Costs by industry and diagnosis among musculoskeletal claims in a state workers compensation system: 1999-2004

Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements

BACKGROUND

Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements.

OBJECTIVE

This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height.

METHODS

Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation.

RESULTS

The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P <  0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P <  0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P <  0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P <  0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P <  0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P <  0.0001, respectively).

CONCLUSION

Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

The ACGIH TLV for lifting: Estimated TLVs for torso asymmetry beyond 30 degrees

BACKGROUND

The American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) for Lifting is a manual material handling (MMH) assessment method to identify weight limits that nearly all workers may be exposed to without developing work-related low back disorders (LBD). However, this assessment method only applies to lifting with the torso within 30° asymmetry of the sagittal plane.

OBJECTIVE

Estimate TLV weight limits while lifting with torso asymmetry greater than 30° beyond the sagittal plane.

METHODS

Lifting tasks were performed from various horizontal and vertical locations, at torso asymmetry angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°, using ACGIH identified TLVs. Validated MMH assessment methods (NIOSH Lifting Equation, Ohio State University LBD Risk Model) were utilized to estimate TLVs at torso asymmetries greater than 30°.

RESULTS

The current ACGIH TLVs resulted in low- to moderate-risk risk levels for torso asymmetries from 0° to 30°, and the risk incrementally increased as torso asymmetry increased to 90°. With the intention to keep the risk levels to that found at 30° torso asymmetry, lower TLV weight limits in the vertical and horizontal zones investigated were estimated for torso asymmetries from 45° to 90°. The resulting adjusted TLVs were consistent with weight limits identified for similar lifting conditions from other assessment methods that account for torso asymmetry.

CONCLUSIONS

This research found current ACGIH-defined TLVs possess less than high-risk for LBD, and provided guidance to practitioners for reduced TLVs when torso asymmetry is greater than 30° from the sagittal plane.

Prevalence status and associated factors of wrist postural injury in the Chinese occupational population

Objective

This study investigated the prevalence of wrist injuries in 15 industries and different types of work in China. Study on the associated factors of wrist injuries provides a scientific basis for prevention and treatment of wrist diseases in occupational workers.

Methods

A cross-sectional study of musculoskeletal symptoms of related practitioners in 15 industries, including automobile manufacturing, was conducted to retrieve worker demographic information, working wrist posture, and pain conditions. Multivariable binary logistic regression analyses were performed to identify factors associated with work-related musculoskeletal disorders (WMSDs).

Results

The prevalence of wrist injuries among the study population was 13.2%. Toy manufacturing, animal husbandry, automobile manufacturing, shoe manufacturing, and biopharmaceutical manufacturing had the highest wrist injury rates at 29.1, 19.1, 14.9, 14.9, and 14.0%, respectively. Among the types of jobs, enamel workers (63.0%), butchers (43.6%), combers (32.5%), welders (31.3%), and scaffolders (26.5%) had the highest prevalence rates. Based on the final multivariate logistic regression analysis: female [odds ratios (OR) = 1.24; 95% confidence interval (CI), 1.15-1.35], 6-10 years of service (OR = 1.11; 95% CI, 1.03-1.18), >10 years of service (OR = 1.15; 95% CI, 1.06-1.25), frequent upward and downward flexion in wrist posture at work (OR = 1.81; 95% CI, 1.84-2.11), and frequent wrist placement on the edge of angular objects increased the OR of injury (OR = 1.52; 95% CI, 1.44-1.61). Need to squeeze objects tightly while working (OR = 1.72; 95% CI, 1.57-1.89), prolonged wrist flexion (OR = 1.86; 95% CI, 1.75-1.97), and work hand position above the shoulder for prolonged periods (OR = 1.11; 95% CI, 1.04-1.19) also suggested the relationship between these factors and the higher prevalence of wrist injury in the workers. The associated factor was physical activity (OR = 0.86; 95% CI, 0.80-0.94).

Conclusion

This study suggested the relationship between these factors and the higher prevalence of wrist injury in the toy manufacturing, animal husbandry, automobile manufacturing, and shoe-making industries, enamel workers, butchers, and combers. And are work types that require special attention. Females, working age, physical activity, and abnormal posture of the wrist were factors significantly associated with WMSDs.

Workers' compensation reported injuries among distillery industry workers, 2010-2019

BACKGROUND

The objective of this study was to identify the most frequent type, nature, and cause of work-related injuries among distillery workers and the contributing factors for these events to target interventions to reduce injuries.

METHODS

Workers' compensation first reports of injury (FROI) from the years 2010 through 2019 were obtained. Variables were created for "occupational category" and "cause of injury" for evaluation of the injurious events. The ratchet circular scan test was used to assess seasonal variation in injury, and kernel density estimation to assess rates of injury by calendar year.

RESULTS

A total of 974 FROIs were recorded over these 10 years; 908 of the injuries resulted in lost time, 65 resulted in no lost time, and 1 resulted in a fatality. The most common injuries reported were strains or tears, lacerations, and contusions (33.4%, 14.7%, and 13.5%, respectively). The most frequent anatomical sites of injury were the shoulders, fingers, and low back area (11.8%, 11.4%, and 8.9%, respectively). Barreling operation activities experienced the greatest frequency of work-related injury at 28.5% of all FROIs. A seasonal peak of injuries was observed during May and June.

CONCLUSIONS

Implementing ergonomic and safety solutions for transportation and work tasks associated with barreling operations may significantly reduce the rate of work-related injuries in distillery workers. Injury prevention interventions should particularly target strain or tear injuries caused by repetitive motion or bodily reaction and overexertion. Contact with objects or machinery accounted for one-third of distillery industry FROIs.

A workplace wellness program at an academic health center influences employee health, satisfaction, productivity and the rate of workplace injury

PURPOSE

Workplace wellness (WP) programs are an employer strategy to improve employee health and satisfaction. Their impact on productivity and benefit expense remains unclear. This study examines the association of a voluntary WP at an academic health center with both employee metrics and employer costs.

METHODS

We retrospectively reviewed prospectively collected data from January 2016 to April 2018 for employees who voluntarily underwent screening for a WP at an academic medical center. We used their demographic, social, work, and clinical data to address the central research question. The primary outcomes included wellness measures from the Patient-Reported Outcomes Measurement Information System (PROMIS), secondary wellness outcomes such as body mass index, job-related outcomes such as job satisfaction, and workers' compensation metrics such as the claim amount. The key independent variables were whether an observation was from before or after the WP. For workers' compensation metrics, additional key independent variables were intervention/control group, and an interaction between the before/after and intervention/control variables. We conducted univariate and bivariate/unadjusted analyses, and estimated multivariable linear, logistic, and gamma regression models that also controlled for confounders.

RESULTS

The study included 370 employees. Participation in the program was associated with significant improvements in the PROMIS pain interference, fatigue and sleep quality domains. Hip circumference diminished, and functional movement outcomes were improved. Job satisfaction improved by 4.4 percentage points (95% Confidence Interval [CI]: 0.3-8.5, p = 0.04) and self-reported productivity by 14.5 percentage points (95% Confidence Interval [CI]: 9.5-19.5, p < 0.001). The likelihood of a new compensation claim during the 12-month follow-up period fell by 10.1% (95% Confidence Interval [CI]: - 15.5 to - 4.7, p < 0.001). However, the value of a new claim was unchanged.

CONCLUSION

Employees who completed a WP at an academic medical center demonstrated improvements in several recognized patient-reported outcome measures, in job satisfaction and self-reported productivity, a decrease in hip circumference, an improvement in functional motion and a decreased rate of compensable injury.

Workers' compensation costs for healthcare caregivers: Home healthcare, long-term care, and hospital nurses and nursing aides

BACKGROUND

Healthcare workers (nurses and nursing aides) often have different exposures and injury risk factors depending on their occupational subsector and location (hospital, long-term care, or home health care).

METHODS

A total of 5234 compensation claims for nurses and nursing aides who suffered injuries to their lower back, knee, and/or shoulder over a 5-year period were obtained from the Ohio Bureau of Workers' Compensation and analyzed. Injury causation data was also collected for each claim. The outcome variables included indemnity costs, medical costs, total costs, and the number of lost work days. The highest prescribed morphine equivalent dose for opioid medications was also calculated for each claim.

RESULTS

Home healthcare nurses and nursing aides had the highest average total costs per claim. Hospital nurses and nursing aides had the highest total claim costs, of $5 million/year. Shoulder injuries for home healthcare nursing aides (HHNAs) had the highest average total claim costs ($20,600/injury) for all occupation, setting, and body area combinations. Opioids were most frequently prescribed for home healthcare nurses (HHNs) and nursing aides (18.9% and 17.7% having been prescribed opioids, respectively). Overexertion was the most common cause for HHN and nursing aide claims.

CONCLUSIONS

With the rapidly expanding workforce in the home healthcare sector, there is a potential health crisis from the continued expansion of home healthcare worker injuries and their associated costs. In addition, the potential for opioid drug usage places these workers at risk for future dependence, overdose, and prolonged disability. Future research is needed to investigate the specific and ideally reversible causes of injury in claims categorized as caused by overexertion.

Workers' Societal Costs After Knee and Shoulder Injuries and Diagnosis with In-Office Arthroscopy or Delayed MRI: A Cost-Minimization Analysis

The goal of this study was to evaluate the societal costs of using in-office diagnostic arthroscopy (IDA) compared with magnetic resonance imaging (MRI) for the diagnosis of intra-articular knee and shoulder pathology in employed patients receiving Workers' Compensation or disability coverage. The prevalence is estimated at 260,000 total cases per year.

METHODS

A cost-minimization analysis of IDA compared with MRI was conducted. Direct costs (in 2018 U.S. dollars) were calculated from private reimbursement amounts and Medicare. Indirect costs were estimated from a societal perspective including effects of delayed surgical procedures on the ability to work, lost income, Workers' Compensation or disability coverage, and absenteeism. Four regions were selected: Boston, Massachusetts; Detroit, Michigan; Denver, Colorado; and San Bernadino, California. Sensitivity analyses were performed using TreeAge Pro 2019 software. The base assumption was that it would take approximately 4 weeks for a diagnosis with MRI and 0 weeks for a diagnosis with IDA.

RESULTS

Direct costs to determine a knee diagnosis with IDA were $556 less expensive (California) to $470 more expensive (Massachusetts) than MRI. Assuming a 4-week wait, societal costs (indirect and direct) for knee diagnosis were anywhere from $7,852 (Denver) to $11,227 (Boston) less using IDA. Direct costs were similar for shoulder pathology. In order for MRI to be the less costly option, the MRI and the follow-up visit to the physician would need to occur directly after consultation. Under Medicare, direct costs were similar for both the knee and shoulder when comparing IDA and MRI. Including indirect costs resulted in IDA being the less costly option.

CONCLUSIONS

The use of IDA instead of MRI for the diagnosis of knee and shoulder pathology reduced costs. The potential savings to society were approximately $7,852 to $11,227 per operative patient and were dependent on scheduling and follow-up using MRI and on Workers' Compensation.

LEVEL OF EVIDENCE

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

Trunk Flexion Monitoring among Warehouse Workers Using a Single Inertial Sensor and the Influence of Different Sampling Durations

Trunk flexion represents a risk factor for the onset of low-back disorders, yet limited quantitative data exist regarding flexion exposures in actual working conditions. In this study, we evaluated the potential of using a single inertial measurement unit (IMU) to classify trunk flexion, in terms of amplitude, frequency, and duration, and assessed the influence of alternative time durations on exposure results. Twelve warehouse workers were monitored during two hours of an actual shift while wearing a single IMU on their low back. Trunk flexion data were reduced using exposure variation analysis integrated with recommended exposure thresholds. Workers spent 5.1% of their working time with trunk flexion of 30-60° and 2.3% with flexion of 60-90°. Depending on the level of acceptable error, relatively shorter monitoring periods (up to 50 min) might be sufficient to characterize trunk flexion exposures. Future work is needed, however, to determine if these results generalize to other postural exposures and tasks.

Effects of a Participatory Ergonomics Intervention With Wearable Technical Measurements of Physical Workload in the Construction Industry: Cluster Randomized Controlled Trial

Background

Construction work frequently involves heavy physical work, and a reduction of the physical workload should have high priority. Technological development has made it possible to obtain field measurements with surface electromyography (sEMG), kinematics measured with inertial measurement units (IMUs), and video recordings. However, no studies have used these methods simultaneously to detect situations with excessive physical workload (events) during a working day. Thus, knowledge about these specific events may combat work-related risk factors. Participatory ergonomics (PE) has shown promising results, but whether it can be used as a tool to reduce the physical workload during construction work remains unknown.

Objective

This cluster randomized controlled trial investigated whether a PE intervention with technical measurements consisting of IMUs, sEMG, heart rate monitoring, and video recordings of physical workload could reduce the number of events with excessive physical workload during a working day. Furthermore, other outcomes were obtained from questionnaires.

Methods

A total of 80 male full-time construction workers (aged 19 to 67 years) were randomized at the cluster level (gang) to a PE intervention consisting of 3 workshops (7 gangs and 32 workers) or to a control group (8 gangs and 48 workers). The physical workload was recorded by technical measurements, that is, IMUs, sEMG, heart rate monitoring, and video recordings during a full working day at baseline and 3 and 6 months’ follow-up. On the basis of the technical measurements, a custom-made computer program detected the situations (events) where the construction workers were exposed to excessive physical workload and used in the intervention. Differences in the number of events from baseline to follow-up between intervention and control were evaluated using linear mixed models (intention-to-treat), with individual nested in cluster as a random factor. Furthermore, questionnaires were filled out on test days.

Results

The results of the primary outcome showed no change in the number of events with excessive physical workload. However, compared with the control group, the other outcomes showed decreased general fatigue after a typical working day (P=.001) and increased influence on own work (P=.04).

Conclusions

This PE intervention with technical measurements did not reduce the number of events with excessive physical workload during construction work. However, the intervention led to decreased general fatigue and increased influence on own work.

Trial Registration

ClinicalTrials.gov NCT02498197; https://clinicaltrials.gov/ct2/show/NCT02498197 (Archived by WebCite at http://www.webcitation.org/74SZ3DIWS)

Measurement properties of instruments assessing permanent functional impairment of the spine: a systematic review protocol

INTRODUCTION

Permanent functional impairment (PFI) of the spine is a rating system used by compensation authorities, such as workers compensation boards, to establish an appropriate level of financial compensation for persistent loss of function. Determination of PFI of the spine is commonly based on the assessment of spinal movement combined with other measures of physical and functional impairments; however, the reliability and validity of the measurement instruments used for these evaluations have yet to be established. The aim of this study is to systematically review and synthesise the literature concerning measurement properties of the various and different instruments used for assessing PFI of the spine.

METHODS

Three conceptual groups of terms (1) PFI, (2) spinal disorder and (3) measurement properties will be combined to search Medline, EMBASE, CINAHL, Web of Science, Scopus, PEDro, OTSeeker and Health and Safety Science Abstracts. We will examine peer-reviewed, full-text articles over the full available date range. Two reviewers will independently screen citations (title, abstract and full text) and perform data extraction. Included studies will be appraised as to their methodological quality using the COnsensus-based Standards for the selection of health Measurement INstruments criteria. Findings will be summarised and presented descriptively, with meta-analysis pursued as appropriate.

ETHICS AND DISSEMINATION

This review will summarise the current level of evidence of measurement properties of instruments used for assessing PFI of the spine. Findings of this review may be applicable to clinicians, policy-makers, workers' compensation boards, other insurers and health and safety organisations. The findings will likely provide a foundation and direction for future research priorities for assessing spinal PFI.

PROSPERO REGISTRATION NUMBER

CRD42017060390.

Vibration and Ergonomic Exposures Associated With Musculoskeletal Disorders of the Shoulder and Neck

Background

According to the US Bureau of Labor Statistics, musculoskeletal disorders (MSDs) accounted for 32% of all nonfatal injury and illness cases in 2014 among full-time workers. Our objective was to review and summarize the evidence linking occupational exposures to vibration and awkward posture with MSDs of the shoulder and neck.

Methods

A literature search was conducted using the terms musculoskeletal disorders, vibration, and awkward posture. All types of observational epidemiologic studies, with the exception of case reports, published during 1998–2015 were included. Databases searched were MEDLINE (Ovid), Embase (Ovid), Scopus, Ergonomic Abstracts, NIOSHTIC-2, and Health and Safety Science Abstracts.

Results

Occupational exposures to whole-body or hand–arm vibration were significantly associated with or resulted in MSDs of the shoulder and neck. Awkward postures while working were also associated with MSDs in these locations. These findings were consistent across study designs, populations, and countries.

Conclusion

Occupational exposure to vibration and awkward posture are associated with shoulder and neck MSDs. Longitudinal studies are required to elucidate the mechanisms responsible for these associations, and intervention studies are warranted.

Postoffer Pre-Placement Screening for Carpal Tunnel Syndrome in Newly Hired Manufacturing Workers

OBJECTIVE

We determined the predictive validity of a postoffer pre-placement (POPP) screen using nerve conduction velocity studies (NCV) to identify future cases of carpal tunnel syndrome (CTS).

METHODS

A cohort of 1648 newly hired manufacturing production workers underwent baseline NCS, and were followed for 5 years.

RESULTS

There was no association between abnormal POPP NCV results and incident CTS. Varying NCV diagnostic cut-offs did not improve predictive validity. Workers in jobs with high hand/wrist exposure showed greater risk of CTS than those in low exposed jobs (relative risk 2.82; 95% confidence interval 1.52 to 5.22).

CONCLUSIONS

POPP screening seems ineffective as a preventive strategy for CTS.

Prevalence and its risk factors for low back pain among operation and maintenance personnel in wind farms

Background

With the increasingly severe energy shortage and climate change problems, developing wind power has become a key energy development strategy and an inevitable choice to protect the ecological environment worldwide. The purpose of this study was to investigate the prevalence of low back pain (LBP) and analyze its risk factors among operation and maintenance personnel in wind farms (OMPWF).

Methods

A cross-sectional survey of 151 OMPWF was performed, and a comprehensive questionnaire, which was modified and combined from Nordic Musculoskeletal Questionnaires (NMQ), Washington State Ergonomics Tool (WSET) and Syndrome Checklist-90(SCL-90) was used to assess the prevalence and risk factors of LBP among OMPWF.

Results

The prevalence of LBP was 88.74 % (134/151) among OMPWF. The multivariable model highlighted four related factors: backrest, somatization, squatting and lifting objects weighing more than 10 lb more than twice per minute.

Conclusions

The prevalence of LBP among OMPWF appears to be high and highlights a major occupational health concern.

Prevalence of Metabolic Syndrome and Its Components among Japanese Workers by Clustered Business Category

The present study was a cross-sectional study conducted to reveal the prevalence of metabolic syndrome and its components and describe the features of such prevalence among Japanese workers by clustered business category using big data. The data of approximately 120,000 workers were obtained from a national representative insurance organization, and the study analyzed the health checkup and questionnaire results according to the field of business of each subject. Abnormalities found during the checkups such as excessive waist circumference, hypertension or glucose intolerance, and metabolic syndrome, were recorded. All subjects were classified by business field into 18 categories based on The North American Industry Classification System. Based on the criteria of the Japanese Committee for the Diagnostic Criteria of Metabolic Syndrome, the standardized prevalence ratio (SPR) of metabolic syndrome and its components by business category was calculated, and the 95% confidence interval of the SPR was computed. Hierarchical cluster analysis was then performed based on the SPR of metabolic syndrome components, and the 18 business categories were classified into three clusters for both males and females. The following business categories were at significantly high risk of metabolic syndrome: among males, Construction, Transportation, Professional Services, and Cooperative Association; and among females, Health Care and Cooperative Association. The results of the cluster analysis indicated one cluster for each gender with a higher prevalence of metabolic syndrome components; among males, a cluster consisting of Manufacturing, Transportation, Finance, and Cooperative Association, and among females, a cluster consisting of Mining, Transportation, Finance, Accommodation, and Cooperative Association. These findings reveal that, when providing health guidance and support regarding metabolic syndrome, consideration must be given to its components and the variety of its prevalence rates by business category and gender.

The effectiveness of post-offer pre-placement nerve conduction screening for carpal tunnel syndrome

OBJECTIVE

We evaluated post-offer pre-placement (POPP) nerve conduction studies (NCS) for carpal tunnel syndrome (CTS), testing diagnostic yield and cost-effectiveness.

METHODS

A total of 1027 newly hired workers underwent baseline NCS and were followed for an average of 3.7 years for diagnosed CTS. Measures of diagnostic yield included sensitivity, specificity, and positive predictive value (PPV). Cost-effectiveness of POPP screening was evaluated using a range of inputs.

RESULTS

Abnormal NCS was strongly associated with future CTS with univariate hazard ratios ranging from 2.95 to 11.25, depending on test parameters used. Nevertheless, PPV was poor, 6.4% to 18.5%. Cost-effectiveness of POPP varied with CTS case costs, screening costs, and NCS thresholds.

CONCLUSIONS

Although abnormal NCS at hire increases risk of future CTS, the PPV is low, and POPP screening is not cost-effective to employers in most scenarios tested.

Immune responses to low back pain risk factors

$\underline{Objective}$: Investigate effects of interactions between biomechanical, psychosocial and individual risk factors on the body's immune inflammatory responses. $\underline{Background}$: Current theories for low back pain causation do not fully account for the body's response to tissue loading and tissue trauma. $\underline{Methods}$: Two groups possessing a preference for the sensor or intuitor personality trait performed repetitive lifting combined with high or low mental workload on separate occasions. Spinal loading was assessed using an EMG-assisted subject-specific biomechanical model and immune markers were collected before and after exposure. $\underline{Results}$: Mental workload was associated with a small decrease in AP shear. Both conditions were characterized by a regulated time-dependent immune response making use of markers of inflammation, tissue trauma and muscle damage. Intuitors' creatine kinase levels were increased following low mental workload compared to that observed in Sensors with the opposite trend occurring for high mental workload. $\underline{Conclusions}$: A temporally regulated immune response to lifting combined with mental workload exists. This response is influenced by personality and mental workload.

Work-related knee injuries treated in US emergency departments

OBJECTIVE

To characterize work-related knee injuries treated in US emergency departments (EDs).

METHODS

We characterized work-related knee injuries treated in EDs in 2007 and examined trends from 1998 to 2007 by using the National Electronic Injury Surveillance System-occupational supplement.

RESULTS

In 2007, 184,300 (± 54,000; 95% confidence interval) occupational knee injuries were treated in US EDs, accounting for 5% of the 3.4 (± 0.9) million ED-treated occupational injuries. The ED-treated knee injury rate was 13 (± 4) injuries per 10,000 full-time equivalent workers. Younger workers and older female workers had high rates. Strains/sprains and contusions/abrasions were common-frequently resulting from falls and bodily reaction/overexertion events. Knee injury rates declined from 1998 through 2007.

CONCLUSIONS

Knee injury prevention should emphasize reducing falls and bodily reaction/overexertion events, particularly among all youth and older women.

Biomechanical, psychosocial and individual risk factors predicting low back functional impairment among furniture distribution employees

BACKGROUND

Biomechanical, psychosocial and individual risk factors for low back disorder have been studied extensively however few researchers have examined all three risk factors. The objective of this was to develop a low back disorder risk model in furniture distribution workers using biomechanical, psychosocial and individual risk factors.

METHODS

This was a prospective study with a six month follow-up time. There were 454 subjects at 9 furniture distribution facilities enrolled in the study. Biomechanical exposure was evaluated using the American Conference of Governmental Industrial Hygienists (2001) lifting threshold limit values for low back injury risk. Psychosocial and individual risk factors were evaluated via questionnaires. Low back health functional status was measured using the lumbar motion monitor. Low back disorder cases were defined as a loss of low back functional performance of -0.14 or more.

FINDINGS

There were 92 cases of meaningful loss in low back functional performance and 185 non cases. A multivariate logistic regression model included baseline functional performance probability, facility, perceived workload, intermediated reach distance number of exertions above threshold limit values, job tenure manual material handling, and age combined to provide a model sensitivity of 68.5% and specificity of 71.9%.

INTERPRETATION

The results of this study indicate which biomechanical, individual and psychosocial risk factors are important as well as how much of each risk factor is too much resulting in increased risk of low back disorder among furniture distribution workers.

Burden of work-related knee disorders in Washington State, 1999 to 2007

OBJECTIVE

To describe the burden of knee work-related musculoskeletal disorders (WMSDs).

METHODS

Knee WMSDs were identified using Washington State Fund workers' compensation data from 1999 to 2007 and analyzed by cost, industry, occupation, and claims incidence rates.

RESULTS

Knee WMSDs accounted for 7% of WMSD claims and 10% of WMSD costs. The rate of decline in claims incidence rates for knee WMSDs was similar to the rate of decline for all other WMSDs. Industries at highest risk for knee WMSDs included construction and building contractors. Occupations of concern included carpenters and truck drivers in men and nursing aides and housekeepers in women.

CONCLUSIONS

Between 1999 and 2007, Washington State Fund knee WMSDs were widespread and associated with a large cost. Identification of specific occupational knee WMSD risk factors in high-risk industries is needed to guide prevention efforts.