Evidence-based practice for acute low back pain in primary care: Patient outcomes and cost of care

Provider adherence with clinical practice guidelines (CPGs) for acute low back pain (LBP) and its impact on clinical outcomes and cost are controversial. A panel and cross-sectional design was used to determine the rate of provider adherence to the Department of Defense/Veteran's Administration CPG for Acute LBP which included ergonomic and psychosocial intervention. The relationship among adherent care, patient satisfaction, general health, functional outcome, and cost was examined. Direct health services and patient survey data 1 year before and 3 years following guideline implementation were analyzed. The sample consisted of 15,789 LBP cases (CPG) and 14,409 upper extremity cases used as controls (no CPG). Ten to 40% of LBP cases received CPG-adherent care across the 4 years. No differences were found between LBP and upper extremity diagnoses groups in the rates of change in the four outcomes over years. Multivariable regression analyses controlling for demographic variables and perceived health indicated that CPG adherence was related to better functional outcomes, Odds ratio (OR)=1.45 [95% CI=1.31-1.60] and lower healthcare costs (beta=-230.15, p<0.001). Cases receiving more adherent care also reported higher levels of patient satisfaction (beta=0.09, p<0.05) and general health, OR=1.44 [95% CI=1.29-1.60]. Higher levels of adherent care which included efforts to address both ergonomic and psychosocial factors in the course of acute back pain were related to better clinical outcomes and lower costs.

Innovative applications of epidemiology, evidenced based interventions and economic analyses of office related upper extremity disorders

In September 2005 a small working conference was held to generate potential next steps in the generation of innovative approaches to work related upper extremity symptoms and disorders among those working in office environments. This special section of the Journal includes papers written by the presenters and their collaborators. These papers provide "state of the art" summaries of research in the areas of ergonomics, biobehavioral factors and interventions, economics and integrative interventions at the workplace. Invited speakers and participants from various stakeholder groups spent a second day discussing the implications of the research presented on day one for improving the understanding and management of these disorders. Practical considerations for generating new approaches and their implementation were also discussed.

How Do Job Stress and Ergonomic Factors Impact Clinic Visits in Acute Low Back Pain? A Prospective Study

OBJECTIVE

We sought to identify whether ergonomic factors, job stress, health behavior, and emotional distress are prospectively related to return visits for acute back pain.

METHODS

A total of 368 U.S. Army soldiers completed a baseline survey of health and work factors at their first visit for back pain. Multivariable regression and structural equation modeling were used to describe the relationships among ergonomic exposure, job stress, smoking, and emotional distress and their ability to predict repeat clinic visits.

RESULTS

The path analysis indicated that higher levels of ergonomic exposures were directly related to increased job stress (beta = 0.29). Higher levels of job stress were directly related to higher levels of general distress (beta = -35). General distress (beta = -0.70) and smoking (beta = 0.67) were directly linked to clinic visits.

CONCLUSIONS

Efforts to directly impact emotional distress or indirectly reduce distress by intervening at the levels of ergonomic risks and psychosocial workplace stress should prove useful in the management of acute low back pain.

Recommendations for the U.S. National Occupational Research Agenda: research on cancer survivorship and musculoskeletal disorders and work disability

Occupational health and safety focuses on health problems in the working population. Disability is a significant problem that results in both functional and financial consequences to the worker and society. A problem becoming more evident in the workplace is cancer. As technological advances improve in the early recognition and treatment of cancer and our working population ages, the number of survivors who face challenges returning to work and maximizing productivity while at work will increase. Research is needed to identify the barriers that affect cancer survivors at work and evaluate innovative interventions to assist these workers in both their return to work and long term success at work. Musculoskeletal disorders continue to be a leading cause of work disability in the US. Limited function, pain, lost work time, emotional distress and financial burden are many of the problems associated with musculoskeletal symptoms and disorders. We presented these areas of research needs for the coming decade at the National Occupational Research Agenda (NORA) town hall meeting. The following is our testimony given on December 5, 2005 in College Park, Maryland.

Development of a short form of the Workstyle measure

BACKGROUND

'Workstyle', or how a worker behaviourally, cognitively and physiologically responds to increased or stressful work demands, has been proposed to help explain the link between ergonomic and psychosocial factors in work-related upper limb disorder symptoms and disorders (WRULD).

AIM

To describe the psychometric properties of a shortened version of the original Workstyle measure.

METHODS

Factor analyses of the Workstyle measure items were conducted to reduce the number of total items. Each of the subscales was then further reduced by randomly selecting half of the items within each subscale. Additionally, two subscales from the original survey (Pain/Tension and Numbness/Tingling) were eliminated because they were not used to calculate the original workstyle total score in order to reduce the influence of current symptoms on an individual's total score.

RESULTS

The Workstyle Short Form was reduced to 32 items. Cronbach's alpha was 0.89 and the test-retest reliability was r = 0.88, P < 0.01, for the total score. The short form score was significantly correlated with the full workstyle total score, r = 0.98, P < 0.01. Higher total workstyle scores were significantly associated with pain, functional limitations and adverse mental and physical health.

CONCLUSION

The Workstyle Short Form demonstrated acceptable psychometric properties. These findings indicate its potential utility in research on WRULD.

Integrating psychosocial and behavioral interventions to achieve optimal rehabilitation outcomes

INTRODUCTION

Psychosocial factors are important contributors to work disability associated with musculoskeletal conditions. The primary objectives of this paper were 1) to describe different psychosocial interventions that have been developed to prevent prolonged work disability, and 2) to identify future research directions that might enhance the impact of programs targeting psychosocial risk factors for work disability.

METHODS

Selective review of scientific literature on psychosocial and behavioral interventions and work disability.

RESULTS

Most prior interventions focused on psychosocial risk factors that exist primarily within the individual (e.g., pain catastrophizing, beliefs, expectancies). Successful disability prevention will require methods to assess and target psychosocial risk factors "outside" of the individual (e.g., interpersonal conflict in the workplace, job stress, etc.) using cost-effective, multipronged approaches. Research to explore interactions among different domains of psychosocial risk factors in relation to RTW outcomes is needed. Challenges to effective secondary prevention of work disability include developing competencies to enable a range of providers to deliver interventions, standardization of psychosocial interventions, and maximizing adherence to intervention protocols.

CONCLUSION

Effective secondary prevention of work disability will require research to develop cost-effective, multipronged approaches that concurrently target both worker-related and workplace psychosocial risk factors.

An interpreter's interpretation: sign language interpreters' view of musculoskeletal disorders

INTRODUCTION

Sign language interpreters are at increased risk for musculoskeletal disorders associated with work. Previous studies have used survey techniques to identify potential risk factors and approaches to their medical management. Little is known about risk factors and management of symptoms in this group from the perspective of the interpreter. Such qualitative information should help inform future research related to this professional group.

METHOD

One thousand ninety-two sign language interpreters recruited from the Registry of Interpreters for the Deaf completed an open-ended question that was a component of a national prevalence survey. Responses were evaluated using content analysis. Inter and intra rater reliability were high (.88 and .92, respectively).

RESULTS

Risk factors for initiation and/or exacerbation of symptoms included: difficult job, interpreting setting (educational), interpreting style (e.g., posture, self generated force), and emotional and physical stressors. Exercise (e.g., stretching, aerobics) was a common prevention strategy. Conventional medical treatment was used as the first line approach to symptom control. Self-care methods such as exercise, diet and warm up prior to interpreting were also reported. While massage and chiropractic care was used as commonly as in the general population, acupuncture was found to be used more often. Coping strategies that were more active (e.g. exercise, diet, more control over work schedule) were also reported as useful.

CONCLUSIONS

These findings provide a description of factors that interpreters view as important in the development and exacerbation of hand and wrist pain. The results also indicate that interpreters used many self-management approaches. Future research should carefully investigate the utility of such approaches using well-controlled designs. Also, because of its widespread use in this group the evaluation of acupuncture in the management of these symptoms appears warranted. The qualitative approach used in the present study permitted an analysis of the worker perspectives regarding risk and management of these work related symptoms. This information can be used to further inform future research.

Workstyle: development of a measure of response to work in those with upper extremity pain

Workstyle or the behavioral, cognitive, and physiological response that can occur in some individuals to increases in work demands has been proposed to help explain the link between ergonomic and psychosocial factors in the exacerbation of work-related upper extremity symptoms. Currently, there is no measure of this construct, hindering research on its potential link to work related upper extremity problems in the workplace. The present study describes the development and psychometric properties of a measure of workstyle. Questionnaire items reflecting dimensions of workstyle as per the original conceptualization were generated primarily through focus groups with office workers and separate groups held with occupational physicians, physical therapists, occupational health psychologists, and experts in ergonomics, behavioral science, and human factors. Items created through this process were then administered to 282 symptomatic and asymptomatic office workers. Measures of job stress, ergonomic risk, upper extremity symptoms, and functional limitations were also obtained. The workstyle questionnaire was divided into two broad dimensions: Characteristic responses to work and Response to increased work demands. The scale development process as indicated by factor analysis yielded subscales that are theoretically consistent with the workstyle construct. These subscales include: working through pain, social reactivity at work, limited workplace support, deadlines/pressure, self imposed work pace/workload, breaks, mood, pain/tension, autonomic response, and numbness tingling. The internal consistency of these subscales varied from 0.61 to 0.91, n = 282 while the test-retest (3 weeks) reliability for the various subscales ranged from r = 0.68 to 0.89, n = 143. A total workstyle score was computed that excluded the pain/tension and numbness/tingling subscales to avoid circular reasoning in terms of the measure's relationship to outcomes of pain and functional limitations. The total score was stable over time and provided unique variance in relation to traditional measures of job stress. Total workstyle score was significantly associated with higher levels of pain, and greater functional limitations. Dimensions of the workstyle construct were identified. The workstyle measure possesses acceptable psychometric properties in office workers who work with computers. This measure can be used in future studies on the interaction of psychosocial and ergonomic factors in the exacerbation of upper extremity pain and functional limitation.

Self-report measure of low back-related biomechanical exposures: clinical validation

Low back pain and symptoms are major contributors to ambulatory visits, economic burden, and reduced readiness among military personnel and employers in the civilian workplace as well. While a link between low back pain and biomechanical exposures has been established, efficient surveillance methods of such exposures are still needed. Furthermore, the utility of self-report measures for biomechanical exposures has not been examined extensively. The present cross-sectional study analyzed questionnaire data from US Army soldiers (n = 279) working in previously identified occupational specialties that were associated with high risk for low back pain and/or low back pain disability. Demographic characteristics, physical workload, health behaviors, and psychosocial factors were assessed in addition to self-reported workplace biomechanical exposures using the Job Related Physical Demands (JRPDs). Outcomes included self-reported low back pain severity, low back symptoms, functional limitations, and general physical health. The results indicated that the self-report measure of biomechanical exposure had a high degree of internal consistency (Cronbach alpha, 0.95). The JRPD index correlated with low back symptoms, pain intensity, function, and perceived work load using the Borg scale. Regression analyses indicated statistically significant associations between the JRPD and back pain specific pain severity and physical function, but not for general physical health (SF-12) after controlling for age, gender, educational level, job type, and reported exercise and work stress. Specifically, higher JRPD scores (representing greater biomechanical exposure) were associated with higher levels of pain intensity and functional limitations. Higher JRPD scores were found to place an individual at a greater likelihood for being a case with low back pain within the past 12 months (OR = 1.01 per point increase in scale-95%; range 38-152; CI = 1.00-1.02, p < or = 0.05). While future longitudinal studies of the JRPD determining the predictive validity of the measure are needed, the present study provides evidence of the utility of the JRPD for assessing biomechanical exposures associated with low back pain within high-risk jobs. The findings suggest that the JRPD may assist with surveillance efforts and be useful as a process and/or outcome measure in research related to occupational rehabilitation.

Workstyle and Upper-Extremity Symptoms: A Biobehavioral Perspective

OBJECTIVES

Workstyle has been proposed to help explain the link between ergonomic and psychosocial factors in work-related upper-extremity symptoms/disorders. This study investigated ergonomic factors, work demands, job stress, and workstyle on pain and functional limitations in computer users.

METHODS

One hundred sixty-nine participants completed self-report ratings of job stress, ergonomic exposures, and workstyle at baseline. Three months, later ratings of pain and functional limitations were obtained.

RESULTS

Multivariable logistic regression indicated that ergonomic exposure (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.3-5.5), time spent at a computer (OR = 1.9, 95% CI = 0.95-3.6), and higher scores on a workstyle measure (2.4, 95% CI = 1.1-5.3) were independently associated with case status. Path analyses revealed that a model that included ergonomic exposure, work demands, and workstyle predicted pain and functional limitations at 3 months.

CONCLUSIONS

Workstyle contributes to case definition and is predictive of future pain and functional limitations in office workers with upper extremity symptoms.

Cancer survivorship and work

This brief paper emphasizes that much of the knowledge and skills in the area of musculoskeletal disorders and work disability can be brought to bear on understanding and then intervening in the area cancer survivorship and work.

Job stress management and ergonomic intervention for work-related upper extremity symptoms

In practice the secondary prevention of work-related upper extremity (WRUE) symptoms generally targets biomechanical risk factors. Psychosocial risk factors have also been shown to play an important role in the development of WRUE symptom severity and future disability. The addition of a stress management component to biomechanically focused interventions may result in greater improvements in WRUE symptoms and functional limitations than intervening in the biomechanical risk factors alone. Seventy office workers with WRUE symptoms were randomly assigned to an ergonomics intervention group (assessment and modification of work station and stretching exercises) or a combined ergonomic and job stress intervention group (ergonomic intervention plus two 1-h workshops on the identification and management of workplace stress). Baseline, 3- and 12-month follow-up measures of observed ergonomic risks and self-reported ergonomic risks, job stress, pain, symptoms, functional limitation, and general physical and mental health were obtained from all participants. While both groups experienced significant decreases in pain, symptoms, and functional limitation from baseline to three months with improvements continuing to 12 months post baseline, no significant differences between groups were observed for any outcome measures. Findings indicate that the additional two-session job stress management component did not significantly enhance the short- or long-term improvements brought about by the ergonomic intervention alone.

Differentiating sensory and affective-sensory pain descriptions in patients undergoing magnetic resonance imaging for persistent low back pain

The study design is a cross-sectional survey with psychometric analysis. The objective is to determine the validity of a modified version of the Short-Form McGill Pain Questionnaire (SF-MPQ). The SF-MPQ has been widely used to differentiate between reports of sensory and affective pain. The validity of this instrument to reflect independence between these constructs remains unclear. The SF-MPQ, the Roland-Morris Questionnaire (RM) and a measure of current pain intensity were completed by 373 patients undergoing lumbar magnetic resonance imaging (MRI). Four hypothesized factor structures for the SF-MPQ (three 2-factor and one 1-factor solution) were tested using confirmatory factor analysis. A modified 2-factor solution (MSF-MPQ) containing 3 items labeled sensory and 5 items labeled affective-sensory had the best degree of fit. Correlations between factors were substantially lower for the modified 2-factor solution (0.48) than for previously described 2-factor solutions (0.88 and 0.92) indicating a higher degree of independence between these factors. Correlations with measures of pain intensity and the RM were significant, but slightly lower, for the subscales of the modified 2-factor solution (0.26-0.40) than for the subscales of the previously described 2-factor solutions (0.34-0.45). The MSF-MPQ can be used as a brief tool to differentiate the language used to describe pain in patients who are undergoing lumbar MRI. The evidence indicates that this clinical tool can be used to categorize how these patients describe their pain and potentially may be very valuable in determining the optimal course of treatment.

Generating workplace accommodations: lessons learned from the integrated case management study

Modified duty and other accommodations by employers have been shown to be helpful in managing workplace disability associated with injuries and illnesses. Benefits of accommodation have been attributed to both reduced physical and psychosocial exposures. Although many employers have adopted proactive return to work policies that emphasize temporary work modifications, standardized methods for specifying appropriate accommodations have been elusive. On the basis of the experiences and results of a randomized controlled study of case management services for work-related upper extremity disorders, we describe issues pertaining to the application of self-report measures of function and exposure assessment for generating accommodations. Challenges of this approach are 1) including specific work tasks on measures of physical function; 2) improving concordance between ergonomic exposure categories and methods of accommodation; and 3) providing a structured process for negotiating employee and employer preferences. To improve the effectiveness and efficiency of accommodation efforts, new tools for assessing function and ergonomic exposures in the workplace should be developed to specify accommodations more directly.

From confounders to suspected risk factors: psychosocial factors and work-related upper extremity disorders

Psychosocial variables have recently been more prominent among epidemiologic risk factors for work-related upper extremity disorders (WRUEDs), but bio-behavioral mechanisms underlying these associations have been elusive. One reason is that the psychosocial domain has included many broad and disparate variables (e.g. mood, coping skills, job control, job satisfaction, job stress, social support), and this lack of specificity in the conceptualization of psychosocial factors has produced limited hypothesis testing opportunities. Therefore, recent research efforts have focused on identifying and conceptualizing specific psychosocial factors that might more clearly delineate plausible bio-behavioral mechanisms linking psychosocial factors to WRUEDs. One such factor is workstyle, a strategy that workers may employ for completing, responding to, or coping with job demands that might affect musculoskeletal health. Preliminary studies have provided support for measurable differences in workstyle among individual workers and an association with upper extremity pain and discomfort. An initial self-report measure of workstyle has been pilot tested among office workers and shown acceptable reliability and validity. Future studies are needed to study this construct among other working populations and to determine its relationship with other clinical endpoints. Nevertheless, early findings suggest workstyle may be a potential focus of WRUED prevention efforts.

Identifying work organization targets for a work-related musculoskeletal symptom prevention program

While research linking work organization factors to work-related musculoskeletal disorders has been increasing, there is still a need to delineate specific dimensions to be targeted by intervention programs. The present cross-sectional investigation identified work organization risk factors for low back (LB) and upper extremity (UE) symptoms and determined the magnitudes of such associations. Questionnaires containing items on ergonomic, individual psychosocial, and occupational psychosocial factors were administered to a sample of workers (n = 248 U.S. Marines) in previously identified high-risk job categories for musculoskeletal disorders. Study participants were categorized into groups of either having LB symptoms only, UE symptoms only, concurrent LB and UE symptoms, or being asymptomatic on the basis of self-report. Additionally, measures of pain intensity, physical function, and mental health were obtained. Linear regression analyses adjusting for demographics, ergonomic factors, and individual psychosocial factors indicated that decision authority and experienced responsibility for work were significant correlates for pain intensity during the week. Logistic regression analyses indicated that ergonomic stressors were a risk factor for all symptomatic groups (OR = 1.02 per point increase; 95% CI: 1.0-1.1). Time pressure (OR = 1.2 per point increase; 95% CI: 1.0-1.4) was also a significant risk factor for all symptomatic groups, while cognitive processing placed workers at higher risks for concurrent LB and UE symptoms (OR = 1.2; 95% CI: 1.0-1.4). Interpersonal demands placed individuals at a lower risk for LB symptoms (OR = 0.8; 95% CI: 0.5-1.0). Findings highlight the importance of intervention approaches that address time pressure, cognitive processing factors, and interpersonal demands at work. In light of past biobehavioral studies, these results also suggest that job redesign and interventions that address a worker's workstyle when faced with increased work demands may help reduce the likelihood of musculoskeletal symptoms and/or their intensity.

National trends in nonoperative care for nonspecific back pain

BACKGROUND CONTEXT

Few empirical data are available that document changes in population-based rates for the evaluation and treatment of nonspecific back pain.

PURPOSE

To determine the extent of change in the pattern of outpatient evaluation and treatment of nonspecific low back pain in the United States between 1987 and 1997.

STUDY DESIGN AND SETTING

The 1987 National Medical Expenditure Survey and the 1997 Medical Expenditure Panel Survey, two nationally representative surveys with similar sampling methods and questions, were used.

PATIENT SAMPLE

Noninstitutionalized adults in the United States.

OUTCOME MEASURES

Changes in rates of any health service for nonspecific back pain and occurrence of provider-specific care and types of services provided. Changes in the prescription of specific medication classes (ie, nonsteroidal anti-inflammatory drugs [NSAIDs], muscle relaxants, nonnarcotic and narcotic analgesics) were also investigated.

RESULTS

Overall rate for outpatient treatment for nonspecific back pain in the US population was relatively stable over the decade (4.48% in 1987, 4.53% in 1997, p=.85). Among those receiving care, the proportion receiving physician care increased from 64% in 1987 to 74% in 1997 (p<.001), whereas those obtaining care from physical therapists increased from 5% to 9% during the same time period (p<.01). The proportion of respondents receiving NSAIDs, muscle relaxants, nonnarcotic analgesics and narcotic analgesics remained stable. However, the mean number of patient visits in which these medications were prescribed increased from 2.0 to 3.9 over the decade (p<.001). The proportion of individuals receiving chiropractic care (p<.01) and X- rays (p<.001) were lower in 1997 than 1987.

CONCLUSIONS

The national pattern of health care for nonspecific low back pain observed in the present study serves as a basis for future investigations into the management of this major public health problem. Findings suggest that perhaps a duplication of care is partly responsible for the high degree of health care utilization in this population.

Identifying barriers to recovery from work related upper extremity disorders: use of a collaborative problem solving technique

Improving health and work outcomes for individuals with work related upper extremity disorders (WRUEDs) may require a broad assessment of potential return to work barriers by engaging workers in collaborative problem solving. In this study, half of all nurse case managers from a large workers' compensation system were randomly selected and invited to participate in a randomized, controlled trial of an integrated case management (ICM) approach for WRUEDs. The focus of ICM was problem solving skills training and workplace accommodation. Volunteer nurses attended a 2 day ICM training workshop including instruction in a 6 step process to engage clients in problem solving to overcome barriers to recovery. A chart review of WRUED case management reports (n = 70) during the following 2 years was conducted to extract case managers' reports of barriers to recovery and return to work. Case managers documented from 0 to 21 barriers per case (M = 6.24, SD = 4.02) within 5 domains: signs and symptoms (36%), work environment (27%), medical care (13%), functional limitations (12%), and coping (12%). Compared with case managers who did not receive the training (n = 67), workshop participants identified more barriers related to signs and symptoms, work environment, functional limitations, and coping (p < .05), but not to medical care. Problem solving skills training may help focus case management services on the most salient recovery factors affecting return to work.

Integrated case management for work-related upper-extremity disorders: impact of patient satisfaction on health and work status

An integrated case management (ICM) approach (ergonomic and problem-solving intervention) to work-related upper-extremity disorders was examined in relation to patient satisfaction, future symptom severity, function, and return to work (RTW). Federal workers with work-related upper-extremity disorder workers' compensation claims (n = 205) were randomly assigned to usual care or ICM intervention. Patient satisfaction was assessed after the 4-month intervention period. Questionnaires on clinical outcomes and ergonomic exposure were administered at baseline and at 6- and 12-months postintervention. Time from intervention to RTW was obtained from an administrative database. ICM group assignment was significantly associated with greater patient satisfaction. Regression analyses found higher patient satisfaction levels predicted decreased symptom severity and functional limitations at 6 months and a shorter RTW. At 12 months, predictors of positive outcomes included male gender, lower distress, lower levels of reported ergonomic exposure, and receipt of ICM. Findings highlight the utility of targeting workplace ergonomic and problem solving skills.

Individual and combined impacts of biomechanical and work organization factors in work-related musculoskeletal symptoms

BACKGROUND

Investigations of work-related low back (LB) and upper extremity (UE) disorders have increasingly utilized multivariable models that include biomechanical/physical and work organization factors. However, the nature of any interactive effects is not well understood.

METHODS

Using questionnaires, high and low exposure groups for biomechanical/physical factors, cognitive demands, cognitive processing, interpersonal demands, participatory management, skill discretion, and time pressure for 289 individuals (U.S. Marines) were identified. Musculoskeletal symptom status was also determined by questionnaire. Individual and biomechanical-psychosocial combinations were examined in adjusted multivariable logistic regression analyses.

RESULTS

Time pressure was associated with both LB and UE symptoms (odds ratio(s) (OR) range = 2.13-3.09), while higher biomechanical exposures were risk factors for LB symptoms (OR = 2.07; 95% confidence intervals (CI): 1.00-4.35) and concurrent LB and UE symptoms (OR = 2.80; CI: 1.35-5.83). Greater risks for concurrent LB and UE symptoms were indicated for combinations involving higher biomechanical exposure and: time pressure (OR = 2.21; CI: 1.19-4.10); cognitive demands (OR = 2.25; CI: 1.23-4.09); cognitive processing (OR = 2.08; CI: 1.16-3.75); interpersonal demands (OR = 2.44; CI: 1.35-4.41); participatory management (OR = 2.50; CI: 1.30-4.81). Results did not suggest any interaction between biomechanical and work organization factors.

CONCLUSIONS

While no synergism was indicated, the present findings emphasize the need to consider both biomechanical factors and specific work organization factors, particularly time pressure, in reducing musculoskeletal-related morbidity.