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Frequent Exertion and Frequent Standing at Work, by Industry and Occupation Group — United States, 2015


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Taylor M. Shockey, MPH1; Sara E. Luckhaupt, MD1; Matthew R. Groenewold, PhD1; Ming-Lun Lu, PhD2 (View author affiliations)

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Summary

What is already known about this topic?

Occupational ergonomic hazards are risk factors for negative health outcomes such as musculoskeletal disorders. Previous research has found that employees in the agricultural and construction sectors experience high rates of musculoskeletal disorders and other injuries because of the physical nature of the work and has also found that workers in the construction and agricultural sectors have high prevalence rates of exertion including bending, lifting, pushing, and pulling.

What is added by this report?

Analysis of data from the National Health Interview Survey to examine two ergonomic hazards among currently employed adults who work at least 20 hours per week in 20 major industry groups and 22 major occupation groups found a 41.7% prevalence of frequent exertion (repeated lifting, pushing, pulling, or bending) at work and a 66.6% prevalence of frequent standing at work. A wide range in prevalence for these ergonomic hazards was observed among the industry and occupation groups.

What are the implications for public health practice?

Large differences in prevalence of frequent exertion at work and frequent standing at work exist among the major industry and occupation groups. Identification of workers with the highest prevalences of exposure to these two ergonomic hazards can inform the targeting of interventions.

Repeated exposure to occupational ergonomic hazards, such as frequent exertion (repetitive bending or twisting) and frequent standing, can lead to injuries, most commonly musculoskeletal disorders (1). Work-related musculoskeletal disorders have been estimated to cost the United States approximately $2.6 billion in annual direct and indirect costs (2). A recent literature review provided evidence that prolonged standing at work also leads to adverse health outcomes, such as back pain, physical fatigue, and muscle pain (3). To determine which industry and occupation groups currently have the highest prevalence rates of frequent exertion at work and frequent standing at work, CDC analyzed data from the 2015 National Health Interview Survey (NHIS) Occupational Health Supplement (OHS) regarding currently employed adults in the United States. By industry, the highest prevalence of both frequent exertion and frequent standing at work was among those in the agriculture, forestry, fishing, and hunting industry group (70.9%); by occupation, the highest prevalence was among those in the construction and extraction occupation group (76.9%). Large differences among industry and occupation groups were found with regard to these ergonomic hazards, suggesting a need for targeted interventions designed to reduce workplace exposure.

NHIS is an annual, in-person, household interview survey of noninstitutionalized, U.S. civilian residents that has been continuously conducted since 1957 with the main purpose of monitoring the health of the U.S. population through assessment of a range of health topics and demographic characteristics.* The NHIS questionnaire contains a set of core questions with Household, Family, Sample Adult, and Sample Child components, which have remained relatively unchanged from 1997 through 2017. In addition, NHIS has sets of questions, known as Supplements, which vary each year depending on new public health data needs. In 2015, CDC’s National Institute for Occupational Safety and Health (NIOSH) sponsored an OHS to collect information on work-related health conditions as well as psychological and physical occupational exposures. The OHS questions were included in the Sample Adult questionnaire, which had a final, unconditional response rate of 55.2%.

To determine industry and occupation, currently employed adult respondents were asked, in reference to the job they were working at during the week before the interview, “What kind of business or industry was this?” and “What kind of work were you doing?” Open-ended responses were recorded as text and subsequently coded by the U.S. Census Bureau into 4-digit codes derived from the 2012 North American Industrial Classification System (NAICS) industry groups and 2010 Standard Occupational Classification (SOC) occupation groups. To improve reliability of the statistical estimates, the detailed 4-digit industry and occupation groups were collapsed into 2-digit industry groups and occupation groups (based on the NAICS and SOC major groups§). As part of the OHS, currently employed adults were asked two questions related to the ergonomics of their current job: “How often does your job involve repeated lifting, pushing, pulling, or bending?” and “How often does your job involve standing or walking around?” Responses to these questions were dichotomized into Often/Always and Never/Seldom/Sometimes, to indicate frequent or infrequent exertion or standing, respectively. Responses to these two ergonomics questions were also used to create one dichotomous variable capturing respondents that reported both frequent exertion at work and frequent standing at work.

Among the 36,672 adult NHIS respondents, 19,456 were currently employed and considered for analyses. After excluding 1,615 respondents who worked <20 hours per week, 187 respondents who did not provide adequate information on their hours worked in the previous week, and 190 respondents in military-specific occupations, the final analytic sample included 17,464 respondents (89.8% of the currently employed adult respondents). Sample adults who worked more than 20 hours per week were more likely to be aged <65 years, men, and hold a college degree or higher; however, there was no difference in the distribution of frequent exertion and frequent standing by number of hours worked. Unadjusted prevalence of frequent exertion at work, frequent standing at work, and both frequent exertion and frequent standing at work were calculated by the 20 major industry groups and the 22 major occupation groups. The unadjusted prevalence estimates were obtained using statistical software. All analyses were weighted, and standard errors were adjusted to account for the survey design.

Overall, 39.5% of currently employed adults who work at least 20 hours per week reported both frequent exertion and frequent standing at work (Table 1). The prevalences of frequent exertion at work or frequent standing at work, or both frequent exertion at work and frequent standing at work were highest among men, persons aged 18–29 years, Hispanics, and adults with less than a high school diploma (Table 1).

Among the 20 major industry groups, the groups with the highest prevalence of both frequent exertion and frequent standing at work were agriculture, forestry, fishing, and hunting (70.9%); construction (67.2%); and accommodation and food services (57.7%) (Table 2). These same three industry groups also had the highest prevalence rates of frequent exertion at work and frequent standing at work considered separately. The finance and insurance industry group had the lowest prevalence rates of all three exposures (Table 2). Among the 22 major occupation groups, the groups with the highest prevalence of both frequent exertion and frequent standing at work were construction and extraction (76.9%); farming, fishing, and forestry (75.5%); and building and grounds cleaning and maintenance (74.0%) (Table 3). These same three occupation groups also had the highest prevalence rates for frequent exertion at work. The food preparation and serving related occupation group (97.2%) had the highest prevalence of frequent standing at work. The computer and mathematical occupation group had the lowest prevalence rate of the combined exposures of frequent exertion and frequent standing at work (4.6%) (Table 3).

Discussion

This is the first CDC report to evaluate exposure to frequent exertion and frequent standing at work among U.S. employed adults in all industries and occupations. The prevalence of exposure to both of these ergonomic hazards was higher among agricultural and construction workers than among workers in all other industries. A previous study using the U.S. Department of Labor’s Occupational Information Network database found that of 10 detailed occupation categories evaluated with regard to self-reported bending or twisting at work, half were construction-related, which is consistent with the findings from this study (4). In addition, previous research using NHIS data that evaluated musculoskeletal disorders among agricultural workers found that low back pain was the most prevalent musculoskeletal disorder. That study also found that agricultural workers had a significantly higher prevalence of upper extremity pain compared with all other industries (5). Research has shown that agricultural and construction work are physically demanding, as these industries often require manual material handling, repetitive exertions, awkward body postures, and use of machinery that causes whole body vibration (47).

Approximately two thirds of all workers reported frequent standing at work. The industry and occupation groups that reported high prevalence rates of frequent exertion (e.g., farming, construction, and food services) also tended to report high prevalence rates of frequent standing, possibly because bending, pushing, pulling, and lifting commonly co-occur with standing. Several industry and occupation groups, such as education and protective services, reported a high prevalence of frequent standing at work with a low prevalence of frequent exertion at work compared with other industry and occupation groups.

Recent studies have emphasized health risks associated with excessive sitting during the workday (8); however, excessive standing on the job also has been linked to adverse health outcomes (9). A systematic review of peer-reviewed articles on musculoskeletal symptoms and occupational standing as the main exposure variable found that occupational standing is associated with low back pain; however, associations with lower and upper extremity symptoms were inconclusive (9). More research is needed to understand how to balance time spent sitting and standing while at work.

The findings in this report are subject to at least four limitations. First, because NHIS data are cross-sectional, it is not possible to make causal inferences. Second, because NHIS data are self-reported, they are subject to recall or social desirability bias. Third, the intermediate exposure categories (Often, Sometimes, and Seldom) rely on subjective assessment of frequency. Finally, collapsing the detailed industry and occupation groups into the major industry and occupation groups might have aggregated employees with different working conditions.

Healthy People 2020 has an objective to “reduce rate of injury and illness cases involving days away from work due to overexertion and repetitive motion,” by at least 10%. NIOSH has developed educational resources on a variety of ergonomic issues.** For example, NIOSH provides a demonstration guide on ergonomic principles including how to maintain neutral postures when working, how to select the appropriate hand tools, and how to prevent fatigue failure of the vertebrae. In addition, NIOSH offers ergonomic guidelines for manual material handling, a primer for creating a workplace ergonomic programs, and ergonomic interventions by specific industry, including agriculture and construction.†† Because ergonomic hazards are risk factors for work-related musculoskeletal disorders, continued research is necessary to develop a better understanding of these hazards and to create interventions aimed at reducing them (2,810).

Conflict of Interest

No conflicts of interest were reported.


Corresponding author: Taylor M. Shockey, tshockey@cdc.gov, 513-841-4239.

1Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, CDC; 2Division of Applied Research and Technology, National Institute for Occupational Safety and Health, CDC.


References

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TABLE 1. Weighted prevalence of frequent exertion at work, frequent standing at work, and both frequent exertion and frequent standing at work among adult U.S. workers,* by demographic characteristics — National Health Interview Survey, 2015
Characteristic Both frequent exertion and frequent standing at work Frequent exertion at work Frequent standing at work
No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI)
Sex
Men 3,985 31,887,307 44.1 (42.7–45.5) 4,235 33,946,823 47.0 (45.6–48.3) 6,149 49,783,090 68.8 (67.5–70.2)
Women 2,997 20,897,950 34.0 (32.7–35.4) 3,124 21,864,499 35.6 (34.2–37.0) 5,520 39,328,061 64.0 (62.6–65.4)
Age group (yrs)
18–29 1,682 14,707,666 49.2 (46.7–51.6) 1,738 15,307,794 51.2 (48.7–53.7) 2,593 22,663,742 75.8 (73.7–77.8)
30–44 2,414 17,548,635 39.0 (37.4–40.7) 2,538 18,448,479 41.0 (39.4–42.7) 3,964 29,256,582 65.1 (63.4–66.7)
45–64 2,603 19,130,997 35.7 (34.1–37.4) 2,769 20,480,104 38.3 (36.6–39.9) 4,517 34,073,378 63.7 (62.1–65.2)
≥65 283 1,397,959 26.3 (22.5–30.0) 314 1,574,945 29.6 (25.8–33.4) 595 3,117,450 58.6 (54.4–62.8)
Race/Ethnicity
White, non-Hispanic 4,256 33,402,064 38.4 (37.2–39.7) 4,466 35,094,556 40.4 (39.1–41.7) 7,078 56,412,145 64.9 (63.6–66.1)
Black, non-Hispanic 919 6,736,754 43.4 (40.6–46.2) 971 7,199,190 46.4 (43.6–49.2) 1,555 11,046,554 71.1 (68.6–73.6)
Other race, non-Hispanic 363 2,340,168 25.4 (21.8–29.0) 387 2,562,924 27.8 (24.1–31.4) 691 4,767,859 51.7 (47.7–55.7)
Hispanic 1,444 10,306,271 46.8 (44.4–49.2) 1,535 10,954,652 49.8 (47.4–52.2) 2,345 16,884,593 76.7 (74.7–78.7)
Education level
Less than high school diploma 910 6,425,171 59.5 (56.0–63.0) 967 6,840,231 63.4 (60.1–66.6) 1,269 9,036,138 83.7 (81.4–86.0)
High school diploma/GED 2,138 16,679,503 56.6 (54.5–58.7) 2,249 17,558,718 59.6 (57.4–61.7) 3,000 23,231,939 78.8 (77.1–80.5)
Some college 2,612 19,898,969 47.3 (45.4–49.2) 2,744 21,027,565 50.0 (48.1–51.9) 3,986 30,423,401 72.3 (70.7–73.8)
Bachelor’s degree or higher 1,303 9,513,585 18.7 (17.4–19.9) 1,379 10,116,181 19.8 (18.6–21.1) 3,384 26,079,808 51.2 (49.4–52.9)
All currently employed adults 6,982 52,785,257 39.5 (38.5–40.5) 7,359 55,811,322 41.7 (40.7–42.7) 11,669 89,111,151 66.6 (65.6–67.6)

Abbreviations: CI = confidence interval; GED = General Educational Development.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
Education level only shown for persons aged ≥25 years.

TABLE 2. Weighted prevalence of frequent exertion at work, frequent standing at work, and both frequent exertion and frequent standing at work among adult U.S. workers,* by industry group — National Health Interview Survey, 2015
Industry group Both frequent exertion and frequent standing at work Frequent exertion at work Frequent standing at work
No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI)
Agriculture, Forestry, Fishing, and Hunting 199 1,168,731 70.9 (63.2–78.5) 213 1,241,068 75.2 (68.0–82.5) 238 1,428,182 86.6 (81.2–92.0)
Construction 741 5,673,721 67.2 (63.5–70.8) 782 5,959,974 70.6 (67.0–74.2) 900 7,041,656 83.4 (80.4–86.3)
Accommodation and Food Services 703 5,272,820 57.7 (53.6–61.7) 712 5,317,174 58.2 (54.1–62.2) 1,093 8,459,753 92.5 (90.6–94.4)
Retail Trade 955 7,504,966 54.6 (51.1–58.2) 977 7,682,555 55.9 (52.4–59.4) 1,403 11,235,663 81.7 (79.3–84.1)
Arts, Entertainment, and Recreation 138 1,165,969 50.1 (41.3–59.0) 143 1,214,309 52.2 (43.8–60.6) 244 1,869,437 80.4 (74.7–86.0)
Health Care and Social Assistance 1,128 8,186,368 45.9 (43.2–48.6) 1,171 8,486,195 47.6 (44.9–50.3) 1,858 13,360,776 74.9 (72.7–77.1)
Administrative and support and Waste management and remediation services 350 2,780,964 45.7 (41.2–50.1) 374 2,955,167 48.5 (43.9–53.1) 539 4,230,331 69.4 (65.6–73.3)
Manufacturing 818 6,742,939 44.7 (41.8–47.7) 872 7,299,479 48.4 (45.4–51.4) 1,198 10,054,756 66.7 (63.7–69.6)
Other service (except Public Administration) 372 2,875,412 44.1 (39.5–48.7) 389 3,003,845 46.0 (41.6–50.5) 624 4,830,228 74.0 (69.8–78.3)
Transportation and warehousing 294 2,238,125 43.7 (38.5–49.0) 352 2,781,765 54.4 (49.3–59.5) 383 2,882,926 56.4 (51.2–61.5)
Wholesale trade 181 1,563,819 40.2 (33.3–47.2) 195 1,683,560 43.3 (36.4–50.2) 274 2,349,503 60.4 (54.3–66.6)
Utilities 54 283,706 27.7 (19.3–36.1) 56 288,971 28.2 (19.8–36.6) 96 593,375 57.9 (47.4–68.5)
Mining 60 217,846 27.0 (19.3–34.6) 63 226,742 28.1 (20.2–36.0) 88 470,569 58.3 (46.0–70.5)
Real Estate and Rental and Leasing 107 745,525 26.2 (20.2–32.2) 110 794,548 27.9 (21.7–34.2) 242 1,773,803 62.4 (55.2–69.6)
Information 84 701,050 23.7 (17.7–29.6) 96 816,293 27.5 (21.2–33.9) 157 1,305,710 44.0 (37.1–51.0)
Public administration 218 1,594,215 23.0 (19.6–26.4) 234 1,706,227 24.6 (21.1–28.1) 525 3,794,816 54.8 (50.4–59.2)
Education services 390 2,698,347 22.7 (19.9–25.5) 402 2,778,152 23.4 (20.5–26.2) 1,187 8,599,529 72.3 (69.4–75.2)
Professional, scientific, and technical services 134 1,026,452 9.8 (7.6–12.0) 153 1,159,929 11.1 (8.8–13.3) 404 3,149,955 30.1 (26.5–33.6)
Finance and Insurance 55 342,473 5.0 (3.2–6.8) 64 413,560 6.0 (3.9–8.2) 209 1,651,592 24.1 (20.3–27.9)
All currently employed adults 6,982 52,785,257 39.5 (38.5–40.5) 7,359 55,811,322 41.7 (40.7–42.7) 11,669 89,111,151 66.6 (65.6–67.6)

Abbreviation: CI = confidence interval.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
The Management of Companies and Enterprises industry group was removed from the results because the cell size was <10 and did not meet the National Center for Health Statistics’ standards of reliability.

TABLE 3. Weighted prevalence of frequent exertion at work, frequent standing at work, and both frequent exertion and frequent standing at work among adult U.S. workers,* by occupation group — National Health Interview Survey, 2015
Occupation group Both frequent exertion and frequent standing at work Frequent exertion at work Frequent standing at work
No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI) No. in sample exposed Weighted no. in population % (95% CI)
Construction and Extraction 685 4,856,232 76.9 (73.2–80.6) 718 5,077,403 80.4 (76.8–84.1) 793 5,739,639 90.9 (88.7–93.2)
Farming, Fishing, and Forestry 129 731,178 75.5 (65.3–85.8) 133 749,387 77.4 (67.3–87.4) 147 888,366 91.7 (86.9–96.6)
Building and Grounds Cleaning and Maintenance 518 3,495,764 74.0 (69.9–78.1) 532 3,605,331 76.3 (72.3–80.3) 658 4,332,921 91.7 (88.7–94.7)
Installation, Maintenance, and Repair 436 1,290,688 73.0 (68.4–77.6) 451 3,611,498 75.5 (71.0–79.9) 516 4,238,754 88.6 (85.1–92.1)
Food Preparation and Serving Related 587 4,277,608 65.7 (61.1–70.2) 591 4,304,915 66.1 (61.5–70.7) 853 6,336,456 97.2 (96.1–98.4)
Production 704 5,615,533 65.2 (61.5–69.0) 738 5,884,574 68.3 (64.7–72.0) 940 7,310,817 84.9 (82.2–87.6)
Healthcare Support 285 1,965,904 62.2 (56.2–68.1) 291 2,010,000 63.6 (57.6–69.5) 395 2,769,227 87.6 (83.5–91.7)
Transportation and Material Moving 540 4,244,701 55.2 (51.0–59.5) 642 5,187,351 67.5 (63.4–71.6) 648 5,182,206 67.4 (63.4–71.4)
Healthcare Practitioners and Technical 527 4,272,338 53.1 (49.2–57.1) 543 4,375,067 54.4 (50.3–58.5) 874 6,955,460 86.5 (84.1–88.9)
Personal Care and Service 278 2,072,693 52.2 (46.1–58.3) 290 2,135,012 53.8 (47.7–59.8) 467 3,448,249 86.8 (83.3–90.4)
Sales and Related 657 5,313,669 39.3 (35.7–42.9) 675 5,484,798 40.6 (37.0–44.2) 1,194 10,006,503 73.9 (70.9–76.8)
Protective Service 119 907,995 35.0 (28.2–41.8) 123 925,096 35.6 (28.7–42.6) 280 2,198,270 84.7 (79.5–89.8)
Education, Training, and Library 267 2,057,303 25.2 (21.5–28.9) 274 2,104,193 25.8 (22.1–29.5) 891 6,717,390 82.2 (79.2–85.3)
Office and Administrative Support 528 3,847,255 24.3 (21.8–26.8) 567 4,166,405 26.3 (23.7–28.9) 996 7,528,768 47.5 (44.8–50.2)
Arts, Design, Entertainment, Sports and Media 74 579,465 22.8 (16.9–28.7) 80 631,237 24.8 (18.9–30.8) 171 1,145,550 45.1 (38.3–51.8)
Management 418 3,258,402 22.5 (19.9–25.1) 444 3,441,037 23.7 (21.1–26.4) 965 7,543,484 52.0 (49.0–55.0)
Community and Social Services 52 423,039 15.7 (10.0–21.5) 53 444,643 16.5 (10.7–22.4) 217 1,448,680 53.9 (47.1–60.7)
Life, Physical, and Social Science 31 176,272 12.1 (6.1–18.0) 34 220,958 15.1 (8.3–21.9) 107 734,098 50.2 (40.9–59.5)
Architecture and Engineering 35 337,561 10.2 (6.1–14.3) 39 366,910 11.1 (6.9–15.3) 144 1,318,074 39.8 (33.4–46.3)
Business and Financial Operations 76 594,080 7.9 (5.7–10.1) 89 696,504 9.2 (6.9–11.6) 242 1,967,945 26.1 (22.5–29.7)
Computer and Mathematical 29 232,386 4.6 (2.6–6.6) 41 336,596 6.7 (4.1–9.2) 116 949,751 18.8 (14.8–22.8)
Legal 7 32,566 § 11 52,407 3.1 (0.8–5.4) 55 350,543 20.6 (13.5–27.6)
All currently employed adults 6,982 52,785,257 39.5 (38.5–40.5) 7,359 55,811,322 41.7 (40.7–42.7) 11,669 89,111,151 66.6 (65.6–67.6)

Abbreviation: CI = confidence interval.
* The survey sample consisted of 17,464 U.S. workers aged ≥18 years who worked at least 20 hours per week.
Estimate has a relative standard error >30% and <50% and should be used with caution because it does not meet the National Center for Health Statistics’ standards of reliability.
§ Estimate had a cell size <10 and was removed from the results because it did not meet the National Center for Health Statistics’ standards of reliability.

Suggested citation for this article: Shockey TM, Luckhaupt SE, Groenewold MR, Lu M. Frequent Exertion and Frequent Standing at Work, by Industry and Occupation Group — United States, 2015. MMWR Morb Mortal Wkly Rep 2018;67:1–6. DOI: http://dx.doi.org/10.15585/mmwr.mm6701a1.

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