Fatigue and low-back pain of freight-container tractor drivers. Correlation with ergonomic factors

An ergonomic checklist was prepared to examine safety and comfort of freight-container tractors. With this checklist, 533 tractor drivers were asked to evaluate the tractors to which they were exclusively assigned. In order to check the objectivity and the validity of the results, the correlation between the evaluation of the items on the checklist and the corresponding dimensions on 10 tractors was studied. Also, a multivariate analysis based on quantification theory was done to examine the correlation between the ergonomic items on the checklist and the drivers' low-back pain or fatigue symptoms of the upper and lower extremities. The main results were as follows: 1) A high correlation was observed between the evaluation of items on the checklist and the corresponding dimensions of the tractors. 2) Many items on the checklist received a poor evaluations, indicating that there are many ergonomic problems with freight-container tractors. 3) The analysis by the quantification theory showed high correlation ratios between the items in the checklist and the drivers' fatigue symptoms of the upper and lower extremities. These correlation ratios were: arm fatigue when holding the steering wheel (0.51), arm fatigue in operating the gearshift lever (0.65), arm fatigue from opening and closing the windows (0.46), leg fatigue from operating the pedals (0.58), and low-back pain during the last two months (0.31). These showed that more than 50% of the fatigue symptoms could be explained by the ergonomic aspects of the tractors. 4) The rate of dissatisfaction with the current tractors was 82.9%. According to the analysis by the quantification theory, the correlation ratio between the items in the checklist and the rate of dissatisfaction for the current tractors was 0.66. 5) The foregoing results indicate that ergonomic improvement of the freight-container tractors is a matter of urgency. This should reduce the drivers' fatigue and elevate the rate of satisfaction with the tractors. 6) However, for the prevention of the drivers' low-back pain and fatigue symptoms, improvement of the ergonomic conditions of the tractors and the drivers' working conditions must be undertaken at the same time.     

The labor of freight-container tractor drivers and low back pain. Correlation with whole-body vibration exposure

In order to determine the causal factors of low back pain (LBP) which prevails among freight-container tractor drivers, vibration measurements of the seat of ten freight-container tractors and one heavy truck, a survey on the daily working hours of 240 tractor drivers for a month, and a time study of work on 28 person-days were conducted. Vibration measurement was made under routine conditions on paved public roads for 40 km under laden and unladen conditions. For the evaluation of vibration exposure, ISO 2631 was used. With the freight-container tractors, the mean vibration levels were high in X and Z directions, particularly in X direction. In the heavy truck, the vibration level was consistently higher in Z direction. According to the evaluation made by ISO 2631, the X component of the vibration was found to be serious. The magnitude of the vibration level was greatly influenced by the condition of the road surface with bridges tending to produce a high level of vibration. Vibration levels of the new model tractors were not necessarily always lower than that of the old models. It was estimated from the foregoing results and the time study that in more than 90% of the drivers the daily exposure time (i.e. driving hours) exceeded the allowable exposure time of fatigue-decreased proficiency boundary (FDP), and in about one-third of the drivers the allowable exposure time of exposure limit (EL) was exceeded. These results suggest that long exposure to severe vibration during work is one of the possible causal factors of LBP of freight-container drivers.     

Factors associated with medical care-seeking due to low-back pain in scaffolders

BACKGROUND: Few studies have demonstrated the consequences of having back pain and the mechanisms underlying decisions to seek medical care. This study aimed to assess the prevalence of back pain and other musculoskeletal complaints and to identify factors that determine specific type of care-seeking due to back pain among scaffolders. METHODS: A cross-sectional study was conducted among 323 scaffolders. A questionnaire was used to collect data on musculoskeletal complaints and type of medical care sought. Logistic regression analysis was performed to study the risk factors for care-seeking for LBP, estimating Prevalence Ratios (PR) as a measure of association. RESULTS: The prevalence of musculoskeletal complaints was high. Severe back pain was reported by 28% of the scaffolders, LBP with sciatic pain by 23%, with sickness absence by 21%, with disability by 21%, and chronic back pain by 14%. Back pain was often accompanied by complaints of neck, shoulder, or knee. A general practitioner was sought by 44% of the workers with LBP, a physiotherapist by 22%, an occupational physician by 20%, and a specialist by 11%. The nature and severity of back pain seemed to determine the decision to visit the GP. Irradiating pain and sickness absence were the strongest predictors for seeking medical care and being referred to a specialist or physiotherapist. CONCLUSION: The particular definition of back pain and the selection process of workers with LBP may partly determine the findings on work-related risk factors and health care utilization.     

Subjective pain and tenderness in low back among care workers in relation to work load and daily life]

Five hundred and fifty-two care-workers aged 20 to 60 years, who worked at six custodial-care homes, were examined to clarify the relationship between subjective pain and tenderness in the low back, together with the factors affecting occupational low back pain. Subjects who were diagnosed as having tenderness in the low back by one medical practitioner at the time of health examinations, and those who reported the presence of low back pain in self-rating questionnaires were defined as those with "objective" and "subjective" low back pain, respectively. Complaints concerning workloads and daily life, as well as musculoskeletal and systemic symptoms, were inquired of in the self-rating questionnaires; the former complaints were compiled into four factors representing "environmental load at work," "physical load at work," "mental load at work," and "daily life" by the factor analysis. The corresponding rates in subjective and objective low back pains were 67.0% in 188 male care workers and 70.9% in 364 female care workers. In males and females, "physical load at work" was positively related to subjective low back pain (P < 0.05) with the use of the multiple logistic regression analysis including all the causal and confounding factors. Musculoskeletal symptoms in females were also positively related to subjective and objective low back pain (P < 0.05). These data suggest that subjective low back pain clearly reflects the problem of occupational low back pain as a whole, and that low back pain is mainly related to the physical load at work in care workers.     

Seat inclination, use of lumbar support and low-back pain of taxi drivers

OBJECTIVES: Epidemiologic evidence supporting optimal seating is limited and inconsistent. This cross-sectional study was conducted to examine the association between seat inclination, use of lumbar support, and the prevalence of clinically significant low-back pain among taxi drivers METHODS: A digital inclinometer was used to measure inclinations of seat surfaces (theta(seat)) and backrests (theta(back)), and calculate the back-to-thigh angle (theta(back-thigh)). Structured interviews were conducted to gather information on the use of lumbar support and the prevalence of low-back pain that had led to medical attention or absence from driving in the past month. A multiple logistic regression analysis was used to estimate the prevalence odds ratio (OR) with adjustment for age, body mass index, professional seniority, monthly driving hours, and the intensity of exposure to whole-body vibration. RESULTS: Among 224 drivers, the mean theta(seat), and theta(backrest) were 14.5 (SD 9.6) and 95.1 (SD 2.7) degrees, respectively, resulting in theta(back-thigh) of 80.6 (SD 9.3) degrees. Fifty-five percent used a lumbar support regularly, but 25% reportedly had significant low-back pain. The prevalence of low-back pain was 23% among those with theta(back-thigh) <86 degrees, 37% for those with a theta(back-thigh) of 86 approximately 91 degrees, and 9% for a theta(back-thigh) of >91 degrees. The adjusted OR comparing those with a theta(back-thigh) of < or = 91 degrees to those with a theta(back-thigh) of >91 degrees was 5.11 [95% confidence interval (95% CI) 1.07 approximately 24.4]. For regularly using drivers versus those not using lumbar support, the prevalence of low-back pain was 18% versus 34%, with an adjusted OR of 0.33 (95% CI 0.16 approximately 0.68). Neither theta(seat) nor theta(backrest) alone was significantly associated with low-back pain. CONCLUSIONS: The epidemiologic observation of this study was consistent with the results of prior biomechanical studies on appropriate seat inclinations and the use of lumbar support. Prospective studies are needed to confirm the true beneficial effects of these seating parameters.     

Occupational cervicobrachial disorder (OCD) of nursery school teachers based on subjective symptoms related to OCD

To clarify the association of occupational cervicobrachial disorder (OCD), with labor conditions, and personal situation, a questionnaire study was conducted among nursery school teachers. The questionnaire was composed of subjective symptoms related to OCD (neck, shoulder, back and arm stiffness/pain), labor conditions, and whether or not the teacher had a child of her own under the age of two. Data of 793 subjects were analyzed. The results were as follows: The mean age and working period of 793 subjects were 27.6 (+/- 4.9) and 5.5 (+/- 3.2) years, respectively. Of them, 38.5% complained of right shoulder stiffness every day during the prior month, 26.5% neck stiffness, 18.8% arm stiffness, 9.6% back pain, 7.8% shoulder pain and 3.9% arm pain. The complaint rates on the left side were similar to those on the right side. The complaint rates of these subjective symptoms increased with the duration of the working period. The complaint rates of shoulder, neck and arm stiffness increased earlier than those of back stiffness, shoulder or arm pain. The complaint rates of these symptoms were highest among teachers in charge of children less than one-year-old and those in charge of four-year olds. Teachers in charge of three-year-old children had the lowest complaint rates. Subjects complaining of neck, shoulder and arm stiffness on every day worked under less favorable conditions than those without such complaints. When subjects having no children of their own under the age of two were matched in their ages and length of work history with those who have such children, the complaint rates of the two groups did not differ statistically for any of the subjective symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)     

The association between exposure to a rear-end collision and future neck or shoulder pain: a cohort study

Neck pain is the most frequently reported feature in connection with whiplash injury, but it is also a common complaint in the general population. Therefore it is crucial to include an unexposed comparison group when evaluating the association between neck pain and a previous motor vehicle crash (MVC). To determine whether exposure to a rear-end collision, without or with whiplash injury, is associated with future neck or shoulder pain, a cohort study was conducted. The study population consisted of persons covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups, without reported whiplash injury (n = 204) and with reported whiplash injury (n = 232). Two comparison groups, unexposed to MVCs, consisting of 1599 and 2089 persons, were selected with consideration taken to the age and gender distribution in the exposed subgroups. A questionnaire concerning neck or shoulder pain and other subjective health complaints was mailed to all the study subjects at follow-up in 1994, 7 years after the rear-end collision. The relative risk of neck or shoulder pain at follow-up was 1.3 (95% CI 0.8-2.0) in the exposed subjects without whiplash injury compared with the unexposed. The corresponding relative risk in subjects with whiplash injury was 2.7 (95% CI 2.1-3. 5). We conclude that there is no increased risk of future neck or shoulder pain in drivers who did not report whiplash injury in connection with a rear-end collision 7 years earlier. In drivers with reported whiplash injury, the risk of neck or shoulder pain 7 years after the collision was increased nearly three-fold compared with that in unexposed subjects.     

Studies on the progress of occupational cervicobrachial disorder by analysing the subjective symptoms of work-women in assembly lines of a cigarette factory

The Committee on Cervicobrachial Syndrome in Japan Association of Industrial Health (JAIH) made a report on the questionnaires for checking for the complaints of patients suffering from Occupational Cervicobrachial Disorder (OCD). In order to reveal how the complaints develop in the progress of OCD, we analysed the complaints of 117 workwomen in assembly lines of a cigarette factory by using the questionnaires. And the followings were made clear: 1) At the mild stage of OCD, stiffness or dullness at the neck and shoulders, and eyestrain become remarkable. 2) At the moderate stage, pain at the neck, shoulders, arms and hands, dullness at extremities, general fatigue, pain or heavy feeling in the head, increased irritability etc. become remarkable in addition to the mild stage complaints. 3) At the severe stage, pain and dullness at the back, numbness at arms and hands, hand coldness, sleep disturbance etc. become remarkable in addition to the moderate stage complaints. 4) Various sufferings in daily life such as "I want to lie down at rest time," "I lack patience to go on reading long," "It is hard for me to go on writing long," and "Fixed sitting soon tires me" become more and more frequent as the stage advances. We consider it is important in the diagnosis of OCD to pay attention to the general symptoms such as general fatigue, pain or heavy feeling in the head, increased irritability and sleep disturbance, together with complaints at the neck, shoulders, arms and hands.     

Effect of fork-lift truck driving on low-back trouble

In a population of 240 male fork-lift truck drivers who drove at least 4 h daily, the occurrence of low-back trouble was studied in relation to that of two reference groups. The participation rate of the fork-lift truck drivers was 88%. The responses to a questionnaire concerning low-back trouble were reviewed. Among the fork-lift truck drivers, a statistically significant higher occurrence of low-back trouble was reported for the year preceding the study, in comparison, according to age, to that of a reference group of 399 working men (65 against 47%); however, there was no significantly increased frequency when compared to that of a reference group of 66 unskilled male workers (65 against 51%). The fork-lift truck drivers had a significantly higher rate of absence from work within the previous year due to low-back trouble than the two reference groups (22% compared to 7 and 9%). These findings were confirmed during the follow-up year. A correlation was found between length of employment as a fork-lift truck driver and the occurrence of low-back trouble within the preceding year. It was concluded that fork-lift truck driving may be a contributory cause for low-back trouble.     

Felling work, low-back pain and osteoarthritis

Low-back pain and the occurrence of osteoarthritis were investigated among 226 lumberjacks employed in felling work for an average of 20 a. The reference group comprised 98 persons involved in either light physical work or office activities. There were no statistically significant differences between the two groups with regard to the occurrence of low-back pain and the subjective degree of low-back pain. According to the radiographic findings the lumberjacks had statistically more occurrences (62%) of disc degeneration than the referents (50%). No association between length of exposure to felling work and the prevalence of lumbar disc degeneration could be established. The occurrence of osteoarthritis in the hip and knee joints of the lumberjacks was 5 and 3% for the lumberjacks and the referents, respectively.     

Upper body quadrant pain in bus drivers

The aims of this study were to evaluate the prevalence of upper body quadrant pain among Israeli professional urban bus drivers and to evaluate the association between individual, ergonomic, and psychosocial risk factors and occurrence of neck pain. Three hundred and eighty-four male urban bus drivers were consecutively enrolled in the study. Data pertaining to work-related ergonomic and psychosocial stress factors were collected. The 12-month prevalence of neck pain was 21.2%, followed by shoulder: 14.7%, upper back: 8.3%, elbow: 3.0%, and wrist: 3.0% pain. Prevalence of neck pain was associated with uncomfortable seats (odds ratio; OR [95% confidence interval; CI]: 2.2 [1.2-4.3], back support (2.3 [1.2-4.2]), and steering wheel (2.2 [1.1-4.5]). Drivers with neck pain reported significantly higher prevalence of pain in the upper back (OR [95% CI]: 5.9 [2.7-12.9]), shoulders (8.1 [4.3-15.3]), and wrists (7.0 [2.0-21.8]) compared to drivers without neck pain. Work-related organizational stress factors were not associated with neck pain prevalence.     

Model for the work-relatedness of low-back pain

OBJECTIVES: This study aimed at developing a model for determining the work-relatedness of low-back pain for a worker with low-back pain using both a personal exposure profile for well-established risk factors and the probability of low-back pain if the worker were unexposed to these factors. METHODS: After a systematic review of the literature, the pooled prevalence of low-back pain in an unexposed population and the pooled odds ratio (OR) for each risk factor was calculated in a meta-analysis using a random effect model. An unbiased risk estimate for each risk factor was obtained by correcting the pooled OR for confounding by other risk factors. The probability of low-back pain was calculated with a logistic regression model. The input was (i) the age-dependent prevalence when not exposed and (ii) the unbiased risk estimates per risk factor of low and high exposure. The etiologic fraction was calculated to determine the level of work-relatedness. RESULTS: The pooled prevalence for low-back pain among unexposed subjects was 22%, 30%, and 34% for the <35-year, 35-to-45-year, and >45-year age categories, respectively. The pooled OR was 1.51 [95% confidence interval (95% CI) 1.31-1.74] for manual materials handling, 1.68 (95% CI 1.41-2.01) for frequent bending or twisting, 1.39 (95% CI 1.24-1.55) for whole-body vibration, and 1.30 (1.17-1.45) for job dissatisfaction. For high exposure to manual materials handling, frequent bending or twisting, and whole-body vibration, the pooled OR was 1.92, 1.93, and 1.63, respectively. CONCLUSIONS: The model is the first that estimates the probability of work-relatedness for low-back pain for a given worker with low-back pain seen by a general practitioner or an occupational health physician.     

Isoinertial functional assessment of low-back disorders in pediatric nurses: Ergonomic and rehabilitation guidelines

Low-back troubles are among the most common and most disabling occupational pathologies. It is very common in health professionals including pediatric nursing personnel. However, the problem is difficult to assess, as in many cases there is no objective origin for the complaints. Therefore, objective measures of function are of great interest. Trunk function in a population of 50 pediatric nurses was investigated with an isoinertial dynamometric device (Isostation B200). Isometric torques, unresisted ranges of motion and dynamic velocities were measured in the sagittal plane. The population was divided into three groups: those subjects with no complaints (LBP0) those with moderate low-back pain (LBP1), and those with severe low-back pain (LBP2). Forty-two (85%) of those nurses had low-back complaints, 31 moderate and 11 severe. Isometric torques and velocities enabled a good discrimination between the three groups. There were significant differences between nurses usually carrying children on right or left arm and those carrying indifferently on any arm. The latter had better performances and less low-back pain. The velocity extension to flexion ratio was significantly decreased with the existence and severity of low-back pain. Isoinertial functional assessment has a good discriminatory value in this population. It enables one to draw ergonomic guidelines for child-carrying techniques. Finally, the modifications of the extension to flexion ratio help to determine that, in this population, rehabilitation programs should focus on dynamic back muscle strengthening.     

Musculoskeletal complaints among Italian X-ray technologists

The aim of this study was to determine the prevalence of musculoskeletal complaints among X-ray technologists and to examine their relationship with physical and psychosocial factors. A cross-sectional study was performed in 2006 among 203 X-ray technologists working in 13 hospitals in the Apulia region of southern Italy. A questionnaire was used to collect data on personal characteristics, physical workload, psychosocial aspects, and the presence of musculoskeletal symptoms in the neck, shoulders, low back, hand/wrist and legs. Univariate analyses and multiple logistic regression analyses were then performed. The prevalence of complaints at any body site in the previous 12 months was 67%. Low back pain was the most commonly reported symptom (59.6%), followed by shoulder (21.2%), neck (19.7%), leg (13.8%) and hand/wrist pain (12.3%). Age was associated with low back pain, while high physical workload was associated with symptoms in the neck, low back and hand/wrist. High job demands were associated with neck and shoulder pain. Overall, our study suggests high prevalence rates of musculoskeletal complaints may exist among Italian X-ray technologists. Physical workload, psychosocial and individual factors appear to be important risk factors for musculoskeletal disorders within this occupational group.     

Prognostic factors related to recurrent low-back pain and sickness absence

OBJECTIVES: This study aimed at determining the prognostic factors related to the recurrence of low-back pain and future sickness absence due to low-back pain. METHODS: Data were used from a prospective cohort study in a working population with a 3-year follow-up period. They were collected with annual questionnaires. A generalized estimating equation model was used to study the relation between pain characteristics, individual characteristics, and work-related factors and the recurrence of low-back pain or sickness absence due to low-back pain in the following year. Adjustments were made for potential confounders. RESULTS: All the pain characteristics [odds ratios (OR) varying from 1.4 to 2.4], flexion and rotation of the upper part of the body [OR 1.6, 95% confidence interval (95% CI) 1.1-2.5], low decision authority (OR 1.6, 95% CI 1.0-2.6), and low job satisfaction (OR 1.5, 95% CI 1.0-2.3), increased the risk of recurrent low-back pain. High disability due to low-back pain (OR 2.6, 95% CI 1.2-5.7), low co-worker support (OR 4.1, 95% CI 1.6-10.5), and low job satisfaction (OR 2.4, 95% CI 1.3-4.5) were predictors of sickness absence due to low-back pain. Lifting weights did not influence the risk of recurrences or sick leave. CONCLUSIONS: According to this study, high disability due to low-back pain is a prognostic factor for recurrent low-back pain and future sickness absence due to low-back pain. In addition, the following work-related factors predict a poor prognosis of low-back pain: flexion or rotation of the trunk, low job satisfaction, low decision authority, and low social support.     

Occupational activity and prevalence of osteomuscular pain among dentists in Belo Horizonte, Minas Gerais State, Brazil: a contribution to the debate on work-related musculoskeletal disorders

The objective was to determine the prevalence of upper-limb and back pain among dentists (n = 358) and factors associated with these symptoms. Dentists were interviewed using a self-administered questionnaire containing data on sociodemographic, occupational, lifestyle, and psychosocial factors and presence, site, and characteristics of pain. Participation rate was 92.3%. 58% reported upper limb pain, with 22, 21, 20, and 17% for the arm, back, neck, and shoulder, respectively. 26% reported daily frequency and 40% classified pain as moderate or severe. In the multivariate analysis (multiple logistic regression), the factors associated with pain were: neck: anxiety/depression (OR = 2.3; CI95%: 1.2-4.5), compressor in the office (OR = 2.1; CI95%: 1.2-3.7), job satisfaction (OR = 0.3; CI95%: 0.1-0.9), and use of indirect vision (OR = 0.5; CI95%: 0.3-0.9); shoulder: income > 20 minimum wage (OR = 2.9; CI95%: 1.2-6.7), greater productivity (OR = 3.3; CI95%: 1.3-8.4), height > or = 160cm (OR = 0.3; CI95%: 0.2-0.7), and age 30-49 years (OR = 0.3; CI95%: 0.1-0.8); back: anxiety/depression (OR = 2.3; CI95%: 1.2-4.5), manual activity (OR = 0.4; CI95%: 0.2-0.9), and being married (OR = 0.5; CI95%: 0.3-0.9); arms: manual activity (OR = 1.8; CI95%: 1.0-3.2).     

Managing shoulder pain in general practice--the value of academic detailing

After low back pain and neck pain, shoulder pain is the third musculoskeletal reason for presentation to general practice, with a self reported prevalence of 16-26%. Approximately 1% of the adult population is expected to visit a general practitioner annually for shoulder pain. Shoulder complaints are more common in women and despite the fact that 50% of acute shoulder pain resolves in 8-10 weeks, many patients present with the anticipation of being referred for imaging.     

高原汽车驾驶员腰痛的病因与特征

目的 了解高原汽车驾驶员高发腰痛的原因，并对疼痛的性质和特征进行分析。方法 通过对1132名高原汽车驾驶员的问卷调查和91名驾驶员的体格检查，分析各种造成腰痛的原因和相关因素。结果 高原缺氧反应可导致驾驶员发生腰痛，并具有一定的相关性；职业行为和不良工作体位与腰痛有关；腰痛性质以酸痛为主；半数以上驾驶员腰背部有压痛点，而与腰痛肌有关的压痛点占45．61％。结论 高原汽车驾驶员腰痛的病因较为复杂，但他们的腰痛与职业有关。     

High incidence and recurrence of shoulder and neck pain in nursing home employees was demonstrated during a 2-year follow-up

OBJECTIVE: This study describes the course of shoulder and neck complaints in a working population over time. STUDY DESIGN AND SETTING: Questionnaires were administered on neck and shoulder complaints over 3 consecutive years. RESULTS: We observed 12-month incidence rates for neck and shoulder complaints of 16% to 18%, 12-month prevalence rates roughly twice as high, and 12-month recurrence rates approximately twice the prevalence rates. Each year, medical care was sought by 21% to 38% of the subjects with neck or shoulder pain, and 13% to 21% were absent from work. Although at the population level the occurrence of neck and shoulder complaints remained constant, the course of complaints within individuals demonstrated a strong episodic nature of neck and shoulder pain. Results from this study suggest that neck and shoulder complaints for most subjects run a recurrent course characterized by a strong variation in occurrence and a self-limiting course. CONCLUSION: These findings suggest that clinical trials should have a sufficiently long follow-up period to demonstrate sustainability of the therapeutic results.     

Interaction of height and mechanical loading of the spine in the development of low-back pain.

The relation of low-back pain to height and physical activity was examined among 2667 British men and women aged 20-59 years and selected from the general population. Information about occupational activities, height, and lifetime history of low-back pain was obtained from a postal questionnaire. The lifetime prevalence of low-back pain was 58.3%. After allowance for other occupational activities, the onset of low-back pain was strongly associated with heavy lifting at work (men: relative risk (RR) 2.0, 95% confidence interval (95% CI) 1.4-2.8; women: RR 2.2, 95% CI 1.3-3.5). For the men there was also an association with digging (RR 1.6, 95% CI 1.1-2.3). Risk of low-back pain increased with height among the men but not among the women. The risks associated with heavy lifting and digging were greater for the short than for the tall men. Thus the data provide no justification for excluding tall men from heavy manual tasks, despite their greater susceptibility to back problems.