造型作业体力负荷接触评估

目的以姿势观察和表面肌电分析相结合,分析造型作业体力负荷暴露特征。方法以OWAS方法观察造型作业姿势5074人次,并分析5个造型作业周期4对躯干肌的表面肌电信号的周期间变异性、躯干肌活动协调性、双侧对称性和典型动作肌电活动。结果姿势观察表明背部非正中姿势占87．7％,其中14．7％为扭腰姿势;13．2％的时间承受10k以上的负荷;手工作业成分如铲、压、搬、推拉和放物合计55．2％。不同造型周期间平均肌电活动变异性很小,而双侧不对称性（约60％）很高;相对其他躯干肌,竖脊肌肌电活动最高,平均超过20％MVC,某些动作时高达50％MVC。结论躯干肌活动不协调、竖脊肌过劳和不对称用力是造型作业躯干肌活动的主要特征,造型作业工作腰背痛高发与其有关。     

Effects of educational intervention on joint angles of the trunk and lower extremity and on muscle activities during patient-handling tasks

Objective  The objective of this study was to examine the effects of educational intervention on joint angles of the trunk and lower extremity and on muscle activities during patient-handling task. Methods  Thirty-two subjects (17 males and 15 females) volunteered for the study. They were classified into three groups: intervention group 1, comprised of first grade physical therapist students; control group, which included first grade occupational therapist students; intervention group 2, which comprised third grade physical therapist students. The educational intervention during the experimental period consisted of: (1) 12 regular classes and short-term clinical practice for the students of intervention group 1; (2) long-term clinical practice, relating to patient-handling task, for the students of intervention group 2. The following experiments were repeated before and after the educational intervention. Each subject was asked to transfer a male (55 kg) from one chair to a second chair (left to right) and then back again to the original chair (right to left). The flexion angles of the trunk, hip and knee joints were quantified by means of the dynamic three-dimensional biomechanical analysis. Muscle activities (% maximum voluntary contraction, %MVC) of biceps brachii, trapezius, rectus femoris and erector spinae muscles were measured using surface electromyography (EMG). The effects of group, gender, measurement time and side on joint angles of trunk and lower extremity, %MVC of four muscle activities and transfer time were assessed. Results  Although the EMG analysis could not clearly demonstrate any reduction of physical load to the low back, the flexion angles of the hip and knee joints of student subjects during the patient-handling task became larger and that of the trunk became smaller in the group given the educational intervention. Conclusion  The finding of this study suggests that the posture of the study subjects changed to the squat lifting method, which is preferable for reducing the physical load to the lower back, as a result of the educational intervention.     

Physical capacity in relation to low back, neck, or shoulder pain in a working population

Aims

To investigate the longitudinal relation between physical capacity (isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine) and low back, neck, and shoulder pain.

Methods

In this prospective cohort study, 1789 Dutch workers participated. At baseline, isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine were measured in the pain free workers, as well as potential confounders, including physical workload. Low back, neck, and shoulder pain were self‐reported annually at baseline and three times during follow up.

Results

After adjustment for confounders, Poisson generalised estimation equations showed an increased risk of low back pain among workers in the lowest sex specific tertile of performance in the static back endurance tests compared to workers in the reference category (RR = 1.42; 95% CI 1.19 to 1.71), but this was not found for isokinetic trunk lifting strength or mobility of the spine. An increased risk of neck pain was shown for workers with low performance in tests of isokinetic neck/shoulder lifting strength (RR = 1.31; 95% CI 1.03 to 1.67) and static neck endurance (RR = 1.22; 95% CI 1.00 to 1.49). Among workers in the lowest tertiles of isokinetic neck/shoulder lifting strength or endurance of the shoulder muscles, no increased risk of shoulder pain was found.

Conclusions

The findings of this study suggest that low back or neck endurance were independent predictors of low back or neck pain, respectively, and that low lifting neck/shoulder strength was an independent predictor of neck pain. No association was found between lifting trunk strength, or mobility of the spine and the risk of low back pain, nor between lifting neck/shoulder strength or endurance of the shoulder muscles and the risk of shoulder pain.     

Strenuous working conditions and musculo-skeletal disorders among female hospital workers

The relations between working conditions and various aspects of health among female hospital workers were studied in 26 departments of large hospitals in the Paris area in 1986; 90% of the workers of these departments filled in a questionnaire about their working conditions, sociodemographic characteristics and health in the previous 12 months and attended a medical examination. The study sample included 1505 women. The main cause of sick leave was musculoskeletal disorders and affected 16% of the women. Back pain was described by 47% of the women, and treatment for musculo-skeletal disorders by 28%. Three working conditions were considered to characterize the posture at work: standing more than six hours a day, bending over more than ten times per hour, and maintaining an uncomfortable posture. A cumulative posture index was constructed by adding for each worker the number of the working conditions to which she had been exposed. A cumulative lifting index was constructed in a similar way from the four following characteristics: lifting weights of more than 15 kg, lifting patients more than ten times a day, making beds normally or often, and pushing beds or trolleys more than ten minutes a day. A mixed index was then constructed associating the two previous ones. The relations between these indexes and musculoskeletal disorders (MSD) were studied after adjustment for potential confounders such as age, obesity, number of children, travel duration, sport practice, occupational level, number of years in the occupation, previous attack of back pain, and mental health (assessed by the score to the general health questionnaire). The logistic regressions of MSD indicators on the mixed index and other risk factors showed that MSD was about twice as frequent among women with a maximal load in posture and/or in lifting than among women with no more than one medium index (tiring posture or lifting). These facts support the necessity for improvement of the work load in hospitals.     

Association Between Whole-Body Vibration and Low-Back Disorders in Farmers: A Scoping Review

Introduction: Low-back disorders (LBDs) are the most common musculoskeletal problem among farmers, with higher prevalence rates than in other occupations. Farmers who operate tractors and other types of machinery can have substantial exposure to whole-body vibration (WBV). Although there appears to be an association between LBDs and WBV, the causal relationship is not clear. Objective: This scoping review investigates the association between WBV and LBDs specifically among farmers. Methods: Nine databases were searched using groups of terms for two concepts: ‘farming’ and ‘low back disorder’. Screening, data extraction, and quality assessment were performed by two reviewers independently. Included studies met the following criteria: focused on adult farmers/agricultural workers; assessed exposure to operating farm machinery such tractor, combine, or all-terrain vehicle; assessed LBDs as an outcome; and reported an inferential test to assess the relationship between WBV and LBD. Results: After 276 full texts screened, 11 articles were found to analyze WBV as a risk factor for LBDs. Three were case–control, five cross-sectional, and three retrospective cohorts. Four studies showed no association between WBV and LBDs, four a positive association, and three results were mixed depending on the exposure/outcome measure. Conclusion: A firm conclusion is difficult due to heterogeneity in, LBDs definition, type of farm commodity, study design, and statistical strategy. Direct comparisons and synthesis were not possible. Although retrospective cohort studies tended to show a relationship, future studies with a prospective cohort design could help clarify this association further.     

High physical work load and low job satisfaction increase the risk of sickness absence due to low back pain: results of a prospective cohort study

Objective: To determine whether physical and psychosocial load at work influence sickness absence due to low back pain.

Methods: The research was a part of the study on musculoskeletal disorders, absenteeism, stress, and health (SMASH), a 3 year prospective cohort study on risk factors for musculoskeletal disorders. Workers from 21 companies located throughout The Netherlands participated in the part of this study on sickness absence due to low back pain. The study population consisted of 732 workers with no sickness absences of 3 days or longer due to low back pain in the 3 months before the baseline survey and complete data on the reasons for absences during the follow up period. The mean (range) period of follow up in this group was 37 (7–44) months. Physical load at work was assessed by analyses of video recordings. Baseline information on psychosocial work characteristics was obtained by a questionnaire. Data on sickness absence were collected from company records. The main outcome measure was the rate of sickness absences of 3 days or longer due to low back pain during the follow up period.

Results: After adjustment of the work related physical and psychosocial factors for each other and for other potential determinants, significant rate ratios ranging from 2.0 to 3.2 were found for trunk flexion, trunk rotation, lifting, and low job satisfaction. A dose-response relation was found for trunk flexion, but not for trunk rotation or lifting. Non-significant rate ratios of about 1.4 were found for low supervisor support and low coworker support. Quantitative job demands, conflicting demands, decision authority, and skill discretion showed no relation with sickness absence due to low back pain.

Conclusions: Flexion and rotation of the trunk, lifting, and low job satisfaction are risk factors for sickness absence due to low back pain. Some indications of a relation between low social support, either from supervisors or coworkers, and sickness absence due to low back pain are also present.

     

Back disorders and nonneutral trunk postures of automobile assembly workers.

A case-referent study was conducted in an automobile assembly plant to evaluate the health effect of trunk postures, such as bending and twisting, that deviate from anatomically neutral. Cases of back disorders were all those of workers who reported back pain to the medical department in a ten-month period and met the severity criteria of an interview. The referents were randomly selected workers free of back pain according to medical department records, an interview, and an examination. For each of the final 95 cases and 124 referents, the job was analyzed for postural and lifting requirements with a video recording and software analysis system by analysts blinded to the case/referent status. Back disorders were associated with mild trunk flexion [odds ratio (OR) 4.9, 95% confidence interval (95% CI) 1.4-17.4], severe trunk flexion (OR 5.7, 95% CI 1.6-20.4), and trunk twist or lateral bend (OR 5.9, 95% CI 1.6-21.4). The risk increased with exposure to multiple postures and increasing duration of exposure.     

Can Chinese MAWL be used for designing manual handling tasks?

Previous studies have employed collected MAWL (maximal acceptable weight of lift) data as criteria for designing manual handling tasks because MAWL relates to one's limitation of muscle strength. However, whether the Chinese MAWL can still be used for job design is questionable because the Chinese are relatively weaker than Western subjects in their upper extremities. To clarify this, in the present study 24 male Chinese subjects psychophysically determined their MAWL and MAWLo (maximal acceptable weight of lower) under task conditions of three lifting frequencies and two lifting ranges. The results indicated that subjects' MAWLo were significantly lower than their MAWL, especially when infrequent tasks were performed (including tasks of one time maximum and one lift (lower)/min, all p<.05). This could be attributed to a relatively disadvantageous position in the upper extremities at the beginning stage of these lowering tasks. This finding strongly implies that it is not enough to consider only Chinese MAWL when designing manual handling tasks; MAWLo data should not be ignored.     

表面肌电和心电评价手工搬举作业工间休息的实验研究

目的 研究手工搬举作业的工间休息时间.方法 30名大学生志愿者从事模拟的蹲举、背举和半蹲举手工搬举作业,分别测定他们在工间休息时左、右侧胸10(LT10、RT10)和腰3(LL3、RL3)竖脊肌的肌电及其心电,分析最大随意收缩肌电百分比(percentage of maximum voluntary electrical activation,MVE%)、中位频率(median frequency,MF)及心率(heart rate,HR),评价负荷恢复状况.结果 15 min工间休息内,男性被测试者4个部位竖脊肌肌电MVE%均在5 min内恢复至静息水平,且91.8%在2 min内恢复;而女性被测试者除RL3和LL3 MVE%在半蹲举活动后未恢复外,其余肌肉MVE%均在3 min内恢复,且67.8%在2 min内恢复.男性被测试者除RL3竖脊肌肌电MF在蹲举和背举后未恢复外,其余MF均在10 min内恢复,且74.9%在2 min内恢复.女性被测试者竖脊肌肌电MF均在8 min内恢复,且83.4%在2 min内恢复.在3种搬举活动结束后20 min休息时段内,男、女被测试者各部位竖脊肌MVE%和MF均恢复到静息水平;男、女被测试者心率分别在14、5 min恢复到静息水平.结论 在负荷为25%MVC,持续时间为4.5 min的3种搬举活动中,就局部肌肉负荷的恢复而言,15 min休息仅保证绝大多数竖脊肌恢复;就全身负荷恢复而言,15 min休息可保证心率完全恢复到静息水平.

Abstract：

Objective To investigate the recovery duration of manual lifting tasks. Methods 30 college student volunteers with gender equally distributed were involved in the simulated stoop-, squart- and semisquart-lifting tasks in the laboratory. Signals of electromyography ( EMG ) at the back muscles ( left and right thorax m. erector spinae, LT10 and RT10; left and right lumbar m. erector spinae, LL3 and RL3) and electrocardiography (ECG) were recorded during the rest intervals. The percentage of maximum voluntary electrical activation( MVE% ), EMG median frequency (MF), and heart rate (HR) were analyzed to predict the recovery time required. Results During the break, MVE% at 4 back muscles of all the male subjects were recovered to resting level within 5 minutes and 91.8% were within 2 minutes. Except for Rt3 after squat- and stoop-lifting task, the MVE% of female subjects went back to resting level within 3 minutes and 67.8% were within 2 minutes. The MF of male subjects were recovered in 10 minutes and 74.9% within 2 minutes, with the exception of RL3 after stoop- and squat- lifting tasks. All the female MF were recovered in 8 minutes and 83.4% were within 2 minutes. However, during the last 20 minute break after the lifting tasks, the MVE% and MF of all male and female subjects were recovered, while HR came back to resting level within 14 and 5 minutes, respectively. Conclusions For the three manual lifting tasks with 25% MVC workload lasting for 4.5 min, a break of 15 minutes is sufficient for most erectors spinae to recover from local muscle load. However, in terms of the HR, a break of 15 minutes is enough for the recovery of systematic load.     

Cumulative Low Back Load at Work as a Risk Factor of Low Back Pain: A Prospective Cohort Study

Purpose Much research has been performed on physical exposures during work (e.g. lifting, trunk flexion or body vibrations) as risk factors for low back pain (LBP), however results are inconsistent. Information on the effect of doses (e.g. spinal force or low back moments) on LBP may be more reliable but is lacking yet. The aim of the present study was to investigate the prospective relationship of cumulative low back loads (CLBL) with LBP and to compare the association of this mechanical load measure to exposure measures used previously. Methods The current study was part of the Study on Musculoskeletal disorders, Absenteeism and Health (SMASH) study in which 1,745 workers completed questionnaires. Physical load at the workplace was assessed by video-observations and force measurements. These measures were used to calculate CLBL. Furthermore, a 3-year follow-up was conducted to assess the occurrence of LBP. Logistic regressions were performed to assess associations of CLBL and physical risk factors established earlier (i.e. lifting and working in a flexed posture) with LBP. Furthermore, CLBL and the risk factors combined were assessed as predictors in logistic regression analyses to assess the association with LBP. Results Results showed that CLBL is a significant risk factor for LBP (OR: 2.06 (1.32–3.20)). Furthermore, CLBL had a more consistent association with LBP than two of the three risk factors reported earlier. Conclusions From these results it can be concluded that CLBL is a risk factor for the occurrence of LBP, having a more consistent association with LBP compared to most risk factors reported earlier.     

运动疗法治疗慢性腰腿痛效果分析

目的比较腰椎间盘突出与腰椎间管狭窄运动疗法的治疗效果。方法采取自愿报名的办法,在社区选择明确诊断的腰椎间盘突出患者和腰椎间管狭窄患者各60例,进行腰背部活动度、腰背部肌力和腰背部肌肉耐力训练,时间1年,干预前后分别进行疼痛强度、身体损害程度、生活功能障碍指数评定。结果运动治疗后,腰椎间盘突出患者在疼痛程度、身体损害程度、活动能力、社会参与能力方面明显改善,腰椎间管狭窄患者改善不明显。结论运动疗法可以巩固腰椎间盘突出症的治疗效果,是在社区进行推广,而运动疗法对于腰椎间管狭窄者效果不明显。     

Effects of drop out in a longitudinal study of musculoskeletal disorders

OBJECTIVES—The drop out rates in different longitudinal studies of musculoskeletal disorders range between 7% and 57%, and little is known about the characteristics of the subjects who dropped out. The aim was to analyse various consequences of drop out in a longitudinal study of musculoskeletal disorders and occupational risk factors during 1969-97.
METHOD—Data about occupational conditions and health in 1969 and in 1993 were analysed. Differences between those who participated throughout (participants) and drop out subjects in these analyses formed the basis for recalculations of earlier reported analyses of associations between occupational conditions and low back pain. In the recalculation the data were weighted to compensate for the differences.
RESULTS—More female and male drop out subjects than participants in 1993 had monotonous work, fewer women and more male drop out subjects had heavy lifting in 1969. In 1997, more female and male drop out subjects had had heavy lifting and low stimulation at work in 1993. At both occasions, there were differences between the drop out subjects and participants in occurrence of musculoskeletal disorders. The weighted analyses resulted in changes in risk ratio of 0.1-0.2.
CONCLUSIONS—Differences in occupational conditions and health among participants and drop out subjects in a longitudinal study of musculoskeletal disorders and occupational risk factors during 1969-97 did not markedly influence the risk ratios.


Keywords: panel study; non-response; survey method; methodological study     

Evaluation of a swiveling seat to reduce the physical load on forklift drivers]

Many forklift drivers have musculoskeletal disorders such as low back pain related to poor work posture and whole-body vibration. With a forklift operator's seat capable of 45-degree swiveling, we evaluated the physical reduction in the load in 10 subjects working in a back-looking position by means of surface electromyography (EMG) and the angle of rotation of the trunk and neck regions. The amplitude of surface EMG on the trapezius, erector spinae, and latissimus dorsi muscles in looking back or maintaining a back-looking position decreased with a swiveling seat compared to the stationary seat. Nevertheless, there was little alleviation of the amplitude of surface EMG on the sternocleidomastoid muscle in maintaining a back-looking posture and no decrease in looking back. The angle of rotation of the trunk maintaining a back-looking position was decreased greatly with the swiveling seat, but no decrease in the rotation angle of the neck was seen. Our study suggests that a swiveling seat is effective in reducing the physical load on the forklift driver during back-looking operations, and this may lead to the prevention of low back pain.     

Reaction of the cardiovascular system with lifting and lowering of loads

It was investigated the influence of lifting and lowering of loads on the systolic, diastolic blood pressure and on the heart rate. Male subjects had to move 20 kg and female subjects 10 kg in different ways (2 different working frequencies and 3 back bending angles). At higher working frequencies the heart rate in men and women was in the range of the physical endurance limit. An important finding was the difference in the diastolic blood pressure response during lifting and lowering of loads with the higher working frequency in men.     

Matching FCE Activities and Work Demands: An Explorative Study

OBJECTIVES: to explore to what extent the standardized Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) can be matched with observed work demands in workers with chronic low back pain, and, secondly, to explore whether this match can predict sick leave in the year after rehabilitation treatment. METHODS: An explorative prognostic cohort study with a one-year follow-up (four, eight and twelve months after baseline) was performed (n = 18). Demographics, back complaints and FCE performance were assessed at baseline. In addition, a workplace assessment (WPA) was performed. Eleven FCE activities were matched with work demands. Sick leave associated with low back pain and physical and psychosocial work demands were assessed during follow-up. RESULTS: Seven activities could be directly matched with WPA data. (Carrying, pushing, pulling, crouching, kneeling, static forward bending, and dynamic bending and rotating.) For some workers, difficulties existed in matching three of the activities (pushing, pulling and crouching). One activity (lifting) could indirectly be matched with WPA data. One activity (walking) could not be matched with WPA data. Two activities (sitting, standing) were excluded from analyses due to practical limitations. No relation was found between FCE performance, work demands, and sick leave during follow-up. CONCLUSIONS: Seven FCE activities could be directly matched with work demands. However, not all observed work demands could be matched with IWS FCE activities in the eighteen occupations studied. This quantitative and standardized way of assessing work-related disability is not sufficient to predict work ability and sick leave at the present time.     

某汽车公司铸造厂工人腰背痛的危险因素分析

目的 通过横断面流行病学记查,寻找汽车铸造厂作业工人腰背痛的主要危险因素,为此类疾患的预防提供科学依据.方法 在某汽车公司铸造厂对1340名工人进行腰背痛和劳动负荷问卷调查,利用logistic回归进行危险因素分析.结果 铸造厂工人的腰背痛年患病率为58.9%,其中铸造、物流和造型工种工人腰背痛年患病率较高,分别为64.6%、64.6%和62.5%.以不适体位搬举、大幅度弯腰、弯腰与转身并存及搬运重物这些负荷因素导致患腰背痛危险性最高,其OR值分别为2.085、1.961、1.967和1.956.各个危险因素在不同工种中的分布不同.多元logistic同归分析表明,搬运重物、不适体位搬举、大幅度弯腰、弯腰与转身并存及工龄和性别均被选人模型.结论 手工搬运重物、不良劳动姿势或二者同时存在是导致腰背痛的首要危险因素,应从这方面入手,加强工效学干预研究,减少此类疾患.

Abstract：

Objective To study the main risk factors of low back pain of workers in a foundry factory of the automobile company using cross sectional epidemiological investigation, and to provide scientific base for preventing the disorder. Methods The low back pain and work loads of 1340 workers in a foundry factory of the automobile company were investigated using questionnaire, and logistic regression analysis was used to analyze the risk factors. Results The one-year morbidity of low back pain in workers was 58.9%the morbidities of low back pain in workers engaged in foundry, transportation and modeling were 64.6 %, 64.6 % and 62.5 %, respectively. The lifting with squat postures, bending trunk heavily, bending trunk with twisting and moving the heave objects were found to be the most dominant risk factors for low-back pain, the OR values were 2.085, 1.961, 1.967 and 1.956, respectively. The distributions of risk factors were different among the different jobs. The logistic regression analysis showed that moving the heave objects, lifting with squat postures, bending trunk heavily, bending trunk with twisting existed simultaneously, also the work years and gender were the risk factors. Conclusion The manual moving heave objects, awkward working posture or both were the most important risk factors for low-back pain. The intervene ergonomic study should be performed in future to reduce the morbidity of low-back pain.     

Effects of sinusoidal whole-body vibration on the lumbar spine: the stress-strain relationship

Summary The aim of this experimental study was to estimate the strain in the lumbar spine due to whole-body vibration (WBV). Four male subjects were exposed to vertical sinusoidal WBV with frequencies ranging from 1 to 15 Hz at two intensities (I₁ = 1.5 ms^–2 rms; I₂ = 3.0 ms^–2 rms). The compressive forces acting on the disc L3-4 during the extreme values of acceleration were predicted on the basis of anthropometric data, EMG of back muscles and the acceleration of the upper trunk, using a simple biomechanical model. The estimated mechanical activity of back muscles was not able to protect the spine under many exposure conditions. The highest compressive forces were predicted for WBV with 7.5, 8 and 4.5 Hz. The results suggest the possibility of fatigue failures at the endplates of lumbar vertebrae after intense long-term exposure to WBV.The authors gratefully acknowledge the help and assistance of G. Menzel, R. Vizcaino, and A. Weissmüller     

Predicting post treatment spinal strength and flexibility in work-disabled low back pain patients

This study examined whether posttreatment trunk strength and flexibility could be predicted from initial trunk strength and flexibility, age, gender, pain severity, diagnosis, length of work disability, return-to-work expectations, anxiety, and fear of reinjury among a group of 96 injured workers with chronic occupational low back pain who completed a multidisciplinary work rehabilitation program. The results indicate that initial average torque in trunk extension, age, gender, and average pain severity contribute significantly to prediction of final average torque in trunk extension. Initial average torque in trunk flexion, age, and gender contributed significantly to prediction of final average torque in trunk flexion, and age and initial range of motion contributed significantly to the prediction of final trunk range of motion. The results indicate that prediction of trunk strength and range of motion can be accomplished from measures of trunk strength and flexibility and pain obtained prior to the onset of rehabilitation. Psychological measures were not predictive of posttreatment trunk strength and flexibility. The ability to predict posttreatment trunk strength should facilitate clinical decision making in these complex cases.     

Perceived exertion of physical effort for various manual handling tasks

Ten trained male students between 18 and 28 years of age participated in a study, designed to determine the relationship between perceived exertion and physiological costs of exertion during various manual lifting and lowering tasks. Perceived exertion was defined as one's subjective rating of the intensity of work being performed. Five subjects performed lifting tasks and another five performed lowering tasks. Weight of load lifted or lowered (6.8, 13.6, 20.5 kg), frequency of lift or lower (3, 6, 9 times/min), height of lift or lower (floor to 76 cm, 76 to 127 cm, floor to 127 cm), box width (38, 66 cm), box length (38, 66 cm) and angle of twist of the body (0 degree, 90 degrees) were the independent variables studied. Heart rate, oxygen consumption, and ratings of perceived exertion (RPE) were the response measures. RPE was found almost linearly related to heart rate and oxygen consumption when lifting or lowering loads. For lifting tasks, the coefficient of correlation between RPE and heart rate was 0.673. In the case of lowering tasks, this coefficient was 0.604. When oxygen consumption was considered, the corresponding coefficients for lifting and lowering were 0.734 and 0.619, respectively. The correlation of RPE with the physiological response variables indicates that the severity of manual materials handling tasks in industry can be evaluated quickly and inexpensively by using perceived exertion ratings (RPE).