Validity of self-reports of knee-straining activities at work: a field study with 6-month follow-up

Occupational risk factors for meniscal lesions: a systematic review and meta-analysis

BACKGROUND

Meniscal lesions are common and are associated with the development of knee osteoarthritis. Knee-straining activities at work such as kneeling or squatting cause high biomechanical stresses on the knee joints that can lead to acute or chronic injuries. The objective of this systematic review is to update the evidence on the potential relationship between occupational risk factors and meniscal lesions.

METHODS

We searched the Medline, Embase and Web of Science databases until August 2021 to identify epidemiological observational studies on the association between occupational risk factors and meniscal lesions. Study selection, data extraction and risk of bias assessment were performed independently by two reviewers. Effect measures were extracted from individual studies and pooled with random effects meta-analysis. Heterogeneity analyses were conducted. We used GRADE (Grades of Recommendations, Assessment, Development and Evaluation) to assess the overall quality of evidence.

RESULTS

The database search resulted in 11,006 references, and 46 additional studies were identified through hand search. Twenty-two studies (represented in 25 publications) met the predefined eligibility criteria and nine records were included in the meta-analysis. There was only one study with an overall low risk of bias. Significant associations between occupational risk factors and the development of meniscal lesions were found for kneeling (effect size (ES) 2.15, 95% CI 1.67-2.76), squatting (ES 2.01, 95% CI 1.34-3.03), climbing stairs (ES 2.28, 95% CI 1.58-3.30), lifting and carrying weights ≥ 10 kg (ES 1.63, 95% CI 1.35-1.96), lifting and carrying weights ≥ 25 kg (ES 1.56, 95% CI 1.08-2.24), playing football on a professional level (ES 5.22, 95% CI 3.24-8.41), working as a hard coal miner (ES 5.23, 95% CI 2.16-12.69) and floor layers (ES 1.99, 95% CI 1.43-2.78). The overall quality of evidence according GRADE was moderate to low.

CONCLUSION

We found consistent evidence of an increased risk of meniscal lesions by occupational knee-straining exposures. Our findings are important for the development of preventive strategies to reduce work-related knee disorders and work absence.

TRIAL REGISTRATION

PROSPERO (registration no. CRD42020196279 ).

Detection of kneeling and squatting during work using wireless triaxial accelerometers

Occupational kneeling and squatting are well-documented risk factors for knee disorders. A method using 3 wireless accelerometers to detect and discriminate kneeling and squatting during work were developed based on data from a semi-standardised laboratory protocol. The method was tested for validity under free-living working conditions. The developed method showed high sensitivity (88-99%) and specificity (98-99%) for detection of kneeling and squatting during the semi-standardised laboratory conditions. During free-living working conditions, kneeling showed very high sensitivity (94%) and specificity (99%), while squatting results were non-conclusive due to limited duration of squatting during the free-living working conditions. This method shows great promise for long-term technical measurement of kneeling and squatting during normal working conditions using wireless accelerometers. The method opens up possibilities for using technical measurements to provide valid exposure assessments and intervention evaluations of kneeling and squatting, as well as increased feasibility for technical measurements in large cohort studies. Practitioner summary: Quantification of kneeling and squatting during work is important for prevention, but limited by either imprecise or costly methods. This study developed and validated an inexpensive wireless accelerometer-based measurement method that can be used by practitioners and researchers for long-term measurements of kneeling and squatting during free-living working conditions.

Deviation between self-reported and measured occupational physical activity levels in office employees: effects of age and body composition

OBJECTIVES

Whether occupational physical activity (PA) will be assessed via questionnaires or accelerometry depends on available resources. Although self-reported data collection seems feasible and inexpensive, obtained information could be biased by demographic determinants. Thus, we aimed at comparing self-reported and objectively measured occupational sitting, standing, and walking times adjusted for socio-demographic variables.

METHODS

Thirty-eight office employees (eight males, 30 females, age 40.8 ± 11.4 years, BMI 23.9 ± 4.2 kg/m(2)) supplied with height-adjustable working desks were asked to report sitting, standing, and walking times using the Occupational Sitting and Physical Activity Questionnaire during one working week. The ActiGraph wGT3X-BT was used to objectively measure occupational PA during the same week. Subjectively and objectively measured data were compared computing the intra-class correlation coefficients, paired t tests and Bland-Altman plots. Furthermore, repeated-measurement ANOVAs for measurement (subjective vs. objective) and socio-demographic variables were calculated.

RESULTS

Self-reported data yielded a significant underestimation of standing time (13.3 vs. 17.9%) and an overestimation of walking time (12.7 vs. 5.0%). Significant interaction effects of age and measurement of standing time (F = 6.0, p = .02, ηp(2) = .14) and BMI group and measurement of walking time were found (F = 3.7, p = .04, ηp(2) = .17). Older employees (>39 years) underestimated their standing time, while underweight workers (BMI < 20 kg/m(2)) overestimated their walking time.

CONCLUSIONS

Self-reported PA data differ from objective data. Demographic variables (age, BMI) affect the amount of self-reported misjudging of PA. In order to improve the validity of self-reported data, a correction formula for the economic assessment of PA by subjective measures is needed, considering age and BMI.

Factors affecting the perception of whole-body vibration of occupational drivers: an analysis of posture and manual materials handling and musculoskeletal disorders

Due to the high cost of conducting field measurements, questionnaires are usually preferred for the assessment of physical workloads and musculoskeletal disorders (MSDs). This study compares the physical workloads of whole-body vibration (WBV) and awkward postures by direct field measurements and self-reported data of 45 occupational drivers. Manual materials handling (MMH) and MSDs were also investigated to analyse their effect on drivers' perception. Although the measured values for WBV exposure were very similarly distributed among the drivers, the subjects' perception differed significantly. Concerning posture, subjects seemed to estimate much better when the difference in exposure was significantly large. The percentage of measured awkward trunk and head inclination were significantly higher for WBV-overestimating subjects than non-overestimators; 77 and 80% vs. 36 and 33%. Health complaints in terms of thoracic spine, cervical spine and shoulder-arm were also significantly more reported by WBV-overestimating subjects (42, 67, 50% vs. 0, 25, 13%, respectively). Although more MMH was reported by WBV-overestimating subjects, there was no statistical significance in this study.

PRACTITIONER SUMMARY

Self-reported exposures of occupational drivers are affected by many other cofactors, and this can result in misinterpretations. A comparison between field measurement and questionnaire was used to highlight the factors affecting the perception of drivers for whole-body vibration (WBV) exposure. Posture and musculoskeletal disorders influenced the perception of the similarly WBV-exposed drivers significantly.

Medical work assessment in German hospitals: a study protocol of a movement sequence analysis (MAGRO-MSA)

Background

Medical doctors are essential for the German public and occupational health system. They ensure the productivity of German society by enabling people to regain and recover their health. That is why the physicians’ health and hence their productivity require special attention. Musculoskeletal disorders have a high prevalence in this work area. As a consequence, movement sequences, range of motions, and body postures of physicians in the course of the working day are in focus of this research project.

Methods

For this investigation 21 male or female junior physicians of various conservative medical disciplines will be covered. Data will be collected over one working day (approx. 9 hours). The CUELA system attached to the test person’s body detects body posture and/or movements. This biomechanical measurement system ensures a locomotor and posture analysis that includes movement sequences, movement intensity, and range of motions to qualify the work tasks. For data analysis intra- and inter-professional comparisons are chosen.

Conclusions

Working movement sequence analysis of physicians by means of the CUELA system is exclusive and novel in its focus. Up to now, knowledge of the working tasks of medical doctors has only been acquired by real-time observation approaches to work activity. In addition to this method of analysis, the CUELA system is able to record quantified biomechanical data about musculoskeletal loads of ordinary working tasks. Workloads and activities of physicians can be improved by ergonomic work design to reduce musculoskeletal disorders by utilizing the data collected. The healthcare system in Germany will thus be optimized by improving medical doctors’ health. Consequently, MAGRO-MSA will also be used for other healthcare professions such as nurses and physicians assistants.

Self-reported physical work exposures and incident carpal tunnel syndrome

BACKGROUND

To prospectively evaluate associations between self-reported physical work exposures and incident carpal tunnel syndrome (CTS).

METHODS

Newly employed workers (n = 1,107) underwent repeated nerve conduction studies (NCS), and periodic surveys on hand symptoms and physical work exposures including average daily duration of wrist bending, forearm rotation, finger pinching, using vibrating tools, finger/thumb pressing, forceful gripping, and lifting >2 pounds. Multiple logistic regression models examined relationships between peak, most recent, and time-weighted average exposures and incident CTS, adjusting for age, gender, and body mass index.

RESULTS

710 subjects (64.1%) completed follow-up NCS; 31 incident cases of CTS occurred over 3-year follow-up. All models describing lifting or forceful gripping exposures predicted future CTS. Vibrating tool use was predictive in some models.

CONCLUSIONS

Self-reported exposures showed consistent risks across different exposure models in this prospective study. Workers' self-reported job demands can provide useful information for targeting work interventions.

Does the association between musculoskeletal pain and sickness absence due to musculoskeletal diagnoses depend on biomechanical working conditions?

AIM

To investigate single-site and multi-site musculoskeletal pain as predictors of future sickness absence due to musculoskeletal disorders (MSD) among blue-collar employees in food industry, and to study to what extent this relationship depends on physical loading at work.

METHODS

Survey responses of 901 employees on working conditions and musculoskeletal pain during the past week were linked to their future sickness absence records obtained from the personnel register of a food industry company. Negative binomial regression models were computed to determine associations of pain in one and in multi-site with the number of sickness absence days due to MSD during a four-year follow-up. Analyses were made in the whole cohort and stratified by the occurrence of repetitive movements and awkward postures (low/high).

RESULTS

Multi-site pain occurred among 59 % in the total cohort and predicted sickness absence with a rate ratio of 1.48 [95 % confidence interval (CI) 1.21-1.80], adjusted for age, gender, biomechanical and psychosocial working conditions, body mass index and physical exercise. Similar associations were seen in the sub-cohorts with a low occurrence of repetitive movements (RR 2.18, CI 1.69-2.80) and awkward postures (RR 1.78, CI 1.39-2.28), but not in the sub-cohorts with a high occurrence of these exposure. Single-site pain was not predictive of sickness absence.

CONCLUSIONS

A very high level of sickness absence in biomechanically strenuous work was found. Multi-site pain predicted sickness absence due to MSD among the employees with low exposure, but not among those with high exposure.

Occupational kneeling and squatting: development and validation of an assessment method combining measurements and diaries

Objectives

As knee-straining postures such as kneeling and squatting are known to be risk factors for knee disorders, there is a need for effective exposure assessment at the workplace. Therefore, the aim of this study was to develop a method to capture knee-straining postures for entire work shifts by combining measurement techniques with the information obtained from diaries, and thus avoiding measuring entire work shifts. This approach was applied to various occupational tasks to obtain an overview of typical exposure values in current specific occupations.

Methods

The analyses were carried out in the field using an ambulatory measuring system (CUELA) to assess posture combined with one-day self-reported occupational diaries describing the durations of various work tasks. In total, 242 work shifts were measured, representing 81 typical tasks from 16 professions. Knee-straining postures were analysed as daily time intervals for five different postures. The accuracy of the method was examined by comparing the results to measurements of entire work shifts.

Results

Unsupported kneeling was the most widely used knee posture in our sample (median 11.4 % per work shift), followed by supported kneeling (3.0 %), sitting on heels (1.1 %), squatting (0.7 %), and crawling (0.0 %). The daily time spent in knee-straining postures varied considerably, both between the individual occupations, within an occupation (e.g. parquet layers: 0.0–88.9 %), and to some extent even within a single task (e.g. preparation work of floor layers (22.0 ± 23.0 %). The applied measuring method for obtaining daily exposure to the knee has been proven valid and efficient randomly compared with whole-shift measurements (p = 0.27).

Conclusions

The daily degree of postural exposure to the knee showed a huge variation within the analysed job categories and seemed to be dependent on the particular tasks performed. The results of this study may help to develop an exposure matrix with respect to occupational knee-straining postures. The tested combination of task-based measurement and diary information may be a promising option for providing a cost-effective assessment tool.