Low Back Musculoskeletal Disorders Research Articles

A Video-based Lifting Action Recognition Using Rank-Altered Kinematic Feature Pairs

Low-back musculoskeletal disorders (MSDs) are the primary work-related injuries among manual material handling (MMH) workers, who are frequently exposed to repetitive lifting. To prevent low-back MSDs in the workplace, we present a video-based lifting action recognition method using rank-altered kinematic feature pairs, called top-scoring pairs (TSPs). We derive TSPs from a video dataset containing lifting and other activities commonly seen in MMH. These TSPs collectively classify each frame as lifting and non-lifting. The validation process involves evaluating classification performance. The proposed method minimizes computational and memory requirements while achieving performance comparable to more complex methods with greater computational demands. This makes it suitable for systems with limited hardware resources, thereby providing extensive feasibility across a variety of MMH environments to improve workplace safety.

Comparison of multi-task ergonomic assessment methods for risk of upper extremity and low back musculoskeletal disorders

Work-related musculoskeletal disorder of upper extremity multi-task assessment methods (Revised Strain Index [RSI], Distal Upper Extremity Tool [DUET]) and manual handling multi-task assessment methods (Revised NIOSH Lifting Equation [RNLE], Lifting Fatigue Failure Tool [LiFFT]) were compared. RSI and DUET showed a strong correlation (rs = 0.933, p < 0.001) where increasing risk factor exposure resulted in increasing outputs for both methods. RSI and DUET demonstrated fair agreement (κ = 0.299) in how the two methods classified outputs into risk categories (high, moderate or low) when assessing the same tasks. The RNLE and LiFFT showed a strong correlation (rs = 0.903, p = 0.001) where increasing risk factor exposure resulted in increasing outputs, and moderate agreement (κ = 0.574) in classifying the outputs into risk categories (high, moderate or low) when assessing the same tasks. The multi-task assessment methods provide consistent output magnitude rankings in terms of increasing exposure, however some differences exist between how different methods classify the outputs into risk categories.

Study on a Bayes evaluation of the working ability of petroleum workers in the Karamay region, Xinjiang, China.

ObjectivesUse Bayes statistical methods to analyze the factors related to the working ability of petroleum workers in China and establish a predictive model for prediction so as to provide a reference for improving the working ability of petroleum workers.Materials and methodsThe data come from the health questionnaire database of petroleum workers in the Karamay region, Xinjiang, China. The database contains the results of a health questionnaire survey conducted with 4,259 petroleum workers. We established an unsupervised Bayesian network, using Node-Force to analyze the dependencies between influencing factors, and established a supervised Bayesian network, using mutual information analysis methods (MI) to influence factors of oil workers’ work ability. We used the Bayesian target interpretation tree model to observe changes in the probability distribution of work ability classification under different conditions of important influencing factors. In addition, we established the Tree Augmented Naïve Bayes (TAN) prediction model to improve work ability, make predictions, and conduct an evaluation.Results(1) The unsupervised Bayesian network shows that there is a direct relationship between shoulder and neck musculoskeletal diseases, anxiety, working age, and work ability, (2) The supervised Bayesian network shows that anxiety, depression, shoulder and neck musculoskeletal diseases (Musculoskeletal Disorders, MSDs), low back musculoskeletal disorders (Musculoskeletal Disorders, MSDs), working years, age, occupational stress, and hypertension are relatively important factors that affect work ability. Other factors have a relative impact on work ability but are less important.ConclusionAnxiety, depression, shoulder and neck MSDs, waist and back MSDs, and length of service are important influencing factors of work ability. The Tree Augmented Naïve Bayes prediction model has general performance in predicting workers’ work ability, and the Bayesian model needs to be deepened in subsequent research and a more appropriate forecasting method should be chosen.

A computer vision-based lifting task recognition method

Low-back musculoskeletal disorders (MSDs) are major cause of work-related injury among workers in manual material handling (MMH). Epidemiology studies show that excessive repetition is one of major risk factors of low-back MSDs. Thus, it is essential to monitor the frequency of lifting tasks for an ergonomics intervention. In the current field practice, safety practitioners need to manually observe workers to identify their lifting frequency, which is time consuming and labor intensive. In this study, we propose a method that can recognize lifting actions from videos using computer vision and deep neural networks. An open-source package OpenPose was first adopted to detect bony landmarks of human body in real time. Interpolation and scaling techniques were then applied to prevent missing points and offset different recording environments. Spatial and temporal kinematic features of human motion were then derived. These features were fed into long short-term memory networks for lifting action recognition. The results show that the F1-score of the lifting action recognition is 0.88. The proposed method has potential to monitor lifting frequency in an automated way and thus could lead to a more practical ergonomics intervention.

A Cross-Sectional Descriptive Study of Musculoskeletal Disorders (MSDs) of Male Shipbuilding Workers and Factors Associated the Neck, Shoulder, Elbow, Low Back, or Knee MSDs

This study investigates the cross-sectional descriptive characteristics of male shipbuilding workers’ musculoskeletal disorders (MSDs) and factors associated with MSDs in the neck, shoulders, elbows, low back, or knees. From the national compensation data confirmed as MSDs during three years between 2015 and 2017, 985 male workers were analyzed in terms of age, work experience, occupations, company size, and MSD type according to each body region. In the analysis of frequency and severity according to ‘occupation–body region–MSD type’, ‘Electrician/plumber–low back–herniated disc’ (6.9%) was the form of MSDs with the highest frequency among total MSDs, and ‘Crane–neck–herniated disc’ (500.5 days) was the highest mean of sick leave days. The low back MSDs (28.9%) were the highest frequency, followed by shoulders (27.7%) and knees (16.2%). The herniated disc was frequent in the neck and lumbar region, and the mean of sick leave days of the neck herniated disc (402.2 days) was greater than that of the low back herniated disc (321.1 days). While a rupture was frequent in the shoulder or knee region, the mean of sick leave days for shoulder rupture (335.1 days) was greater than that of the knee rupture (318.8 days). In the binary logistic regression analysis, age was positively associated with MSDs in the neck, shoulder, or elbow regions, while the low back MSDs category was not positively associated with age. Large companies with &gt;1000 employees were highly associated with neck MSDs, while small companies with &lt;30 employees were related to the low back MSDs. This study derives the characteristics for frequency and sick leave days of MSDs in the neck, shoulders, elbows, low back, or knees to prioritize MSD prevention information. The results of this study can be used as primary data for establishing MSD prevention policy.

A computer-vision method to estimate joint angles and L5/S1 moments during lifting tasks through a single camera

Weight lifting is a risk factor of work-related low-back musculoskeletal disorders (MSD). From the ergonomics perspective, it is important to measure workers’ body motion during a lifting task and estimate low-back joint moments to ensure the low-back biomechanical loadings are within the failure tolerance. With the recent development of advanced deep neural networks, an increasing number of computer vision algorithms have been presented to estimate 3D human poses through videos. In this study, we first performed a 3D pose estimation of lifting tasks using a single RGB camera and VideoPose3D, an open-source library with a fully convolutional model. Joint angle trajectories and L5/S1 joint moment were then calculated following a top-down inverse dynamic biomechanical model. To evaluate the accuracy of the computer-vision-based angular trajectories and L5/S1 joint moments, we conducted an experiment in which participants performed a variety of lifting tasks. The body motions of the participants were concurrently captured by an RGB camera and a laboratory-grade motion tracking system. The body joint angles and L5/S1 joint moments obtained from the camera were compared with those obtained from the motion tracking system. The results showed a strong correlation (r > 0.9, RMSE < 10°) between the two methods for shoulder flexion, trunk flexion, trunk rotation, and elbow flexion. The computer-vision-based method also yielded a good estimate for the total L5/S1 moment and the L5/S1 moment in the sagittal plane (r > 0.9, RMSE < 20 N·m). This study showed computer vision could facilitate safety practitioners to quickly identify the jobs with high MSD risks through field survey videos.

Prevalence and Work-Related Factors Associated with Lower Back Musculoskeletal Disorders in Female Shellfish Gatherers in Saubara, Bahia-Brazil.

Lower back musculoskeletal disorders (MSDs) are an important public health problem and the leading cause of disability worldwide, but with yet unknown prevalence among shellfish gatherers. To investigate the prevalence and work-related factors associated with lower back MSD in a population of female shellfish gatherers, an epidemiological cross-sectional study was carried out in Saubara, Bahia-Brazil, in 2013. The Brazilian version of the Job Content Questionnaire (JCQ) and the Nordic Musculoskeletal Questionnaire (NMQ), in addition to a questionnaire containing the physical demands adapted to the artisanal work, were applied to a random sample of 209 female shellfish gatherers. The prevalence of lower back MSD was 72.7%. Using multivariate logistic regression, the shellfish gatherers who had worked for more than 26 years in the activity showed a prevalence of 1.22 (95% CI: 1.04–1.44) times higher compared to those unexposed. Lower back MSD was 1.24 (95% CI: 1.08–1.42) times higher among those more exposed to work sitting with trunk flexion. Those performed manual handling and muscle force with the arms had a prevalence ratio of 1.18 (95% CI: 1.01–1.39). These results show the need for greater awareness of health and social welfare factors impacting workers in small-scale fisheries and will promote the elaboration of health care policies for this occupational class.

Monitoring and Evaluation of Whole-Body Vibration Exposure of Equipment Operators and Assessment of Associated Health Risk in an Indian Underground Pb-Zn Mine

Exposure to whole-body vibration (1-80 Hz) manifest in higher incidences of low back pain and other musculoskeletal disorders among the workforce in mining industry. The aim of the study was to determine the vibration intensity of twelve mining equipments which are regularly deployed in an underground mine and to evaluate the long term health risk of their operators as per ISO 2631-1:1997 guidelines. It was observed that the low profile dump trucks (LPDT) and load haul dumpers (LHD) had x axis (front-back) as dominant axis of vibration. The operators of LPDTs and LHDs had moderate health risk considering frequency weighted root mean square (r.m.s.) acceleration values of vibration (0.46 – 1.01 m/s2) and corresponding daily exposure of about 6 hours in a shift. Operators of three equipments i.e. water sprinkler, utility vehicle and backfill material carrier had high health risk with z (vertical) as dominant axis of vibration. RMS acceleration values were comparatively high (1.30- 1.96 m/s2) even though their duration of exposure was less (2.5-5.0 hours). Motor grader operator had minimal health risk from vibration exposure while rest two operators of explosive and personnel carrier had moderate health risk. Additional assessment of health risk was carried out using total vibration dose values wherever applicable. High health risks were attributed to fast and harsh driving, poor seat condition and absence of independent seat suspension. Besides technical and operational modifications, training programs should be organised to improve the awareness of this hazard among miners in India.

Ageing well with chronic musculoskeletal pain: protocol for a systematic review of non-pharmacological interventions aimed at reducing pain in an ageing population

Background: Chronic musculoskeletal pain in the elderly is highly prevalent, with osteoarthritis, low back pain, neck pain and other musculoskeletal disorders as the leading contributors to pain chronicity and disability. Previous reviews identifying effective components of non-pharmacological interventions for treating chronic pain have either few studies or the included studies examine outcome over a limited time span. This systematic review will investigate the effectiveness and components of interventions associated with management of chronic musculoskeletal pain in older adults (≥65 years).Methods/Design: This systematic review will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Randomised controlled trials of non-pharmacological interventions aimed at reducing pain in older adults with chronic musculoskeletal pain will be included. Articles will be identified through a comprehensive search of the following databases: Ovid MEDLINE, Embase, CINAHL, AMED, Scopus, Web of Science and PEDro. Two review authors will independently screen articles retrieved from the search for eligibility, and extract relevant data on methodological issues. A narrative synthesis will be completed if there are insufficient data for a meta-analysis. The narrative synthesis will summarise the current state of knowledge, interventions, study designs and robustness of evidence.Discussion: Findings of the study will inform support programs and interventions to assist people aging with pain, carers and other supporters and practitioners.Systematic review registration: PROSPERO 2017:CRD42017074173.

Optimization of Automotive Suspension System by Design of Experiments: A Nonderivative Method

A lot of health issues like low back pain, digestive disorders, and musculoskeletal disorders are caused as a result of the whole body vibrations induced by automobiles. This paper is concerned with the enhancement and optimization of suspension performance by using factorial methods of Design of Experiments, a nonderivative method. It focuses on the optimization of ride comfort and determining the parameters which affect the suspension behavior significantly as per the guidelines stated in ISO 2631-1:1997 standards. A quarter car test rig integrated with a LabVIEW based data acquisition system was developed to understand the real time behavior of a vehicle. In the pilot experiment, only three primary suspension parameters, that is, spring-stiffness, damping, and sprung mass, were considered and the full factorial method was implemented for the purpose of optimization. But the regression analysis of the data obtained rendered a very low goodness of fit which indicated that other parameters are likely to influence the response. Subsequently, steering geometry angles, camber and toe and tire pressure, were included in the design. Fractional factorial method with six factors was implemented to optimize ride comfort. The resultant optimum combination was then verified on the test rig with high correlation.

Work-related musculoskeletal disorders of the upper extremity with reference to working posture of secretaries

INTRODUCTION: This study investigated the prevalence of work related musculoskeletal disorders (WMSDs) of the upper extremity and low back among secretaries in a state public service and their associations with working posture. METHODOLOGY: A cross sectional survey was carried out among 150 secretaries randomly selected within the Lagos State Civil Service Secretariat, Ikeja, Lagos, Nigeria, by using a 52-item questionnaire which captured information on work related musculoskeletal disorders (WMSDs). Working posture was assessed by measuring the variation in craniovertebral angle (CVA) and using Rapid upper limb assessment (RULA) scores of participants. RESULTS: The prevalence of WMSDs of low back, neck, shoulder and hand of the participants in this study was observed to be 71.3%, 59.3%, 48.0% and 28.0% respectively The results of this study showed a significant difference in CVA and the RULA scores (p = 0.02), between participants with neck pain and those without neck pain, hand pain and those without hand pain (p = 0.003), low back pain and those without low back pain (p = 0.004. CONCLUSION: This study shows a high prevalence of upper extremity and low back musculoskeletal disorders among secretaries in Lagos State Civil Service Secretariat, Ikeja, Lagos Nigeria. Neither CVA nor RULA scores were associated with shoulder pain. Key words: Occupational Health, Cranio vertebral angle, Rapid upper limb assessment, Musculoskeletal discomfort

0393 Epidemiology of low back pain among nurses of the hospital of Sétif (Algeria)

ObjectivesIdentifying risk factors and quantification of the prevalence of low back pain among nurses and service agents working at the hospital in Sétif (Algeria).MethodA questionnaire containing 45 items was submitted...

Back pain among paramedics: a pilot study.

The back pain is one of the most prevalent health problems, and about 60-80% of people encounter with the same problem at least once in their whole life time (1). Several studies have shown that some healthcare workers are at high risk of musculoskeletal disorders, particularly low back pain (2). The Nurses and paramed-ic staffs, especially ambulance paramedics who work in prehospital emergency medical system (PEMS), are at high risk of back pain due to the nature of their services, encountering stressful conditions, strenuous physical activities such as handling patients, bad work environ-ment, and long-time standing (3-5). Additionally, ambu-lance paramedics are vulnerable to physical disorders that cause back pain not only because they involve in caring, handling injured patients, and transporting pa-tients with acute or chronic disorders, but also should work under abnormal circumstance such as the scene of accidents, natural disasters, and the confined space in the ambulance. However, few studies are available on the prevalence of low back pain and musculoskeletal disorders among ambulance paramedics, but no study on this important issue is available from Iran. There-fore, this study aimed to investigate the rate of low back pain and the contributory factors among ambulance paramedics who worked in the PEMS of Kashan, a city in the central region of Iran, in May 2012. A descriptive study was conducted on all ambulance paramedics in the PEMS of Kashan. A questionnaire was used for data collection. This questionnaire consisted of questions re -garding demographic features, and levels of psycholog -ical, social and job related stress as well as the stress re-lated to the work environment. Content validity of the questionnaire was confirmed by five faculty members in the Faculty of Nursing and two officials of the PEMS. Also the reliability of the questionnaire confirmed us-ing test-retest on five paramedics (r = 0.73 to 0.81 for different parts). A total of 68 questionnaires were dis-tributed among paramedics and 55 questionnaires were returned. Seven questionnaires were excluded as they were responded incompletely, finally 48 question-naires were analyzed. To analyze the data, descriptive statistics, chi-square tests and student’s t-tests were used. Half of the participants were graduated nurses, working in PEMS and the others were technicians in emergency medicine. In total, 79.17% of the participants had experienced at least one episode of low back pain in the last six months from the time of data collection. Although nearly 90% of participants expressed that they know the correct manner of transporting a patient with a stretcher and a long backboard, 47.37% of the back pains have been occurred after lifting and transport-ing heavy objects or patients. Significant relationships were observed between low back pain and work experi-ence (P = 0.025), body mass index (P = 0.001), job dissat-isfaction (P = 0.04), level of work-related psychological stressors, and fatigue due to overwork (P = 0.01). The low back pain was not related to the levels of impatience and depressed mood (P = 0.256), levels of qualification (P = 0.872), and anxiety in the workplace (P = 0.7). The re -sults of this study showed that low back pain is a serious problem which is prevalent among paramedics of the PEMS. This may affect their efficiency and quality of life. Lifting heavy patients was the most common cause of back pain. Also the study showed that the mental condi-tion of the participants plays a significant role in their low back pain. Therefore, the authorities should pay at-tention to the education of the paramedics about the ergonomics. Moreover establishing workplace assess-ment program, rehabilitation, refreshing, and stress reducing strategies should be considered.

The need for novel strategies to analyze the dynamic pattern of worker’s health over time and the consequences for sustained employability

The need for novel strategies to analyze the dynamic pattern of worker’s health over time and the consequences for sustained employability

Medical Utility of near Infrared Spectroscopy in Low Back Musculoskeletal Health and Disorders

The potential application of near infrared (NIR) spectroscopy has opened doors for many research investigations related to occupational health, specifically in low back muscle research. This review addressed haemodynamic measurements of paraspinal muscles within the context of low back musculoskeletal health and disorders. Systematic online English language searches were conducted using MEDLINE, EMBASE, Science Direct and Scopus. A study was included if it was focused on NIR spectroscopy application to the back region and was also published in the English language. A study was excluded if the main focus was either on upper/lower extremity specific investigations, or the experimental protocol was ambiguous, or the measures utilised were other than spectroscopy-derived haemodynamics. In total, 37 low back studies were included in the review. Studies were mainly classified into five categories: (i) postural variation, (ii) occupational exposure, (iii) aetiology of low back disorders, (iv) analysis of adipose tissue thickness on spectroscopy-derived measurements and (v) reliability of optical spectroscopy measurements. Seventeen studies were focused on the basic (patho) physiology of the low back musculature during a variety of postural variations. Thirteen studies were specific to occupational activities, whereas 10 investigations were related to low back musculoskeletal disorders. Nine studies examined the influence of adipose tissue thickness measured at the erector spinae region on haemodynamic responses. Reliability of spectroscopy-derived responses was reported in 10 studies. This systematic review supports the need for more spectroscopy-related investigations relevant to work-related activities and specific to low back musculoskeletal disorders. Rigorous statistical analysis is needed in examining the influence of adipose tissue thickness on haemodynamic responses. Although high reliability of spectroscopy-derived responses was found in the majority of studies, to date there are no investigations that have established their reliability in the low back pain patient population. More importantly, a proper calibration technique to identify the physiological minimum in the paraspinal muscle region is still elusive. Overall, understanding injury mechanisms for low back pain and other associated musculoskeletal disorders with NIR oximeters is still in its infancy. However, with the advent of advanced optical spectroscopy systems in the last decade, the potential for innovative use of NIR oximeters in low back musculoskeletal health-related research is promising.

A means for predicting low-back musculo-skeletal disorders from jolting and jarring of heavy equipment operators

This article presents a step-by-step procedure for predicting the occurrence (or non-occurrence) of lumbar spinal disorders in workers subjected to long-term, whole-body vibration exposure. The procedure consists of relatively simple steps including the use of a biodynamic computer model together with an International Organization for Standardization (ISO) standard. The underlying analysis is based upon Kane's equations and the resulting worker model is validated with experimental data provided by the National Institute for Occupational Safety and Health (NIOSH), Biodynamics Laboratory, University of Vermont, and with published data.

A comparative study of load sharing among back and leg muscles during squat and half-kneeling lifts

This paper presents the results of a comparative study of load sharing among back and leg muscles during squat and half-kneeling lifts. 19 young and healthy subjects with no history of low back pain or other musculoskeletal disorders participated in the study. Muscle activity was measured using electromyography (EMG) technique. Surface EMG electrodes were placed bilaterally at the erector spinae, quadriceps and hamstring muscles. Muscle activities were determined at different force levels representing 40, 60 and 80 percent of maximal voluntary contraction (MVC). The results showed increase in normalised mean RMS (root mean squared) values of EMG of for all the muscles with increasing force levels in both squat and half kneeling lifts. Contralateral and ipsilateral ratio parameters were used to determine the degree of load sharing among the muscles in both lifting postures. Statistical analysis of the mean RMS values and the contralateral and ipsilateral ratio parameters revealed no significant differences between squat and half kneeling lifts. The paper discusses the implications of the results for preventing injuries during manual handling and provides suggestions for future research.

Work characteristics, musculoskeletal disorders, and the mediating role of psychological strain: A study of call center employees.

The demands of the modern office are thought to contribute to the development of musculoskeletal disorders. For upper body and lower back disorders, these effects are hypothesized to be mediated by psychological strain. A study of 936 employees from 22 call centers supports this hypothesis. Using logistic regression and structural equation modeling, the authors found that the relationship of workload to upper body and lower back musculoskeletal disorders was largely accounted for by job-related strain. This mediating effect was less evident for arm disorders. Contrary to expectation, job autonomy had neither a direct nor a moderating effect on any musculoskeletal disorder.

Proceedings: 1St Fimm Scientific Committee Conference. Reliability and Efficacy studies in Low-Back Pain and other Musculoskeletal Disorders. 30TH of January 2003, Odense, Denmark

Proceedings: 1St Fimm Scientific Committee Conference. Reliability and Efficacy studies in Low-Back Pain and other Musculoskeletal Disorders. 30TH of January 2003, Odense, Denmark

Effectiveness of Early Physical Therapy in Low Back Musculoskeletal Disorders

Effectiveness of Early Physical Therapy in Low Back Musculoskeletal Disorders