection of submaximal capacity can have major implications for patients. The validity of these instruments has never been systematically reviewed.

METHODS

A systematic literature search was performed including the following databases: Web of Knowledge (including PubMed and Cinahl), Scopus, and Cochrane. Two reviewers independently selected the articles based on the title and abstract according to the study selection criteria. Studies were included when they contained original data and when they objectified submaximal physical or functional capacity when maximal physical or functional capacity was requested. Two authors independently extracted data and rated the quality of the articles. The included studies were scored according to the subscales "Criterion Validity" and "Hypothesis Testing" of the COSMIN checklist. A Best Evidence Synthesis was performed.

RESULTS

Seven studies were included, 5 of which used a reference standard for submaximal capacity. Three studies were of good methodological quality and validly detected submaximal capacity with specificity rates between 75% and 100%.

CONCLUSION

There is strong evidence that submaximal capacity can be detected in patients with chronic low back pain with a lumbar motion monitor or visual observations accompanying a functional capacity evaluation lifting test.

Physical capability outcomes after total disc replacement with ProDisc-L

Background

Lumbar disc arthroplasty (total disc replacement [TDR]) outcomes have been evaluated using subjective, patient-reported measures of pain, health, and functional impairment. As a condition of TDR coverage, our institution's health plan required that objective physical performance data be collected. Thus our study was designed to explore (1) the feasibility of using preoperative and 1-year postoperative performance on functional capacity tasks as an outcome metric for TDR with ProDisc-L (PD-L) (Synthes Spine, West Chester, Pennsylvania), (2) the magnitude and significance of changes in preoperative and postoperative performance, and (3) whether changes noted in performance are reflected in the subjective measures.

Methods

Seven adapted WorkWell tasks (physical capability assessment tool [PCAT]) (WorkWell Systems, Duluth, Minnesota) were performed preoperatively and 1 year postoperatively by 18 patients who received either single-level or 2-level PD-L implants. Demographic and medical data were reviewed.

Results

The PCAT was implemented easily, and the tasks took approximately 30 minutes to complete. Percent improvement and preoperative and postoperative physical capability outcomes for each PCAT task are as follows: squat, 79% (10.7 ± 7.1 repetitions vs 19.2 ± 2.0 repetitions, P < .001); forward bend, 121% (110.2 ± 68.8 seconds vs 243.6 ± 77.2 seconds, P < .001); kneel, 92% (283.2 ± 173.2 seconds vs 544.7 ± 109.3 seconds, P < .001); floor-to-waist lift, 128% (16.1 ± 9.9 lb vs 36.7 ± 20.3 lb, P < .001); horizontal carry, 119% (19.7 ± 8.6 lb vs 43.2 ± 18.3 lb, P < .001); push, 32% (67.7 ± 19.2 lb vs 89.4 ± 24.4 lb, P < .001); and pull, 40% (57.6 ± 17.1 lb vs 80.9 ± 26.4 lb, P < .001). Visual analog scale scores for pain (5.1 ± 1.7 vs 1.4 ± 1.6, P < .001), Oswestry Disability Index scores (49.0% ± 13.2% vs 15.2% ± 14.3%, P < .001), and amount of narcotic use (26.1 ± 43.8 mg of morphine equivalent vs 1.9 ± 7.3 mg of morphine equivalent, P = .031) also improved. In single-level cases, comparison of L4-5 versus L5-S1 showed significant differences only with the forward bend task (P = .002).

Conclusions/Clinical Relevance

The physical capability outcome may be a feasible outcome metric. PD-L implantation may result in substantial improvements in physical performance. Similar benefits shown in a larger series over a longer timeframe could have important implications for the long-term health, productivity, and cost of health care for this patient population.

Comparison of two methods for interpreting lifting performance during functional capacity evaluation

BACKGROUND

Functional capacity evaluation (FCE) requires determination of effort by observation of effort indexes for performance interpretation. Waddell signs have been shown to be associated with decreased functional performance. Whether determination of effort by observational criteria and Waddell sign testing can be used interchangeably to interpret lifting performance is unknown.

OBJECTIVE

The purposes of this study were to assess the concurrent validity of submaximal effort and Waddell signs and to determine whether these contribute independently to lifting performance.

DESIGN

This investigation was an analytical cross-sectional study.

METHODS

A total of 130 people who had chronic nonspecific low back pain and were referred for fitness-for-work evaluation were included. Physical effort was determined on the basis of observational criteria for lifting from floor to waist, lifting from waist to shoulder, and horizontal lifting during FCE. A second assessor conducted Waddell sign testing. The concurrent validity of Waddell signs and submaximal effort was assessed by calculating sensitivity and specificity. Hierarchical regression analysis was used to determine the contributions of Waddell signs and submaximal effort to lifting performance. Age and sex were covariates.

RESULTS

The FCE assessor found a low sensitivity of Waddell signs for submaximal effort determination. Between 53% and 63% of the participants who were classified as showing submaximal effort had Waddell signs. Waddell signs and submaximal effort were independent contributors to lifting performance. The contribution of submaximal effort was larger than that of Waddell signs, as shown by 20% to 29% higher explained variance in lifting performance when submaximal effort was added to the model first versus 3% to 6% higher explained variance when Waddell signs were added first.

LIMITATIONS

Assessor variability could have influenced the study results.

CONCLUSIONS

In people with chronic nonspecific low back pain, Waddell sign testing and determination of physical effort by observational criteria should not be used interchangeably to interpret lifting performance during FCE.

Reliability and Validity of Functional Capacity Evaluations: An Update

Functional capacity evaluations (FCEs) and other work-related assessments continue to be used in occupational rehabilitation to determine the capacity of injured and disabled workers to either return to their preinjury jobs, or to determine what they are capable of doing in a work context. New instruments have been developed and others refined. There is a continuing call however for these systems to demonstrate acceptable reliability and validity. Comprehensive reviews of reliability and validity of work-related assessments were published and included information up to the end of 1997. This study updates that information by examining research conducted on five FCEs over the subsequent 8-year period (January 1998–March 2006). The Isernhagen Work Systems (IWS) FCE had the most comprehensive coverage of all aspects of reliability and validity, while the Progressive Isoinertial Lifting Evaluation (PILE) was also extensively researched. Newer FCEs show promise and should continue to be investigated. Clinicians and others are encouraged to be informed consumers of the evidence that exists for the reliability and validity of FCEs and other work-related assessments.

Functional capacity evaluations for the prevention of occupational re-injuries in injured workers

BACKGROUND

Functional capacity evaluation (FCE) has been widely used to assess workers' physical state of readiness to return to work (RTW) after an injury and to make recommendations for the time and capacity in which they might return. FCEs are also used to prevent re-injury after RTW. Despite being a commonly used tool, little is known about how effective FCE is in preventing occupational injuries.

OBJECTIVES

To assess the effectiveness of FCE-based return to work recommendations in preventing occupational re-injuries of injured workers compared with no intervention or alternative interventions.

SEARCH STRATEGY

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 4), MEDLINE (1966 to December 2009), EMBASE (1980 to December 2009), CINAHL (1980 to December 2009), PsycINFO (1983 to December 2009) and PEDro (1929 to December 2009). The searches were not restricted by date, language or type of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of FCE-based return to work recommendations for preventing occupational re-injuries in injured workers.

DATA COLLECTION AND ANALYSIS

Four authors (NM, ES, JV, ML), in pairs, independently selected studies for inclusion, extracted data and assessed risk of bias.

MAIN RESULTS

We found no studies that compared FCE to no intervention. We found one RCT with 372 participants in which a short-form of one FCE was compared to the standard long-form FCE (Isernhagen Work Systems). Outcomes were recurrence rates of re-injuries. There was no significant difference between the two forms of FCE.We rated the overall quality of the evidence as low.

AUTHORS' CONCLUSIONS

There is no evidence for or against the effectiveness of FCE compared to no intervention. A short version of FCE showed similar effectiveness to a long version in preventing re-injury. More RCTs are needed.

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.

Can muscle soreness after intensive work-related activities be predicted?

OBJECTIVES

It is currently unknown whether specific determinants are predictive for developing delayed onset muscle soreness (DOMS) after heavy work-related activities. The aim of this study was to analyze whether personal characteristics and performance measures are predictive for onset, intensity, and duration of DOMS after performing work-related activities during a Functional Capacity Evaluation in healthy participants.

METHODS

Included in this study were 197 healthy participants (102 men, 95 women), all working within a broad range of professions. Five groups of predictors were tested in a multiple regression analysis model: personal variables, self-reported activity, self-reported health, perceived effort during the test, and objective outcomes of the test. Twenty-three independent variables were selected and tested with a backward regression analysis.

RESULTS

The onset of DOMS could be explained for 7% by the variables: sex and the work index of the Baecke questionnaire. Variance of intensity of DOMS could be explained for 13% by the variables: age, sex, and VO2max. Variance in duration of DOMS could be explained for 8% by the variables: sex and reported emotional role limitations. Onset, intensity, and duration of DOMS remain unpredictable for 87% or more.

CONCLUSIONS

The results demonstrate that the intensity and duration of self-reported DOMS can only minimally be predicted from the candidate predictors used in this study.

Validation of knowledge acquisition for surgical process models

OBJECTIVE

Surgical Process Models (SPMs) are models of surgical interventions. The objectives of this study are to validate acquisition methods for Surgical Process Models and to assess the performance of different observer populations.

DESIGN

The study examined 180 SPM of simulated Functional Endoscopic Sinus Surgeries (FESS), recorded with observation software. About 150,000 single measurements in total were analyzed.

MEASUREMENTS

Validation metrics were used for assessing the granularity, content accuracy, and temporal accuracy of structures of SPMs.

RESULTS

Differences between live observations and video observations are not statistically significant. Observations performed by subjects with medical backgrounds gave better results than observations performed by subjects with technical backgrounds. Granularity was reconstructed correctly by 90%, content by 91%, and the mean temporal accuracy was 1.8 s.

CONCLUSION

The study shows the validity of video as well as live observations for modeling Surgical Process Models. For routine use, the authors recommend live observations due to their flexibility and effectiveness. If high precision is needed or the SPM parameters are altered during the study, video observations are the preferable approach.

General and specific self-efficacy reports of patients with chronic low back pain: are they related to performances in a functional capacity evaluation?

INTRODUCTION

The objective of this study was to analyze the relationship of general and specific self-efficacy (SE) beliefs with functional capacity evaluation (FCE) performances in patients with chronic non-specific low back pain (CLBP), while controlling for influence of gender, age, and self-reported pain intensity, self-esteem, disability, psychosocial distress and health status.

METHODS

Included were 92 patients with CLBP referred to an outpatient university based multidisciplinary pain rehabilitation program in The Netherlands. All patients underwent an FCE. General SE was measured with the ALCOS questionnaire prior to the FCE, specific SE was measured with a self-constructed standardized question during the FCE. Paired samples t-tests were used to tests differences between predicted and actual performances. Pearson and Spearman rank correlation coefficients were used to express the strength of the relationships between SE and performances. Multivariate analyses were used to test the influence of control variables on the relationships between SE (general or specific) and performances.

RESULTS

Performances were consistently higher than patients' self-predictions. Differences between predictions and performances were significant in male lifting low, male carrying, and female carrying. With exception of the association between specific SE and lifting in males (r = 0.55, P < 0.05), all other correlations between general and specific SE and FCE performances were non-significant. Multivariable regression analyses showed that the relative contribution of SE measures over gender was little or none.

CONCLUSIONS

The contribution of specific SE to the prediction of FCE performances is moderate in one instance, and insignificant in most instances (both specific and general SE). Because of the consistency of the differences between prediction (specific SE) and performances, and depending on the level of accuracy needed, future research may deliberate the use of predicted material handling capacities at group level and correct for a systematic underprediction.

The physician-owned occupational health department

This article provides a process to evaluate the likelihood of establishing a financially viable occupational medicine program (OMP), and discusses opportunities in which the occupational medicine clinic can partner with employers to help them to reduce the occurrence of work-related injuries and provide a safer work environment. Not all germane topics are discussed-employers must address safety and ergonomic issues within the workplace as well as those that a successful OMP is designed to address. However, the OMP should be a readily available resource for any of these issues. Common occupational challenges and opportunities also are examined.

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 (FCE) 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 (CLBP).

METHODS

Two cross sectional observation studies were performed with two samples of patients with CLBP (study 1: n = 79; study 2: n = 58). Pain related fears were operationally defined as the score on the Tampa Scale of Kinesiophobia in study 1, and the Fear Avoidance Beliefs Questionnaire (FABQ) 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 (p < 0.05). 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.

Functional self-efficacy beliefs influence functional capacity evaluation

OBJECTIVES

The relationship between functional self-efficacy and Functional Capacity Evaluation (FCE) lift performance was examined in workers' compensation claimants' with low back pain.

METHODS

A cross-sectional design was used. Forty-two claimants with back pain and 38 subjects without back pain were enrolled. Subjects completed a measure of functional self-efficacy related specifically to lifting. Subjects also underwent FCE floor-to-waist, waist-to-overhead and horizontal lift testing. Potential confounders were also assessed including perceived disability, pain intensity, and self-rated health. Analysis included Pearson correlation and multivariable linear regression.

RESULTS

Higher functional self-efficacy beliefs were highly associated with better FCE performance on each of the lift items tested (r = 0.50-0.73). In multivariable analysis, the measure of functional self-efficacy remained independently associated with lift performance after controlling for potential confounders.

CONCLUSION

Functional self-efficacy beliefs appear to influence FCE lift performance. Strategies for altering functional self-efficacy beliefs and their resulting impact on patient functional performance and outcomes should be examined.

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.

Are functional capacity evaluations affected by the patient's pain?

Functional capacity evaluations (FCE) are comprehensive batteries of performance-based tests used commonly to inform return-to-work decisions for injured workers. As many people undergoing FCE have painful musculoskeletal conditions limiting their work ability, pain becomes a critical factor in the assessment of function. This paper considers the available literature related to the influence of pain on FCE, which clearly indicates FCEs are behavioral assessments influenced by pain intensity and other pain-related constructs. Increasing pain levels are consistently associated with reduced FCE performance levels. As such, for purposes of claims adjudication, FCE should not be considered a purely "objective" indicator of functional impairment independent of subject or evaluator perceptions. FCE may have some value for facilitating return-to-work or re-integrating chronically disabled workers into the workforce, although pain factors must be taken into consideration when making predictions about future work status. Shorter FCEs could potentially be as effective as more lengthy protocols.

Does functional capacity evaluation predict recovery in workers' compensation claimants with upper extremity disorders?

OBJECTIVES

Functional capacity evaluations (FCEs) are commonly used to determine return-to-work readiness and guide decision making following work related injury, yet little is known of their validity. The authors examined performance on the Isernhagen Work Systems' FCE as a predictor of timely and sustained recovery in workers' compensation claimants with upper extremity disorders. A secondary objective was to determine whether FCE is more predictive in claimants with specific injuries (that is, fracture) as compared to less specific, pain mediated disorders (that is, myofascial pain).

METHODS

The authors performed a longitudinal study of 336 claimants with upper extremity disorders undergoing FCE. FCE indicators were maximum performance during handgrip and lift testing, and the number of tasks where performance was rated below required job demands. Outcomes investigated were days receiving time-loss benefits (a surrogate of return to work or work readiness) in the year following FCE, days until claim closure, and future recurrence defined as whether benefits restarted, the claim reopened, or a new upper extremity claim was filed. Cox and logistic regression were used to determine the prognostic effect of FCE crudely and after controlling for potential confounders. Analysis was performed separately on claimants with specific and pain mediated disorders.

RESULTS

Most subjects (95%) experienced time-loss benefit suspension within one year following FCE. The one year recurrence rate was 39%. Higher lifting performance was associated with faster benefit suspension and claim closure, but explained little variation in these outcomes (r2 = 1.2-11%). No FCE indicators were associated with future recurrence after controlling for confounders. Results were similar between specific injury and less specific groups.

CONCLUSIONS

Better FCE performance was a weak predictor of faster benefit suspension, and was unrelated to sustained recovery. FCE was no more predictive in claimants with specific pathology and injury than in those with more ambiguous, pain mediated conditions.