Quantitative Measures of Physical Risk Factors Associated with Work-Related Musculoskeletal Disorders of the Elbow: A Systematic Review

A Novel IMU-Based System for Work-Related Musculoskeletal Disorders Risk Assessment

This study introduces a novel wearable Inertial Measurement Unit (IMU)-based system for an objective and comprehensive assessment of Work-Related Musculoskeletal Disorders (WMSDs), thus enhancing workplace safety. The system integrates wearable technology with a user-friendly interface, providing magnetometer-free orientation estimation, joint angle measurements, and WMSDs risk evaluation. Tested in a cable manufacturing facility, the system was evaluated with ten female employees. The evaluation involved work cycle identification, inter-subject comparisons, and benchmarking against standard WMSD risk assessments like RULA, REBA, Strain Index, and Rodgers Muscle Fatigue Analysis. The evaluation demonstrated uniform joint patterns across participants (ICC=0.72±0.23) and revealed a higher occurrence of postures warranting further investigation, which is not easily detected by traditional methods such as RULA. The experimental results showed that the proposed system's risk assessments closely aligned with the established methods and enabled detailed and targeted risk assessments, pinpointing specific bodily areas for immediate ergonomic interventions. This approach not only enhances the detection of ergonomic risks but also supports the development of personalized intervention strategies, addressing common workplace issues such as tendinitis, low back pain, and carpal tunnel syndrome. The outcomes highlight the system's sensitivity and specificity in identifying ergonomic hazards. Future efforts should focus on broader validation and exploring the relative influence of various WMSDs risk factors to refine risk assessment and intervention strategies for improved applicability in occupational health.

Empirical Suitability of Scoring Systems of Observational Techniques for Repetitive Movements Based on Discomfort

This study empirically investigated the effects of repetitive movements of body parts through an experiment, and evaluated the suitability of the scoring systems of the existing observational methods for repetitive movements, based on the experimental results. Eighteen healthy college students participated in the experiment to assess discomfort, wherein joint movement, its repetition, and external load were used as independent variables. Postural loads for 16 postures used in the experiment were assessed using rapid upper limb assessment (RULA) and loading on the entire body assessment (LEBA). Three independent variables, joint motion, its repetition, and external load, as well as the interaction between motion repetition and external load, had significant effects on discomfort. Joint motion and external load significantly affected the RULA grand score, whereas all three independent variables affected the LEBA score. This finding may indicate that LEBA more accurately reflects the effect of repetitive body part movements. Additionally, the scoring systems for repetitive back motions by quick exposure check (QEC) and for repetitive wrist motions via a risk assessment and management tool for manual handling proactively II (RAMP II) may be reasonable based on the results of this study. The findings of this study can be used as reference information for better evaluation of postural loads assessed using the existing observational techniques, and as useful baseline data for the development of a new observational method to accurately assess stress caused by repetitive movements.

Occupational health knowledge discovery based on association rules applied to workers' body parts protection: a case study in the automotive industry

Occupational Health Protection (OHP) is mandatory by law and can be accomplished by considering the participation of others besides occupational physicians. The data shared can originate knowledge that might influence other processes related to occupational risk prevention. In this study, we used Artificial Intelligence (AI) methods to extract patterns among records shared under these circumstances over two years in the automotive industry. Records featuring OHP data against physical working conditions were selected, and a database of 383 profiles was designed. As Occupational Health Protection profiles under study are associated with work functional ability reduction, the body part(s) (n = 14) where it occurred were identified. Association Rules (ARs) coupled with Natural Language Processing techniques were applied to find meaningful hidden relationships and to identify the occurrence of protection profiles being assigned to at least two body parts simultaneously. After filtering ARs using three metrics (support, confidence, and lift), 54 ARs were found. The distribution of simultaneous body parts is presented as being higher in Special projects (n = 5). The results can use in: (i) design a multi-site body parts functional work ability (loss) model; (ii) model the capacity of organizations to retain workers in their working settings and (iii) prevent work-related musculoskeletal symptoms.

A Clinical Overview of the Natural Course and Management of Lateral Epicondylitis

Lateral epicondylitis (LE), also often called tennis elbow, is a frequent cause of elbow pain. The most characteristic symptom of LE is pain and burning around the lateral epicondyle of the humerus that may radiate to the forearm or to the upper arm. Ultrasonography is a quick and noninvasive tool used to confirm (or exclude) the diagnosis of LE. Management of LE symptoms should be directed to the management of pain, protection of movement, and improvement of arm performance. Treatment of LE includes nonoperative techniques and surgery. [Orthopedics. 2023;46(4):e210-e218.].

The prevalence and risk factors of work related musculoskeletal disorders among electronics manufacturing workers: a cross-sectional analytical study in China

OBJECTIVES

To describe the prevalence of self-reported musculoskeletal disorders among workers in the electronics manufacturing industry and to investigate the relations between work-related musculoskeletal disorders (WMSDs) and work-related variables.

METHODS

An interview-based questionnaire survey was carried out in thirty electronics manufacturing factories in China in 2018. The prevalence of WMSDs was estimated using the modified Nordic Musculoskeletal Questionnaire (NMQ). A multivariate logistic regression model was applied to evaluate the effects of risk factors on WMSDs on multiple body parts.

RESULTS

The 12-month prevalence of WMSDs among participants was 40.6%, and the common body sites affected were the neck (26.8%), shoulder (22.8%), upper back (14.9%), and lower back (14.8%). The results of logistic regression showed that female adults, > 5 job tenure and work-related factors (including awkward posture, lifting or carrying weights, excessive repetition, prolonged sitting, monotonous work and working under conditions of cold or temperature variations) led to a higher risk of WMSDs on most body parts. Upper back, wrist/hand and elbow pain levels were significantly higher for workers with vibration. However, more frequently, physical exercise was a protective factor against WMSDs on most body parts except the upper back, leg and knee.

CONCLUSIONS

The study indicates a high prevalence of musculoskeletal pain among the electronics manufacturing industry in China. Different personal and work factors are related to the occurrence of WMSD on different body parts. Preventive measures should be implemented based on the characteristics of WMSD in the electronic manufacturing industry. Furthermore, the training and intervention guidance of ergonomic hazards in the workplace need to be strengthened by understanding the impact of bad posture, avoiding long-term sitting posture and increasing physical activities.

Digital Rehabilitation for Elbow Pain Musculoskeletal Conditions: A Prospective Longitudinal Cohort Study

Elbow musculoskeletal pain (EP) is a major cause of disability. Telerehabilitation has shown great potential in mitigating musculoskeletal pain conditions, but EP is less explored. This single-arm interventional study investigates clinical outcomes and engagement levels of a completely remote multimodal digital care program (DCP) in patients with EP. The DCP consisted of exercise, education, and cognitive-behavioral therapy for 8 weeks. Primary outcome: disability change (through the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), treatment response cut-offs: 12.0-point reduction and 30% change). Secondary outcomes: pain, analgesic intake, surgery intent, mental health, fear–avoidance beliefs, work productivity, and patient engagement. Of the 132 individuals that started the DCP, 112 (84.8%) completed the intervention. Significant improvements were observed in QuickDASH with an average reduction of 48.7% (11.9, 95% CI 9.8; 14.0), with 75.3% of participants reporting ≥30% change and 47.7% reporting ≥12.0 points. Disability change was accompanied by reductions in pain (53.1%), surgery intent (57.5%), anxiety (59.8%), depression (68.9%), fear–avoidance beliefs (34.2%), and productivity impairment (72.3%). Engagement (3.5 (SD 1.4) sessions per week) and satisfaction 8.5/10 (SD 1.6) were high. The significant improvement observed in clinical outcomes, alongside high engagement, and satisfaction suggests patient acceptance of this care delivery mode.

Evaluation of a New Simplified Inertial Sensor Method against Electrogoniometer for Measuring Wrist Motion in Occupational Studies

Wrist velocity is an important risk factor for work-related musculoskeletal disorders in the elbow/hand, which is also difficult to assess by observation or self-reports. This study aimed to evaluate a new convenient and low-cost inertial measurement unit (IMU)-based method using gyroscope signals against an electrogoniometer for measuring wrist flexion velocity. Twelve participants performed standard wrist movements and simulated work tasks while equipped with both systems. Two computational algorithms for the IMU-based system, i.e., IMU_norm and IMU_flex, were used. For wrist flexion/extension, the mean absolute errors (MAEs) of median wrist flexion velocity compared to the goniometer were <10.1°/s for IMU_norm and <4.1°/s for IMU_flex. During wrist deviation and pronation/supination, all methods showed errors, where the IMU_norm method had the largest overestimations. For simulated work tasks, the IMU_flex method had small bias and better accuracy than the IMU_norm method compared to the goniometer, with the MAEs of median wrist flexion velocity <5.8°/s. The results suggest that the IMU-based method can be considered as a convenient method to assess wrist motion for occupational studies or ergonomic evaluations for the design of workstations and tools by both researchers and practitioners, and the IMU_flex method is preferred. Future studies need to examine algorithms to further improve the accuracy of the IMU-based method in tasks of larger variations, as well as easy calibration procedures.

Development of modified rapid entire body assessment (MOREBA) method for predicting the risk of musculoskeletal disorders in the workplaces

Background

Rapid Entire Body Assessment (REBA) technique is one of the tools developed for predicting the risk of musculoskeletal disorders based on the effective risk factors. This method has several limitations. The present study was aimed to develop the Modified Rapid Entire Body Assessment (MOREBA) method to more accurately predict the risk of musculoskeletal disorders.

Materials

This cross-sectional study was performed on 300 male workers of a steel factory with a variety of job tasks in Iran. Then, the information related to the various physical risk factors was extracted through observation of their duties and conversation with them. Also, the subjects were asked to complete the Persian version of Cornell musculoskeletal discomfort questionnaires (CMDQ). Then, a theoretical model was drawn in AMOS software. Computed coefficients were used to develop the MOREBA equation. In the end, the final scores were categorized by ROC curves, and the validation of the novel method was investigated using linear regression analysis.

Results

The parameters evaluated in the MOREBA method included contact stress, rapid and sudden movement, throwing motion, hand-arm vibration, whole-body vibration, temperature, and work-rest cycle in addition to the parameters of the REBA method, including awkward posture, coupling, force, load, static activity, and repetitive activity. The results showed that the strain produced by the physical risk factors with the total effect coefficient of 0.783 could significantly affect the musculoskeletal symptoms. The computed coefficients of the risk factors were applied to develop a novel index. The final score of the MOREBA method was categorized into four levels by optimal cut-off points of 12.37, 16.51, and 24.35. Based on the results, the MOREBA and REBA methods could justify 67 and 55% of the variations of musculoskeletal symptoms, respectively.

Conclusions

The results revealed that modifications conducted in the REBA method were effective, and the MOREBA method can provide a more accurate prediction of the risk of musculoskeletal disorders.

Work-relatedness of lateral epicondylitis: Systematic review including meta-analysis and GRADE work-relatedness of lateral epicondylitis

Background

Lateral epicondylitis (LE) is a highly prevalent musculoskeletal disorder in workers, often associated with physically demanding work. Knowledge of work‐relatedness of LE is crucial to develop appropriate preventive measures. This study investigates the prospective association between work‐related physical risk factors and LE.

Methods

A systematic literature review was conducted in MedLine using PubMed from January 1, 2010 until February 16, 2021. Published reports were included if: (1) LE was clinically assessed, (2) exposure to work‐related physical risk factors was assessed, and (3) associations between LE and work‐related physical risk factors were reported in prospective studies. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation.

Results

In total, 318 workers with LE from a population of 5036 workers in five studies were included. Meta‐analyses revealed high‐quality evidence for associations between LE and a Strain Index (SI) score >5.1 (odds ratio [OR]: 1.75, 95% confidence interval (CI): 1.11–2.78) and moderate‐quality evidence for forearm rotation >4 h/day or forearm rotation ≥45° for ≥45% time (OR: 1.85, 95% CI: 1.10–3.10). Gripping, flexion and extension of the wrist, and repetitive movements showed no significant associations with LE.

Conclusion

High‐quality evidence was found indicating that a higher SI increased the risk of LE. Moderate‐quality evidence was found for an association between forearm rotation and LE. No associations were found between other physical risk factors and LE. Primary preventive interventions should focus on a reduction of the SI and of high forearm rotation in work.

Prevalence of Musculo-skeletal Discomfort and Level of Functional Limitations among Physiotherapists in Karachi City

Introduction: Musculoskeletal discomfort is one of the most prevalent muscular pain condition hindering normal activities reported by physical therapists and health care professionals generally engaged in handling and mobilizing patients. The study was conducted to find the prevalence of musculoskeletal discomfort and level of functional limitations in physiotherapists. Method: This research was questionnaire based cross sectional study conducted in Karachi city from January to April 2019.Data collection was completed from registered physical therapists employed in different institutions. Two questionnaires were filled by the physiotherapists. Questionnaire 01, including thirteen questions on functional activities of daily life which are potentially related to functional areas of Neck Disability Index (NDI). Questionnaire 02 was based on 1987 version of Nordic musculoskeletal questionnaire. Results: Participation of 80 physical therapists in the study.75% was directly involved with patient handling and 25% were teachers. A total of 35% therapists reported 7 days symptoms prevalence with a higher prevalence in cervical (77.1%), lower back (68.6%) and upper back (51.4%).Similarly 65% workers showed previous 12 month symptoms with higher prevalence in neck (72.3%). Gender prevalence of 7days and 12 months was high in female therapist. Conclusion: It has been concluded that 12 month prevalence of musculoskeletal discomfort was 65%, whereas 7 days was 35% and level of functional limitation from activities was insignificant. Keywords: Epidemiology, musculoskeletal discomfort, Severity, Physical therapy,

Effects of handle height and load on the endurance time for simulated demolition tasks

BACKGROUND

Manual demolition tasks are heavy physical demanding tasks which involve forceful exertion of sustained pushing. They result in muscle fatigue which could lead to musculoskeletal disorders. Assessments of maximum endurance time (MET) are essential in understanding the developing of muscle fatigue for these tasks.

OBJECTIVE

The objectives of this study were to determine the effects of handle height and load conditions on the MET, and to establish MET models for the simulated demolition tasks.

METHODS

Twenty three male participants performed simulated demolition tasks under three loads and three handle heights conditions until they could not do so any longer. Their METs and ratings of perceived exertion were recorded and analyzed.

RESULTS

The results showed that both load and handle height were significant (p < 0.0001) factors affecting the MET. Regression models to predict the MET under handle height and load conditions were established. The mean absolute deviations of these models were between 1.91 and 4.84 min.

CONCLUSION

The MET models established may be used to estimate the MET which may be adopted in work/rest arrangement for demolition tasks using a handheld demolition hammer.

Repetitive and forceful movements of the hand as predictors of treatment for pain in the distal upper extremities

Objective

To investigate repetitive movements and the use of hand force as causes of treatment for distal upper extremities musculoskeletal disorders

Methods

A cohort of 202 747 workers in a pension health scheme from 2005 to 2017 in one of 17 jobs (eg, office work, carpentry, cleaning) was formed. Representative electro-goniometric measurements of wrist angular velocity as a measure for repetition and expert-rated use of hand force were used in a job exposure matrix (JEM). Job titles were retrieved from the Danish registers. Outcome was first treatment in the distal upper extremities. In a Poisson regression model, incidence rate ratios (IRRs) of treatment were adjusted for age, calendar-year, diagnosis of rheumatoid arthritis and arm fractures. In further analyses, wrist velocity or hand force was added.

Results

In men, wrist velocity had an IRR of 1.48 (95% CI 1.15 to 1.91) when the highest exposure level was compared with the lowest but with no clear exposure-response pattern. The effect became insignificant when adjusted for hand force. Hand force had an IRR of 2.65 (95% CI 2.13 to 3.29) for the highest versus the lowest exposure with an exposure-response pattern, which remained after adjustment for wrist velocity. Among women, no increased risk was found for hand force, while wrist velocity showed a significantly protective association with treatment.

Conclusions

In men, occupational exposure to hand force more than doubled the risk of seeking treatment. The results for exposure to repetition were less clear. In women, we could not find any indications of an increased risk neither for force nor for repetition.

Risk of pain in the neck and shoulders and job change among hairdressers: a combined questionnaire and register-based Danish prospective cohort study

Objective

To investigate whether intensity of work as a hairdresser was associated with treatments for pain, and if musculoskeletal pain was associated with leaving the hairdressing trade.

Methods

We formed two cohorts of hairdressers covered in the PensionDanmark Health Scheme (PDHS). Cohort 1 consisted of 1304 active hairdressers in 2009. Self-reported weekly haircuts were used as work intensity measure and treatments for pain in the neck and shoulders in PDHS were used as outcome. We used a Cox regression model with robust sandwich estimates adjusted for age, sex, employment status and prior treatment < 1 year before July 2009. Cohort 2 consisted of all hairdressers ever covered in the PDHS from 2006 to 2016 (n = 11,162). Exposure were treatments in PDHS within the last year. Outcome was leaving the trade within the following year. Adjustments were made for sex, calendar-year and age in Cox regression models.

Results

The adjusted hazard ratio of treatments in PDHS compared to the lowest work intensity was 0.95 (95% CI 0.58–1.55) and 0.74 (0.43–1.29) for medium and highest intensity, respectively. The risk of leaving the trade was lower, HR 0.80 (0.72–0.90) among hairdressers with treatments in PDHS within the last year, mainly driven by hairdressers aged < 56 years.

Conclusion

We found no association between intensity of work as a hairdresser, measured as self-reported weekly haircuts, and treatments for pain in PDHS. Furthermore, we found a protective effect of treatments in the PDHS within the last year on risk of leaving the trade.

Epicondylopathia humeri radialis

BACKGROUND

Lateral epicondylitis is a common orthopaedic condition often massively restricting the quality of life of the affected patients. There are a wide variety of treatment options - with varying levels of evidence.

METHOD

The following statements and recommendations are based on the current German S2k guideline Epicondylopathia radialis humeri (AWMF registry number: 033 - 2019). All major German specialist societies participated in this guideline, which is based on a systematic review of the literature and a structured consensus-building process.

OUTCOMES

Lateral epicondylitis should be diagnosed clinically and can be confirmed by imaging modalities. The Guidelines Commission issues recommendations on clinical and radiological diagnostic workup. The clinical condition results from the accumulated effect of mechanical overload, neurologic irritation and metabolic changes. Differentiating between acute and chronic disorder is helpful. Prognosis of non-surgical regimens is favourable in most cases. Most cases spontaneously resolve within 12 months. In case of unsuccessful attempted non-surgical management for at least six months, surgery may be considered as an alternative, if there is a corresponding structural morphology and clinical manifestation. At present, it is not possible to recommend a specific surgical procedure.

CONCLUSION

This paper provides a summary of the guideline with extracts of the recommendations and statements of its authors regarding the pathogenesis, prevention, diagnostic workup as well as non-surgical and surgical management.

Investigating the Relationship between Body Mass Index and Pain in the Spine in Children or Adolescents: A Systematic Review

Background: Neck pain (NP), back pain (BP), and low back pain (LBP) are generally defined as "pain in the spine." With the increasing prevalence of childhood obesity, secondary problems such as pain in the spine have arisen. The purpose of this review was to investigate the relationship between body mass index (BMI) and pain in the spine in children or adolescents. Methods: Publications were searched in PubMed, Web of Science, Scopus, and Google Scholar databases up to December 12, 2020. The search strategy in the database consisted of free text words and MeSH terms. Results: Twelve studies were reviewed. It was determined that different methods were used in all 12 studies to evaluate pain. In the evaluation of overweight/obesity, these studies performed BMI assessment by dividing body weight in kilograms by height squared. Five studies showed a relationship between LBP and BMI, two studies showed a relationship between BP and BMI, and two studies showed a relationship between NP and BMI. Conclusions: The review shows that there is a relationship between BMI and pain in the spine, especially LBP. There may be factors affecting this condition such as mechanical loading and hormonal metabolic activity in childhood and adolescence. Different methods are used in the studies in literature for the assessment pain in the spine and BMI, overweight, and obesity.

Elbow tendinopathy and occupational biomechanical overload: A systematic review with best-evidence synthesis

OBJECTIVES

To evaluate the evidence of an association between occupational and non-occupational exposure to biomechanical risk factors and lateral elbow tendinopathy, medial elbow tendinopathy, and olecranon bursitis.

METHODS

We carried out a systematic review of the literature. We searched MEDLINE (up to November 2019) and checked the reference lists of relevant articles/reviews. We aimed to include studies where (a) the diagnosis was based on physical examination (symptoms plus clinical signs) and imaging data (if any); and (b) the exposure was evaluated with video analysis and/or direct measurements. A quality assessment of the included studies was performed along with an evaluation of the level of evidence of a causal relationship.

RESULTS

We included four studies in the qualitative synthesis: two prospective cohorts and two cross-sectional studies. All the included studies investigated "lateral/medial epicondylitis", albeit the diagnosis was not supported by imaging techniques. Two cohort studies suggested that a combination of biomechanical risk factors for wrist/forearm is associated with increased risk of "lateral epicondylitis". This association was not observed in the two included cross-sectional studies. The cohort studies suggested that a Strain Index score higher than 5 or 6.1 could double the risk of "lateral epicondylitis". No association with increased risk of "medial epicondylitis" was observed.

CONCLUSIONS

There is limited evidence of a causal relationship between occupational exposure to biomechanical risk factors and lateral elbow tendinopathy. For medial elbow tendinopathy, the evidence is insufficient to support this causal relationship. No studies on olecranon bursitis and biomechanical overload were identified.

Work Disabling Nerve Injury at Both Elbows Due to Laptop Use at Flexible Workplaces inside an Office: Case-Report of a Bilateral Ulnar Neuropathy

Background: This case report describes whether a female civil servant who developed bilateral ulnar neuropathy can be classified as having an occupational disease. Methods: The Dutch six-step protocol for the assessment and prevention of occupational diseases is used. Results: Based on the six-step protocol, we propose that pressure on the ulnar nerve in the elbow region precipitated the neuropathy for this employee while working prolonged periods in elbow flexion with a laptop. Conclusion: Despite the low incidence laptop use might be a risk factor for the occurrence of ulnar neuropathy due to prolonged pressure on the elbow. Employers and workers need to be educated about this disabling occupational injury due to laptop use and about protective work practices such as support for the upper arm and elbow. This seems especially relevant given the trend of more flexible workspaces inside and outside offices, and given the seemingly safe appearance of laptop use.

Ultrasonographic analysis of the extensor carpi radialis brevis in asymptomatic individuals

BACKGROUND

Tennis elbow is characteristically seen as damage at the extensor carpi radialis brevis (ECRB) on ultrasonography. In this study, damage at the origin of the ECRB was investigated using ultrasonography in elbows without complaints pertaining to the joint.

METHODS

We investigated 282 elbows on the dominant side in volunteers who consented to participate in the study and had no complaints or history of trauma to either elbow, no tenderness in the lateral epicondylar region on physical examination, and no pain upon resisted extension of the wrist and/or middle finger with the elbow extended (162 men, 120 women; mean age 62 years, range 21-84 years). On ultrasonography, damage at the origin of the ECRB was defined as low echo or disruption in fiber orientation. Comparison between groups with and without damage was performed based on age, sex, history of sports activity involving the upper extremity, and history of work involving loading of the upper extremity.

RESULTS

Of the 282 elbows, damage was noted in 60 (21.3%). Comparing the groups with and without damage, mean ages were 66.2 (40-80) years and 60.9 (21-84) years. The group with damage included 31 of 162 (18.1%) male elbows and 29 of 110 (26.4%) female elbows; 10 of 64 elbows (15.6%) had a positive history of sports involving the upper extremity and 50 of 218 elbows (22.9%) had no history; 16 of the 64 elbows (25.0%) had a positive history of work involving loading the upper extremity and 44 of the 218 elbows (20.2%) had no history. Age was significantly higher in the group with damage. The group with damage showed no significant differences in other categories.

CONCLUSIONS

Asymptomatic damage at the ECRB origin was noted in 21.3% of elbows at higher ages, but there was no association with sports or work.

Lateral epicondylitis: the condition and current management strategies

Lateral epicondylitis or tennis elbow is a common condition estimated to affect between 1 and 3% of adults. As a result of its high prevalence, both primary and secondary care physicians are frequently presented with this problem, so knowledge of its presentation and up-to-date management strategies is essential.

This review collates the most recent evidence on lateral epicondylitis to help the clinician perform assessments and make treatment decisions, based on the best current clinical practice.