among construction laborers represented in the New. York State by the Laborers' International Union of. North America (LIUNA). There is substantial evidence.
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SELF-REPORTED MUSCULOSRELETAL SYMPTOMS AMONG MASON TENDERS AND PERCEIVED JOB-RELATED CRARACTERISTICS David Goldsheyder, Shira Schecter-Weiner, Margareta Nordin, Rudi Hiebert Occupational & Industrial Orthopaedic Center (OIOC), Hospital for Joint Diseases New York, NY A musculoskeletal symptom survey was conducted among mason tenders in New York City. The return rate of the survey was 70.2%. The outcome revealed that 65% of the mason tenders experienced low back pain during the year prior to the survey, 35% of them were absent from work, and 45% visited a physician due to the symptoms. The job-related characteristics perceived by the mason tenders as the most problematic included bending or twisting the back working in the same position for long periods of time, working overhead or away from the body, and working near or at physical limits. The study results were incorporated in the design and implementation of low back pain prevention program that trained the union trade instructors in ergonomic hazard recognition and problem solving, and targeted the mason tenders. INTRODUCTION The study describes the first phase of a research project aimed at primary prevention of low back pain among construction laborers represented in the New York State by the Laborers’ International Union of North America (LIUNA). There is substantial evidence that low back pain has a large impact in industrialized countries. About 2% of the workforce in the U.S. is compensated each year as the result of back pain. It is responsible for about 12.5% of all sick days in the UK, and reportedly causes 13% to 19% of all sickness absence days in Sweden (Andersson, 1999). For years, constrnction has been known as the industry with the greatest risk for low back injuries and disorders. Construction trades and construction laborers had the highest prevalence of low back pain with 32.7% and 38.6% respectively among working trades and professions in Holland (Hildebrandt, 1995). In Germany construction workers were identified as at an increased risk for low back pain, with an odds ratio of 2.3 for those working in the trade longer than 10 years (Stumer et al., 1997). Almost 72% of all sick-leave days of more than 4 weeks among Swedish unionized construction workers representing different trades were attributable to musculoskeletal disorders, with 54% prevalence for low back pain (Holmstrom et al., 1992). The estimates of low back pain among different categories of workers in the U.S. revealed construction laborers at the highest risk followed by nursing aides (Guo et al., 1995). One year prevalence of low back symptoms among construction workers from 13 different trades in Iowa ranged between 60% and 87% (Cook et al., 1996). In the study, 71% of construction laborers experienced low back symptoms one year prior to the survey. Despite considerable efforts to addressthe problem, low back pain remains the most prevalent, costly, and the most disabling work-related musculoskeletal disorder. Accounting for about 20% of
all injuries and illnesses in the workplace, it costs the U.S. nearly $50 billion per year (NIOSH, 1991). The substantial number of workers employed in construction and their high risk for lower back injuries underscored the need for an effective injury prevention strategy to addressthe problem. The goal of such a strategy should be focused on the identification of factors causing disabling back injuries and the development of programs aimed at the prevention of these situations from occurring in the first place (Frymoyer, 1992). Construction laborers work in different kinds of building and construction performing a variety of physically demanding tasks. The major types of their work include building demolition, mortar mixing, supply of materials, pallctizing, hoisting, moving bricks, blocks, and structural elements, erecting or dismantling scaffolds, construction, repair and maintenance of highways, bridges, and other large strnctures, cement and concrete works, and asbestos and hazardous waste remediation. The lower back is the most frequently injured body part among construction laborers and is the most frequent source of pain complaint, lost work time and early retirement, Upon approval from the Advisory Board, the present project was focused on a specific LRJNA trade represented in New York City by mason tenders, demolition workers, and general laborers (referred to here as mason tenders). The nature of their work involves frequent manual lifting, carrying, moving, pushing or pulling of heavy construction materials, equipment and tools, prolonged awkward postures, a fast paced job, and exposure to extreme environmental conditions, Therefore, mason tenders are believed to be at increasedrisk for low back pain. The overall goal of the project was to develop and implement a program by which local labor organizations working together with ergonomics experts and local
community resources could reduce the morbidity associated with work-related musculoskeletal disorders of the back and low back pain. The first phase of the project included the description of the demographic, temporal and musculoskeletal injury characteristics of the mason tenders and the identification job-related characteristics they perceived as contributing to their symptoms. METHOD Musculoskeletal symptoms survey. Surveys have been frequently used in ergonomics field studies as useful tools for assessingthe presence of symptoms of work-related musculoskelctal disorders, for characterizing job-related factors associated with these disorders, and for assessing symptoms and outcomes before and aher an ergonomic intervention (Lemaster et. al., 1997). Prior to conducting the survey a number of questionnaires were reviewed to avoid mistakes and build upon the success of others. Due to the similar goals, target groups and problem under investigation as well as the appropriate content, relative simplicity, and limited time required for its completion, the Iowa constmction questionnaire was chosen as a survey tool for the project (Cook et al., 1996). The original questionnaire contained four sections: demographics, musculoskeletal symptoms, job-related characteristics and comments. Some modifications have been made within the content of the original instrument. Two questions were added to the first section that initially included eight demographic questions asking the respondents to indicate their specialty within the trade, years in the trade, yearly working time, having completed apprentice training, hand dominance, gender, age, height, and weight. The two added questions asked the respondents about the number of contractors they worked for in the year prior to the survey and about their native language. The rational behind the first question was that employers might have more incentives to invest in safety and health if they keep workers for longer time, On the other hand, if the workers changejobs frequently, the employer may be reluctant to invest. The purpose of the second question stemmed from the fact that the workforce in New York City is very diverse and multilingual. This circumstance causes communication problems that might jeopardize the safety and health of workers especially if they work in teams. Modifications in the musculoskeletal section included enhanced pictorial content, arrows drawn from names of nine body parts to the corresponding regions imposed on the figure and adoption of a user-friendly layout that guided the respondents to answer ‘Yes’ or ‘No’ to the question: “During the last 12 months have you had an ache, pain
or discomfort in.. .” with the nine body regions listed. If the respondent indicated that musculoskeletal symptoms had occurred, he (she) was then asked to answer ‘Yes’ or ‘No’ to two additional questions: “During the last 12 months have you been absent from work due to this condition?” and “During the last 12 months have you seena physician for this condition?” One question added to the section asked the respondents to indicate if they experienced the musculoskeletal symptoms in any of the nine body regions during the seven days prior to the survey. The question corresponded to the point prevalence, a statistical characteristic used for various purposes. The job-related characteristics section listed physically stressful work-related activities and job factors that the respondents might perceive contributing to their symptoms, Modifications in the section included clarification of some questions, addressing ambiguities, and elimination of the last question. Before completing the section respondents were instructed: “On the scale from 0 to 10, please rate how difficult is each of the following activities you may perform on the job by circling the corresponding, number.” Scores of (O-l) were equivalent to ‘Not difficult at all’, whereas scores of (S-10) were equivalent to “Extremely difficult”. Scoresbetween (2-7) indicated that the activities were of a ‘Minimal to Moderate’ difficulty. Modifications in the comments section included addition of two questions: one asking the respondentsabout any interest they might have to learn more about job safety and health, and ways of acquiring this information through either classroom training, on-site training, video, Internet or brochure. The last question asked the respondents for comments or suggestions regarding issues of job safety health, and musculoskeletal injuries in their trade. All the sections were laid out on a regular size page, the first two sections on one side and two remaining sections on the other. Five televisions were offered by the Mason Tenders Local Union (MTLU) as lottery prizes to stimulate worker participation in the survey. To underscore the fact, a statement “If you have tilled & QIJBSTIONS, you are eligible for the Prize!” was imposed on the top of the first side and on the bottom of the second side of the questionnaire. Only those who fully completed the questionnaire, were included in the lottery. Questionnaire administration. The survey was distributed during a mason tenders’ union membership meeting, rather than via postal mailing. This approach was chosen because of reports that suggest mailed surveys result in low rates of return. The rationale was that the return rate could be increased through direct interaction with the mason tenders,
including the possibility to describe the project and its benefits, as well as to encourage participation via the high chances to win a lottery prize. According to the MTLU, about 520-580 mason tenders regularly attended the membership meetings. Based on this fact, six hundred survey envelopes were prepared for the administration and numerically coded. Each envelope contained the questionnaire and two letters, one signed by the MTLU leadership and another signed by the research team. The purpose of the letters was to encourage the active participation of mason tenders in the survey. The MTLU letter also contained information about the lottery prize and eligibility criteria for inclusion in the lottery. The enclosed questionnaire had the same code as the corresponding envelope. Two members of the research team and two representatives from the MTLU handled the survey administration. Each survey administrator kept a log containing 150 codes (from # 1 to # 150; from # 151 to # 300; from # 301 to # 450; and from # 451 to # 600). After confirming the meeting attendanceby scanning their membership cards, the mason tenders were then directed to the table with the survey administrators. Their membership (‘book’) numbers were written down on the log against the unique codes and they received a self-addressed,postage paid and coded survey envelope. The rational behind this approach was that those mason tender who did not return the questionnaire in two weeks (the allocated time for survey completion) could be identified through the unique code and the reminder letter and the questionnaire with the previously assigned code could be mailed to them again. The mason tenders had an opportunity to fdl out the questionnaire on the ‘spot’ or take it home to complete and mail it back. The questionnaire administration was voluntary in nature, fully anonymous (no names were used, mentioned or released) and the mason tenders completed the survey without assistanceor prompting (NIOSH, 1997).
average 42.6 (S.D., 10.9) weeks a year. The distribution of the mason tenders by years in the trade is presentedin the Figure 1.
I-10
11-M
21-30
31.40
41.50
Years in trade
Fig 1. Distributionby yearsemployedin the trade. A very small percent of the respondents (11.2%) had some apprentice training, and of those, only 14% indicated that the training was sufficient to prepare them for a job in the trade. The respondents reported that they worked for 3.8 (S.D., 4.8) contractors in the year prior to the survey. The majority of the respondents were males (85%). Their average age was 39.9 (SD., 9.2) years, average height and weight was 5.7 feet (SD., 0.42) and 193.3 lbs. (SD., 32.9) respectively. The distribution of the mason tenders by age group is presented in Figure 2. 35 30 25 20 15
RESULTS The musculoskeletal survey was administered to 444 mason tenders. The majority filled out the questionnaires on the ‘spot’. Three hundred twelve questionnaires were returned resulting in a 70.2% response rate. Eleven poorly completed questionnaires were excluded from the analyses. Among the respondents 44% worked as mason tenders, 14% were demolition workers and 69% worked as general laborers. Some respondents indicated that they worked in more than one job category: mason tenders also worked as demolition workers or as general laborers. The respondents had an average of 12.5 (S.D., 8.4) years of experience in the trade and worked an
Fig 2. Distribution by agegroup. Among the respondents, 53.0% were right-handed and 8.0% were left-handed. For the majority (78.3%), English was the native language, 4.7% of them spoke Spanish, and 17.0% spoke Polish, Italian, or Dutch. About 82% of the mason tenders reported as least one musculoskeletal symptom during the year prior to the survey. Low back pain (ache, discomfort) was the most
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prevalent musculoskeletal symptoms with the one-year and point prevalence of 65% and 33% respectively. Due to the symptoms, 12 % of the respondents missed days on the job and 18% visited a health care provider seeking treatment. Shoulder pain was the second most frequently reported musculoskeletal symptom with oneyear and point prevalence of 42% and 21% respectively. Due to the symptoms, 5% of the mason tenders missed days on the job and 10% visited a physician. The hip (thighs) were the least frequently reported body parts with one-year and point prevalence of 18% and 11% respectively. The prevalence of self-reported musculoskeletal symptoms by body part is summarized in Table 1.
I
pushing, awkward postures, high work pace, and exposure to various environmental stressors characterize the job. These results helped to illuminate the magnitude of the problem, identify trade-specific musculoskeletal injury and job-related characteristics and develop feasible ergonomics-based intervention strategies. The information gathered also helped to facilitate the development of a low back pain prevention program that was based on the identification of ergonomic risk factors and problem solving skills to identify potential solutions. The model program was implemented for training of the union trade instructors and primarily targeted the mason tenders. ACKNOWLEGMENTS
Body
part
This research was supported by the grant horn the New York Chapter of the Arthritis Foundation and the New York State Laborers’ Health & Safety Test Fund. REFERENCES
Tablel.Prevalence of musculoskeletal symptoms by bodypart The mason tenders reported that bending or twisting the back, working in the same position for long periods of time, working overhead or away from the body, and working near or at physical limits were perceived as the most stressful work-related activities and characteristics that contributed to their musculoskeletal symptoms. The majority of the mason tenders reported that they were interested to learn more about work safety, health, and musculoskeletal disorders in the trade. They preferred classroom training as the most appropriate venue for acquiring knowledge. Safety training, learning proper lifting techniques, specific exercises, use of lifting equipment, better tools and personal protection were the issues most frequently mentioned by the mason tenders. DISCUSSION The outcome of the survey revealed that a substantial number of mason tenders experienced work-related musculoskeletal symptoms. Low back pain was the most frequently reported injury that resulted in both high work absenteeism and health care utilization. The results of the study are comparable with the results of other studies conducted earlier in different construction trades where heavy manual lifting, frequent carrying, pulling or
Andersson,G.B.J. (1999).Epidemiologicalfeaturesof chronic low-backpain. The Lsnoet 354(9178):581-585. Cook, T.M., Rosecrance,J.C., Zimmerman,CL. (1996).The University of Iowa ConstmctionSurvey.The Centerto Protect Workers’ Rights. (RBl-96). Washington,D.C. Frymoyer, J.W. (1992) Predicting disability from low back pain. Clin. OrthopaedicsandRelatedResearch,279: 101-109. Guo, How-Ran,, Tanska, S., Cameron,L.L., et al., (1995). Back pain among workers in the United States: national estimatesand workers at high risk. American Journal of IndustrialMedicine.28591-602. Hildebrandt V.H. (1995). Back pain hi the working populations:prevalenceratesin Dutch tradesand professions. Ergonomics,(38) 6: 1283-1298. Holmstrom E.B., Lindell, J. et sl (1992).Low back andneck shoulderpain in constructionworkers: occupationalworkload and psychologicalrisk factors. Part 1: Relationship to low backpain. Spine(17) 6: 663-671. Ksrmaus,W., TousssincR., et al., (1997).Constructionwork and low back disorder.Prelimhxuy fhulings of the Hamburg constructionstudy. Spine,22 (21): 2558-2563. Lemasters,G. K. & Atterbmy, M. R. (1996).The designand evaluationof musculoskeletaland work history questionnaire. In: Bhattacharya,A. andMcGlothlin, ID. (Bd.), Occupational Ergonomics.Marcel Dekker, Inc. New York. NIOSH, 1991. Work Practices Guide for Msnual Lifting. TechnicalReport Drsft. NIOSH U.S. Depsrtmentof Health andHuman Services.Cincinnati,OH. NIOSH, 1997. Elements of ergonomic programs. (DHHS, NIOSH Pub. No. 97-117). U.S. Depatlmcnt of Health and Human Services,Cincinnati,OH. Stunner, T., Luesseuhoop,S., et al., (1997). Coustruction work and low back disorder. F?elimiuary findings of the Hamburgconstructionstudy.Spine,22 (21): 2558-2563.
