Ergonomics & Musculoskeletal Injuries in Agriculture:

Preventing the industry’s most widespread health & safety problem

Larry Chapman & James Meyers

Univ. of Wis. Madison &Univ. Of Calif. Berkeley

Comparisons based on employer reporting for musculoskeletal disorders capture only data from a few, very large operations (not representative of the production ag labor force):

Table 1. US large farm rates of musculoskeletal health problems per 10,000 full time equivalent workers.

disorders carpal

associated with sprains, back tunnel

industry sector repeated trauma strains pain syndrome tendonitis

agricultural production-crops 9.9 112.7 7.9 1.7 2.3

cash grains - 77.6 - - -

field crops, except cash grains - 81.7 - - -

vegetables and melons 15.0 94.7 13.2** - -

fruits and tree nuts 1.7 123.3 8.5* - -

horticultural specialities 20.5 124.9 7.9 3.8 2.9

general farms, primarily crop 1.3 111.9 - - -

agricultural production-livestock 27.6 126.6 8.8* 2.9 1.6

livestock, ex. dairy & poultry 14.6 152.8* 18.6** - -

dairy farms - 72.2 - - -

poultry and eggs 50.1* 122.7 2.4 5.7* 2.9

animal specialties 83.1** 113.7 - - -

agricultural services 8.7 86.5 3.5 1.6 -

crop services 36.0 96.3 1.7 - 3.9*

veterinary services 6.6 40.0 - - -

animal services, ex.veterinary 4.9 53.5 11.9** - 3.4*

farm labor and management services 0.9 66.4 - - -

landscape & horticultural services 5.6 114.6 5.4 1.9 -

agricultural production total 13.9 115.9 8.1 1.9 2.1

all private industry average 32.0 92.5 5.6 3.4 2.1

Note: ** > two times the private industry rate, * > one and one half times the private industry rate. US Bureau of Labor Statistics, Washington DC: US Department of Labor, 1999 (excludes farms with less than 11 employees)

Population-based surveys (NHIS) suggest exposures to musculoskeletal hazards are as high or higher for all ag- forestry-fishing compared to other occupational groups

Table 2. Percent of US adults reporting exposures to musculoskeletal hazards in the last year.

repeated strenuous repeated bending, bending or twisting hand operation of

physical activity twisting or reaching of arms or wrists vibrating machinery

- any daily exposure -

agriculture, forestry and fishing 70.6 82.1 73.4 42.8

blue collar occupations 55.9 71.7 56.5 40.8

service sector occupations 40.1 61.8 73.7 18.8

white collar occupations 17.4 28.6 37.0 6.5

- two or more hours of exposure per day -

agriculture, forestry and fishing 52.8 65.2 59.2 28.4

blue collar occupations 44.1 62.4 66.4 28.4

service sector occupations 26.0 50.2 48.9 10.3

white collar occupations 9.8 21.3 32.2 3.5

Source: US DHHS. National Health Interview Survey Occupational Health Supplement, 1988. Vital and Health Statistics 1993; Series 10, Number 106, (n=27,408).

Population-based surveys (NHIS) also suggest that

· reports of musculoskeletal health problems are more common than reports of any work injury for all ag- forestry-fishing occupations

· but neither reports of musculoskeletal health problems nor work injury for all ag- forestry-fishing occupations are high compared to rates in blue collar, service sector or white collar occupations

Table 3. Percent of US adults reporting occupational health problems in the last year.

repeated trouble carpal

any work with back, tunnel

injury neck or spine syndrome tendonitis

agriculture, forestry and fishing 10.0 18.2 0.9 1.4

blue collar occupations 13.8 21.4 1.9 3.8

service sector occupations 8.7 20.1 1.3 2.5

white collar occupations 4.5 17.8 1.3 3.5

Source: US DHHS. National Health Interview Survey Occupational Health Supplement, 1988. Vital and Health Statistics 1993;

Series 10, Number 106, (n=27,408).

Population-based surveys (NHIS, FFHHS) that break down all ag- forestry-fishing occupations into smaller job groupings show that

· production ag back pain is as high or higher than all other occupations

· back pain on small & family farms may be 50- 300% higher than ave for all farm sizes

Table 4. Population-based studies of individuals working on farms of all sizes reporting back pain.

US National Health Interview Survey, 1988 back pain > one wk last yr

males:

all industries (n=15,000) 10.7%

agricultural production-crops (n=200) 16.7%

agricultural production-livestock (n=223) 15.7%

females:

all industries (n=15,000) 6.7%

agricultural production crops (n=74) 10.8%

US Colorado Farm Family Health and Hazard Survey, 1993

all small and family farm respondents (n=458) 26.2%

dairy farmers 43.0%

field crop farmers 27.0%

livestock farmers other than dairy 25.0%

Holland Central Statistics Office Survey, 1983-85 back pain quite often

males:

all industries (n=5,840) 25.3%

all agriculture (n=388) 27.3%

farm operators (n=204) 27.0%

farm workers (n=163) 28.2%

females:

all industry (n=2,908) 28.9%

all agriculture (n=52) 21.2%

Sources: US NHIS data - Guo et al., 1999; Colorado FFHHS data - Xiang et al., 1999; Holland CSOS data - Hildebrandt, 1995b.

Discomfort reports w/ a common instrument are high for ag vs other & for certain ag work

Table 5. Nordic questionnaire reports of musculoskeletal discomfort in the last year from farms of all sizes.

lower wrist- elbow neck-

back knee elbow hand wrist-hand neck shoulder shoulder

agricultural production-crops:

fresh market vegetables US (n=102) 66** 31* 23*** 36*** - 37** 37* -

fresh market veget. Holland (n=167) 49 15 - - 19 - - 45**

greenhouse tomatoes Britain (n=56) 61** 18 11 34** - 46*** 64*** -

berry US (n=26) 62** 23 12 39*** - 42*** 46** -

tree fruit Germany (n=465) 57* 40*** 20*** 29** 38** 38*

fruit Holland (n=35) 33 35** - - 39*** - - 33

potted plants Holland (n=137) 51 18 - - 20* - - 32

tree nursery Holland (n=98) 66** 27 - - 37*** - - 58***

mushrooms Holland (n=56) 49 18 - - 31** - - 32

cut flowers Holland (n=197) 48 23 - - 16 - - 33

flower bulbs Holland (n=91) 63** 23 - - 17 - - 35*

agricultural production-livestock:

dairy US (n=621) 49 39** 15* 23* - 26 32 -

dairy Sweden males (n=2,081) 55* 41*** 18* 18 - 25 37* -

dairy Sweden females (n=161) - - - - 58*** 35** 50** -

poultry Holland (n=82) 51* 22 - - 16 - - 30

hogs Holland (n=53) 62** 18 - - 20 - - 31

hogs Denmark (n=25) 60* 12 4 4 - 32* 20 -

mixed crops&livstk Holl. (n=343) 49 25 - - 23 - - 37*

nonagricultural industry groups:

construction US (n=2929) 70** 46** 25*** 43*** - 42* 42* -

cosmetologists US (n=404) 62** 28 15* 55*** - 54*** 59*** -

computer operators US (n=682) 52* 15 6 24* - 50*** 25 -

physical therapists US (n=928) 45 11 8 29** - 25 19 -

all industry norms (n>3,450) 40±10 25±5 10±5 12.5±7.5 12.5±7.5 25±5 25±10 25±10

Note: *** > three standard deviations (SD) above mean for all occupation norms, ** > two SD above mean, * > one SD above mean

Sources: Holland: Hildebrandt, 1995a; US: Chapman et al., 2000; Sweden: Gustafsson et al., 1994; Stal et al., 1996; Britain: Palmer, 1996; Denmark: Christensen et al., 1992; Germany: Calisto, 1999; US: Rosecrance et al., 1997.

Univ of Calif found musculoskeletal disorder rates per 1000 (e.g. 40 in plant nurseries and 80 in winegrape vinyards) that ranked with the highest reported rates per 1000 for disorders due to repeated trauma in all US industries (e.g. 92 in meat packing, 91 in knit underwear, 71 in motor vehicles)

Table 6. Rates & Types of Musculoskeletal Disorders in Selected Groups

rate total no. no. of no. of no. of Lost Work

per 000 of MSDs back upper ext. other Days

(rate per 000 for all musculoskeletal disorders including backs)

Calif plant nurseries 40 85 26 39 20 1246

Calif winegrape vineyards 80 29 20 6 3 435

(rate per 000 for disorders due to repeated trauma w/o backs)

All Private US industries 3.2

Highest All US Ag Industries

poultry & eggs 5.0

animal specialities 8.3

Highest All US nonAg Industries:

meat packing plants 92.2

knit underwear mills 91.0

motor vehicles and car bodies 71.1

Sources: NIOSH project reports of the UC Agricultural Ergonomics Research Center, US Bureau of Labor Statistics, Washington DC: US Department of Labor, 1999 (excludes farms with less than 11 employees)

We estimate that the direct costs of musculoskeletal disorders in production may be in the range of $167 million to $4.28 billion per yr

Table 7. Size of the workforce, rates of disorders, costs of disorders and total direct/worker comp-health costs

Size of the workforce = 6.69 m

(based on 1.91 m crop and animal production farms w/ 3.5 employees per farm)

Rate of musculoskeletal disorder incidence = 5 per 1000 to 80 per 1000

no. per yr direct direct

rate per 000 in prod ag w/ cost per yr cost per yr

6.69 m at $5K per at $8K per

BLS US meatpacking 92.2

BLS US motor vehicles 71.1

Calif winegrape vineyards 80 535,200 2,676,000,000 4,281,600,000

Calif plant nurseries 40 267,600 1,338,000,000 2,140,800,000

BLS animal specialities 8.3 55,527 277,635,000 444,216,000

BLS poultry & eggs 5 33,450 167,250,000 267,600,000

BLS US all private industry 3.2

BLS US all ag & ag services 1.3

Average direct cost per musculoskeletal disorder = $5,000 per case to $8,000 per case

(average worker comp claim cost for a work-related upper extremity disorder

$7083-8250 in Silverstein B et al. Claims incidence of work-related disorders of the upper extremities: Washinton State, 1987-1995. Am J Public Health 1998;88:1827.

$8070 in Webster BS, Snook SH. The cost of compensable upper extremity trauma disorders. J Occup Med 1994;36:713.

Summary:

• Only the largest farms w/ 11 or more employees currently report w/ OSHA 200 forms so most of the production ag workforce gets missed in Table 1. BLS rates per 000 for production ag for “disorders to due repeated trauma” are low compared to the all US private industry average (0.99 crops, 2.76 livestock vs. 3.20 all us private industry) and production ag rates for back pain are not much higher (0.79 crops, 0.88 livestock vs. 0.56 all us private industry) - see Table 1

• Population-based NHIS surveys are an improvement over current OSHA 200 for reporting because they evaluate a nationally representative sample of employees. More ag-forestry-fishing occupation workers report exposures to musculoskeletal hazards than do blue collar, white collar or service sector workers - see Table 2. However, fewer ag-forestry-fishing workers report repeated trouble w/ back neck or spin, carpal tunnel syndrome or tendonitis than do blue collar, white collar or service sectors worker. 18.2% of ag-forestry-fishing workers reported “repeated trouble w/ back neck or spine” in the last year but only 10% reported “any work injury”- see Table 3

• Ag-forestry-fishing is a broad category. When reanalyzed to include just production ag, the percent of workers reporting “back pain for more than 1 wk last yr.” is higher than the average for workers from all US private industries (16.7% crops, 15.7% livestock vs. 10.7% all us private industry) - see Table 4

• Population-based FFHH survey data from small and family farms in Colorado are even higher for , the percent of workers reporting “back pain for more than 1 wk last yr.” (26% overall, 43% dairy, 27% crop) see Table 4

• US and European studies using a common, norm-referenced instrument have shown prod ag workers typically report discomfort more often than workers in other industries (i.e. percent w/ discomfort greater than one standard deviation above norm for back in 11 of 17 studies, hand-wrist in 5 of 7, elbow in 4 of 6, elbow or hand-wrist in 6 of 11, neck in 6 of 8, shoulder in 6 of 8, neck or shoulder in 4 of 10) - see Table 5

Conclusions:

• rates of exposures to musculoskeletal hazards are very likely to be higher in prod ag work than most other occupations

• rates of diagnosed or diagnosable back and upper extremity musculoskeletal injury and illness combined in prod ag work are very likely to be higher (perhaps 50-100% higher) than rates of traumatic injury

• rates of diagnosed or diagnosable back and upper extremity musculoskeletal injuries and illnesses are very likely to be higher in prod ag work than most other occupations

• musculoskeletal disorders are likely costing prod ag employers $1-4 billion annually in direct costs, perhaps as much as 2-10 times that figure when indirect costs are included

Recommendations:

• improve surveillance of work, work hazard exposures, and musculoskeletal injuries, illnesses, discomfort and disability to a level of understanding comparable with the understanding of traumatic injuries in production ag

• study the work and the exposures to musculoskeletal hazards and then identify or develop safer production methods and labor aids plus document their advantages

• conduct and evaluate region-wide, community-based interventions by commodity to persuade managers of production ag operations to adopt safer production methods and labor aids