Epidemiological study to investigate potential interaction between physical and psychosocial factors at work that may increase the risk of symptoms of musculoskeletal disorder of the neck and upper limb

Objectives: To investigate potential interactions between physical and psychosocial risk factors in the workplace that may be associated with symptoms of musculoskeletal disorder of the neck and upper limb. Methods: 891 of 1514 manual handlers, delivery drivers, technicians, customer services computer operators, and general office staff reported on physical and psychosocial working conditions and symptoms of neck and upper limb disorders using a self administered questionnaire (59% return rate). Of the 869 valid questionnaire respondents, 564 workers were classified in to one of four exposure groups: high physical and high psychosocial, high physical and low psychosocial, low physical and high psychosocial, and low physical and low psychosocial. Low physical and low psychosocial was used as an internal reference group. The exposure criteria were derived from the existing epidemiological literature and models for physical and psychosocial work factors. The frequency and amplitude of lifting and the duration spent sitting while experiencing vibration were used as physical exposure criteria. Ordinal values of mental demands, job control, and social support with managers and coworkers were used as psychosocial exposure criteria. Results: In the multivariate analyses, the highest and significant increase in risk was found in the high physical and high psychosocial exposure group for symptoms of hand or wrist and upper limb disorders after adjusting for years at the job, age, and sex. A potential interaction effect was found for the symptoms of the hand or wrist and upper limb disorders but not for the neck symptoms. Conclusion: This study showed that workers highly exposed to both physical and psychosocial workplace risk factors were more likely to report symptoms of musculoskeletal disorders than workers highly exposed to one or the other. The results suggest an interaction between physical and psychosocial risk factors in the workplace that increased the risk of reporting symptoms in the upper limbs. Psychosocial risk factors at work were more important when exposure to physical risk factors at work were high than when physical exposure was low. Ergonomic intervention strategies that aim to minimise the risks of work related musculoskeletal disorders of the upper limb should not only focus on physical work factors but also psychosocial work factors.     

Psychosocial and physical risk factors associated with low back pain: a 24 year follow up among women and men in a broad range of occupations

OBJECTIVES: To investigate the relation between psychosocial and physical factors at work, as well as conditions during leisure time, and low back pain (LBP) over 24 years. METHODS: The study group consisted of 252 women and 232 men. From a previous study conducted in 1969, data on psychosocial and physical conditions and LBP were available. Data on LBP for 1971-93 were obtained retrospectively in 1993. RESULTS: The prevalence of LBP in 1969 among women and men were 34% and 24%, the cumulative incidences of LBP during 1970-92 were 38% and 43%, and the prevalences in 1993 of having had LBP during the past 12 months were 44% and 39%, respectively. Monotonous work and few or unsatisfactory social contacts outside work were risk factors for LBP in 1969 among women. LBP in 1969 and dissatisfaction with leisure time were risk factors among both sexes for LBP in 1970-92. LBP in 1969 was a risk factor for LBP in 1993 among women and dissatisfaction with leisure time a risk factor among men. Interactions between few or unsatisfactory social contacts outside work, as well as dissatisfaction with leisure time, and several factors related to work were found to increase the risk of LBP among both sexes during the studied periods. CONCLUSIONS: Conditions in leisure time exert a long term influence on LBP. In this study factors related to work had a long term effect only in interaction with leisure time factors.

 

     

Do work-related physical factors predict neck and upper limb symptoms in office workers?

Objectives: The objective of this study was to examine the influence of physical exposure at work on neck and upper limb symptoms in office workers. Methods: Data were used from a prospective cohort study with a follow-up period of 3 years. Independent variables were physical exposure at work, observed and self-reported. Outcome measures were neck–shoulder symptoms and elbow–wrist–hand symptoms. Data were analyzed with the generalized estimating equation (GEE) method, with adjustment for age, gender, psychosocial work characteristics and the outcome at baseline. Results: Neck rotation was associated with neck–shoulder symptoms in the analyses with observed data (OR: 1.57; CI: 0.99–2.50) as well as those with self-reported data (OR: 1.43; CI: 1.02–2.01). Neck extension was also statistically significantly associated with neck–shoulder symptoms (OR: 2.42; CI: 1.22–4.80), but only self-reported data were available. Neck flexion, self-reported wrist pronation, self-reported arm elevation and self-reported duration of computer work, were not associated with symptoms. An indication was found of an adverse effect on neck–shoulder symptoms of long working days and on elbow–wrist–hand symptoms of self-reported wrist flexion and full-time work or longer compared to part-time work. Conclusions: Only a limited number of work-related physical factors were related to neck and upper limb symptoms in office workers. Only neck rotation and self-reported neck extension were identified as risk factors for neck-shoulder symptoms.     

Musculoskeletal disorders of the neck and shoulders in female sewing machine operators: prevalence, incidence, and prognosis

OBJECTIVES—To assess the occurrence and persistence of two restrictively defined neck-shoulder disorders among sewing machine operators. To assess factors associated with the development of neck-shoulder disorder and prognostic factors for remaining a case, when disorders were already present.
METHODS—In an initial group of 243 sewing machine operators, 178 were followed up for 2 years. At baseline and at 1 and 2 years follow up the participants underwent a clinical examination of the neck and arms and filled in a questionnaire about current musculoskeletal complaints. Clinical criteria for two main neck-shoulder disorders were defined: rotator cuff tendinitis and myofascial pain syndrome. A baseline control group consisted of 357 women with varied non-repetitive work.
RESULTS—At baseline the overall prevalence of myofascial pain syndrome and rotator cuff tendinitis was 15.2% and 5.8% among sewing machine operators compared with 9.0% and 2.2%, respectively, among controls. The presence of the disorders was strongly associated with a self perception of poor general health. Although myofascial pain syndrome showed a U shaped association with years as a sewing machine operator, rotator cuff tendinitis was absent among the newest recruits and present among 15% of the women with more than 20 years as a sewing machine operator. Besides years as a sewing machine operator, the risk of having a neck-shoulder disorder at baseline was significantly associated with high stress (prevalence ratio (PR)=2.54; 95% confidence interval (95% CI) 1.28 to 5.05) when adjusted for age, body mass index, smoking, living alone with children, job strain, and social support from colleagues and supervisors. Only one of 13 participants with rotator cuff tendinitis at baseline recovered during follow up. Myofascial pain syndrome showed a much more fluctuating tendency. Low social support (RR 3.72; 95% CI 1.22 to 11.30) and smoking (RR 3.93; 95% CI 1.33 to 11.58) were associated with the development of neck-shoulder disorders, which was also associated with neck-shoulder pain score and living alone with children.
CONCLUSION—Rotator cuff tendinitis showed a higher degree of persistence than myofascial pain syndrome. Both disorders highly influenced the perception of general health. Women who lived alone with children, were smokers, or experienced low support from colleagues and supervisors had a higher risk of contracting a neck-shoulder disorder.


Keywords: rotator cuff syndrome; myofascial pain syndrome; follow up study; prognostic risk factors     

The relative contribution of work exposure, leisure time exposure, and individual characteristics in the onset of arm–wrist–hand and neck–shoulder symptoms among office workers

Purpose

To identify the risk factors for the onset of arm–wrist–hand and neck–shoulder symptoms among office workers and to estimate the relative contribution of these risk factors by calculating Population Attributable Fractions (PAFs).

Methods

A prospective cohort study was conducted among 1951 office workers with a follow-up duration of 2?years. Data on self-reported risk factors were collected at baseline and after 1?year of follow-up. Every 3?months, the occurrence of upper extremity symptoms was assessed using questionnaires. PAFs for individual risk factors were estimated based on Rate ratios (RRs) obtained from Poisson regression using Generalized Estimation Equations.

Results

Previous disabling symptoms were identified as the most important risk factor for the onset of arm–wrist–hand and neck–shoulder symptoms. Modifiable risk factors for arm–wrist–hand symptoms with relatively large PAFs were: at least 4?h per day of self-reported computer use at work, high level of overcommitment, and low task variation and for neck-shoulder symptoms: supporting the arms during keyboard use and at least 4?h per day of self-reported mouse use at work. Compared to having 0 or 1 risk factor, the RR for arm–wrist–hand symptoms increased to 6.2 (95% CI 3.7–10.5) for having 5–7 potentially modifiable risk factors and for neck–shoulder symptoms to 3.0 (95% CI 2.1–4.4) for having 4 or 5 potentially modifiable risk factors.

Conclusion

Preventive interventions at the population level should be aimed at changing modifiable risk factors with large PAFs. At the individual level, preventive interventions should be aimed at changing multiple modifiable risk factors simultaneously.     

中国医疗行业工作相关肌肉骨骼疾患发生模式及其影响因素分析

目的  调查中国医疗行业工作相关肌肉骨骼疾患(work-related musculoskeletal disorders, WMSDs)发生情况,探究不同岗位不良工效学职业危害因素及WMSDs发生模式。方法  通过《北欧肌肉骨骼疾患问卷(修改版)》电子问卷系统对中国6 854名医疗行业从业人员进行横断面调查。根据美国国家职业安全卫生研究所(National Institute for Occupational Safety and Health, NIOSH)判定WMSDs方法进行发生结果统计分析。应用潜类别分析(latent class analysis, LCA)对主要工种WMSDs多部位发生模式进行分析,利用logistic回归分析法确定不良工效学因素。结果  调查样本中,不计部位的总体WMSDs发生率为56.1%。其中,医生为54.15%、护士为58.66%、护工为51.04%、技师为54.05%、药师为48.48%。根据LCA分类结果,医生与护士WMSDs发生模式主要有颈肩型和躯干型;技师主要为颈肩型;药师为颈肩型;护工主要为颈肩型和轻微疼痛型。多因素logistic回归分析结果显示,颈肩型医生发生危险主要来自手腕长期弯曲(OR=1.383, P=0.036),频繁坐位工作(OR=2.110, P=0.020),工作姿势经常不舒服(OR=2.023, P=0.001);躯干型医生发生危险主要有腿部姿势受限(OR=1.413, P=0.044),频繁不舒适工作姿势(OR=4.402, P＜0.001);颈肩型护士发生危险主要来自颈部大幅度前倾(OR=2.218, P=0.024),长时间频繁坐位工作(OR=1.533, P=0.006);躯干型护士发生危险有长时间频繁坐位工作(OR=1.883, P < 0.001),频繁不舒适工作姿势(OR=2.137, P < 0.001)。结论  中国医疗行业WMSDs发生率同世界主流国家地区相比处于中等水平。但行业总体不良工效学危害水平较高,不良作业姿势普遍存在。其中颈部、肩部、上背部、下背部的工效学负荷水平较高,主要与颈部工作中长时间保持不变、长时间低头、颈部大幅度前倾、手腕长期弯曲、长时间保持转身、腿部空间受限、长时间坐姿、作业姿势不舒服等职业因素有关。应通过加强宣教培训、增加辅助助力设施、改善工作组织模式等方式,降低肌肉骨骼损伤危险。     

Disorders of the neck and upper limbs in women in the fish processing industry.

OBJECTIVE--The aim was to study the association between personal factors and physical and psychosocial work environment factors and disorders of the neck or upper limbs among women in the fish processing industry. METHODS--A cross sectional study was performed on 206 women in the fish processing industry and 208 control women. Several physical and psychosocial work environment factors were evaluated. Subjective complaints about the neck or upper limbs were assessed by questionnaire and by a clinical examination. RESULTS--The study showed a high prevalence (35%) of diagnoses in the neck or shoulders of the exposed women. All prevalence odds ratios (POR's) were substantially higher in young women. There was a pronounced dose-response relation between disorders of the neck or shoulders and duration of employment for women < 45 years old. When studying 322 former workers, the proportion who claimed musculoskeletal complaints as the reason for leaving was highest among the older women. Muscular tension, stress or worry, work strain, and the largest fraction of the work time spent with highly repetitive work tasks were clearly associated with disorders of the neck or shoulders. The measurements of the wrist movements also showed that the work was performed almost without any pauses and that the median flexion and extension velocity was high (41 degree/s). The results of observation showed good agreement with the measurements of wrist motion. CONCLUSION--Work in the fish processing industry is a risk factor for disorders of the neck and upper limbs. Due to the homogenity of the physical work load in the exposed group, we could not show any associations between the objective measurements and disorders. In cross sectional studies the risk may be underestimated due to a healthy worker effect.     

Psychosocial conditions on and off the job and psychological ill health: depressive symptoms,impaired psychological wellbeing,heavy consumption of alcohol

Background: Psychiatric epidemiology has revealed a number of associations between gender, socioeconomic status, and psychiatric disorders.

Aims: To examine psychosocial conditions on and off the job in relation to psychological ill health.

Methods: Longitudinal design with 24 year follow up of employed persons (190 women, 177 men). Interview and questionnaire data on work and leisure conditions were collected in 1969 and 1993. Risk analyses were performed in relation to three outcomes in 1993: depression within the preceding 12 months, impaired psychological wellbeing, and heavy alcohol use.

Results: Thirteen per cent of the women and 11% of the men showed symptoms of depression, 21% and 22% had impaired psychological wellbeing, and 7% and 15% respectively were heavy alcohol users. Dissatisfaction with the quality (women) or quantity (men) of social contacts 24 years earlier was a significant risk factor for depression. Dissatisfaction with the quality of social contacts was also associated with impaired psychological wellbeing (among women), and dissatisfaction with leisure time activities was associated with heavy alcohol use (among men). Frequent overtime work 24 years earlier was associated with heavy alcohol use among women. Cross sectional analyses also showed associations between psychological ill health and some work related factors (mentally demanding work and lack of job pride).

Conclusions: Perceived inadequacies in social contacts, and practical obstacles to social relationships are viewed as risk factors for depression. In this longitudinal study, work related factors, including mental demands and time pressure, do not appear sufficiently associated with psychological ill health.

     

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.     

Physical workload and risk of early retirement: prospective population-based study among middle-aged men

Early retirement produces a heavy economic burden in many western societies. There is a need to identify single risk factors for early retirement and to find methods for preventing it. To estimate the effect of heavy physical work on early retiring, a cohort of 1755 men aged 42 to 65 years from eastern Finland was followed up from 1984 to 2000. Self-estimated physical workload was assessed at baseline. The inclusive pension records were obtained from national pension institutions. Logistic regression modeling was used to estimate the effect of physical workload and single physical risk factors on the risk of disability pension and nonillness-based pension. Risks were estimated for both disease-specific and all disability pensions. The interaction of physical fitness and physical workload and the resulting effects on risk were also estimated. During the follow-up, 861 (49.1%) men retired on a disability pension and 331 men (18.9%) retired on a nonillness-based early pension. Only 273 (15.6%) men reached the age for getting the normal old-age pension without having had any other early pension After adjustment for age, body mass index, alcohol consumption, smoking, maximal oxygen uptake, education and corresponding illness at baseline, heavy physical work was found to be associated with an increased risk of being retired on a disability pension due to musculoskeletal disorders (odds ratio (OR) 2.21, 95% confidence interval 1.36 to 3.61) but not due to cardiovascular or mental diseases. The association was stronger if cardiorespiratory fitness was poor. Lifting, static muscular loading and uncomfortable work positions increased the risk of early retirement especially due to musculoskeletal disorders. Loading of the upper extremity alone or with the neck and shoulder region seems to be an independent risk factor for early retirement. We concluded that physical workload increases the risk of retirement on a disability pension especially due to musculoskeletal disorders. In heavy physical work, the risk is increased especially among men with musculoskeletal or cardiovascular disease and poor cardiorespiratory fitness.     

Upper-limb disorders in repetitive work

OBJECTIVES: A longitudinal study was conducted to determine the predictability of personal and occupational factors with respect to the incidence of upper-limb disorders in occupations requiring repetitive work. METHODS: A sample of 598 workers in five activity sectors completed a self-administered questionnaire; the workers were examined by an occupational health physician in 1993-1994 and 3 years later. Three disorders were considered, carpal tunnel syndrome (CTS), lateral epicondylitis and wrist tendinitis. RESULTS: The results of this longitudinal study indicated that the following three sets of risk factors independently affect the incidence of upper-limb disorders: (i) biomechanical constraints, (ii) psychosocial factors, and (iii) personal factors. The combination of risk factors differed between CTS, lateral epicondylitis, and wrist tendinitis. The presence of psychosomatic problems was a strong predictor of wrist tendinitis. Social support at work was also associated with the incidence of wrist tendinitis. The presence of depressive symptoms and other upper-limb disorders predicted the first occurrence of lateral epicondylitis. Age was associated only with epicondylitis. The results were consistent with those concerning the role of forceful movements of the elbow for epicondylitis and confirmed the role of forceful movements for CTS. CONCLUSIONS: This study considered different sets of risk factors simultaneously with a longitudinal approach, in a population with a high level of occupational exposure. The results indicate that three sets of risk factors independently affect the incidence of upper-limb disorders. In addition to biomechanical constraints, psychosocial and personal factors play a role.     

Anatomic distribution of sensory symptoms in the hand and their relation to neck pain,psychosocial variables,and occupational activities

To explore whether different distributions of numbness and tingling in the hand can be usefully distinguished in epidemiologic studies of disorders such as carpal tunnel syndrome, the authors used a postal questionnaire, an interview, and a physical examination to collect information about risk factors, symptoms, and signs from a general population sample of 2,142 adults in Southampton, England, during 1998-2000. The authors distinguished six distributions of numbness and tingling and compared their associations with other clinical findings and with known risk factors for upper limb disorders. Distinctive relations were found for symptoms that involved most of the palmar surface of the first three digits but not the dorsum of the hand or the little finger. Such symptoms were more often associated with positive Phalen's and Tinel's tests and, unlike other categories of sensory disturbance, were not related to neck pain or restriction of neck movement. They also differed in showing no association with lower vitality or poorer mental health but an association with repeated wrist and finger movements at work. These findings suggest that, in the classification of numbness and tingling of the hand, it may be useful to distinguish symptoms that involve most of the sensory distribution of the median nerve but not other parts of the hand.     

Child labor and musculoskeletal disorders: the Pelotas (Brazil) epidemiological survey

OBJECTIVES: [corrected] This article describes the prevalence of musculoskeletal pain in several anatomic sites in children and teens, and investigates, while adjusting for potential confounders, the association between musculoskeletal pain and back pain and the following: age, gender, sports practice, use of computer/video games/television, school attendance, intensity of involvement in household domestic activities, care of other children, care of sick/elderly family members, work activities, and workloads. METHODS: We conducted a cross-sectional study interviewing 3,269 children aged 10-17 years in the low-income areas of Pelotas, Brazil. RESULTS: The prevalence of pain in the neck, knee, wrist or hands, and upper back exceeded 15%. Workers in manufacturing had a significantly increased risk for musculoskeletal pain (prevalence ratio [PR]=1.31) and for back pain (PR=1.69), while workers in domestic service had 17% more musculoskeletal pain and 23% more back pain than nonworkers. Awkward posture (PR=1.15) and heavy physical work (PR=1.07) were associated with musculoskeletal pain, while monotonous work (PR=1.34), awkward posture (PR=1.31), and noise (PR=1.25) were associated with back pain. CONCLUSIONS: Musculoskeletal pain is common among working children and teens. Knowledge of occupational risk factors can support actions to restructure work conditions to reduce or eliminate childhood exposure to hazardous conditions. Our results suggest that strategies to prevent musculoskeletal disorders in child workers should be developed.     

The relationship between leisure time, physical activities and musculoskeletal symptoms and disability in worker populations

Objectives: To assess the association between leisure time physical activity and musculoskeletal morbidity, as well as possible interactions with physical activity at work. Methods: A literature search was performed to collect all studies on musculoskeletal disorders in which physical activity was involved as a variable. Next, an analysis was made of questionnaire data on a group of 2,030 workers in various occupations, on self-reported physical activity in leisure time and at work, musculoskeletal symptoms (from low back, neck-shoulder and lower extremity) and sick leave due to these symptoms. A logistic regression analysis was carried out to estimate the association between musculoskeletal morbidity and four physical-activity indices (participation in sports and sedentary activities, active life style, sedentary life style), adjusted for age, gender, education and work load. Interaction of leisure activities with age and work load was tested too. Results: Available literature data (39 studies) showed inconsistent results. Most studies did not show any effects. Some studies indicated favourable effects of physical activity, both on low back and neck pain. Participation in some vigorous sports seemed associated with unfavourable effects. The empirical data showed no association between participation in sports and/or other physical activities in leisure time and musculoskeletal symptoms. Sedentary activity in leisure time was associated with higher prevalence rates of low back symptoms and sick leave due to low back symptoms. Conclusions: Stimulation of leisure time physical activity may constitute one of the means of reducing musculoskeletal morbidity in the working population, in particular in sedentary workers. Received: 4 October 1999 / Accepted: 25 April 2000     

Work-related risk factors for the incidence and recurrence of shoulder and neck complaints among nursing-home and elderly-care workers

OBJECTIVES: This study assessed the differences and similarities in the incidence and recurrence of shoulder and neck complaints with respect to work-related physical, psychosocial, and personal risk factors. METHODS: A prospective cohort study was carried out among 769 workers of nursing homes and homes for the elderly. At baseline, a questionnaire was used to collect data on personal characteristics, physical workload, psychosocial workload, and the presence of shoulder and neck complaints. After 1 and 2 years, follow-up data were collected on shoulder and neck complaints. Generalized estimation equations were used for analyzing risk factors for the participants with at least one follow-up measurement available (N=556, 72%). RESULTS: In the multivariate model, adjusted for age and gender, obesity [odds ratio (OR) 2.12, 95% confidence interval (95%CI) 1.23-3.65] was related to the incidence of shoulder complaints. The incidence of neck complaints was increased for obesity (OR 1.81, 95% CI 1.07-3.05), work in awkward postures (OR 1.76, 95% CI 1.11-2.78), and poor or fair general health (OR 1.53, 95% CI 1.02-2.31). The recurrence of both shoulder and neck complaints was associated with chronic complaints at baseline (shoulder: OR 1.91, 95% 1.36-2.67; neck: OR 1.71, 95% 1.14-2.55) but not with work-related risk factors. CONCLUSIONS: The results suggest that there are differences in risk factors for the incidence and recurrence of shoulder and neck complaints.     

Work related and individual predictors for incident neck pain among office employees working with video display units

Aims: To investigate work related and individual factors as predictors for incident neck pain among office employees working with video display units (VDUs).

Methods: Employees in three administrative units of a medium sized city in Finland (n = 515) received mailed questionnaires in the baseline survey in 1998 and in the follow up survey in 1999. Response rate for the baseline was 81% (n = 416); respondents who reported neck pain for less than eight days during the preceding 12 months were included into the study cohort as healthy subjects (n = 232). The follow up questionnaire 12 months later was completed by 78% (n = 180). Incident neck cases were those reporting neck pain for at least eight days during the preceding 12 months.

Results: The annual incidence of neck pain was 34.4% (95% CI 25.5 to 41.3). Poor physical work environment and poor placement of the keyboard increased the risk of neck pain. Among the individual factors, female sex was a strong predictor. Smoking showed a tendency for an increased risk of neck pain. There was an interaction between mental stress and physical exercise, those with higher mental stress and less physical exercise having especially high risk.

Conclusion: In the prevention of neck disorders in office work with a high frequency of VDU tasks, attention should be given to the work environment in general and to the more specific aspects of VDU workstation layout. Physical exercise may prevent neck disorders among sedentary employees.

     

The Prevalence of Musculoskeletal Complaints among Women in Tijuana,Mexico: Sociodemographic and Occupational Risk Factors

Abstract

The authors interviewed an age- and occupation-stratified sample of 466 women, aged 18–40, from 12 Tijuana neighborhoods, about sociodemographic characteristics, work and reproductive history, and musculoskeletal complaints. A total of 29.8% reported experiencing aches or pain in the low back, 38.3% in the upper back, 26.4% in the neck/shoulders, 18.2% in the hand/wrist, and 28.3% in the legs in the preceding year. Both sociodemographic and occupational factors were associated with these complaints. Very low educational attainment, having substandard housing, being the head of household, and being a migrant were each associated with an increased prevalence of one or more musculoskeletal complaints. In general, working outside the home increased the risk of musculoskeletal complaints. Compared with women who had not worked in the preceding 30-month period, those working in the maquiladora had 40–90% higher risks of upper back, neck/shoulder, and hand/wrist pain. Compared with women working outside the maquiladora, maquiladora women workers had 20% higher risks of low back, upper back, and neck/shoulder complaints. More detailed studies of the incidences of musculoskeletal disorders and of specific etiologic risk factors within the maquiladora industry are warranted. Future studies should concurrently evaluate sociodemographic risk factors.     

Differences in physical workload,psychosocial factors and musculoskeletal disorders between two groups of female hospital cleaners with two diverse organizational models

Objectives To clarify if differences in the physical workload, the psychosocial factors and in musculoskeletal disorders can be attributed to work organizational factors. Methods The physical workload (muscular activity of m. trapezius, positions and movements of the head, upper arms and wrists and heart rate) was assessed in 24 female hospital cleaners working in a traditional work organization (TO) and in 22 working in an extended one (i.e. with an enlarged work content and more responsibilities; EO). The psychosocial work environment was assessed as job demand, decision latitude and social support in 135 (TO) and 111 (EO) cleaners, and disorders of the neck and upper extremity by a physical examination. Results The EO group was associated with lower physical workload, in terms of heart rate ratio (23 vs 32; P < 0.001), head and upper arm positions and movements (right upper arm, 50th percentile, 35°/s vs 71°/s; P < 0.001) and wrist movements (20°/s vs 27°/s; P = 0.001), than the TO group. The EO group reported higher decision latitude and lower work demand than the TO one, while we found no difference in social support. The prevalence of complaints and diagnoses in neck/shoulders were lower in the EO group (diagnoses 35% vs 48%; P = 0.04). Moreover, the prevalence of subjects with at least ten physical finding in elbows/hands was lower in the EO group (10 vs 29; P < 0.001). Conclusion Hospital cleaners have a high prevalence of neck and upper limb disorders and a high physical workload. Comparing two groups of cleaners, with differences in the way of organizing the work, lower physical workload, more beneficial psychosocial factors and a better musculoskeletal health was found in the group with an extended organization. Hence, the differences found can be attributed to the organizational factors.     

The prevalence of musculoskeletal complaints among women in Tijuana, Mexico: sociodemographic and occupational risk factors

The authors interviewed an age- and occupation-stratified sample of 466 women, aged 18-40, from 12 Tijuana neighborhoods, about sociodemographic characteristics, work and reproductive history, and musculoskeletal complaints. A total of 29.8% reported experiencing aches or pain in the low back, 38.3% in the upper back, 26.4% in the neck/shoulders, 18.2% in the hand/wrist, and 28.3% in the legs in the preceding year. Both sociodemographic and occupational factors were associated with these complaints. Very low educational attainment, having substandard housing, being the head of household, and being a migrant were each associated with an increased prevalence of one or more musculoskeletal complaints. In general, working outside the home increased the risk of musculoskeletal complaints. Compared with women who had not worked in the preceding 30-month period, those working in the maquiladora had 40-90% higher risks of upper back, neck/shoulder, and hand/wrist pain. Compared with women working outside the maquiladora, maquiladora women workers had 20% higher risks of low back, upper back, and neck/shoulder complaints. More detailed studies of the incidences of musculoskeletal disorders and of specific etiologic risk factors within the maquiladora industry are warranted. Future studies should concurrently evaluate sociodemographic risk factors.