Sedentary Work & the Paradox of Occupational Physical Activity

Jack [email protected]

@JackDennerlein

October 2019

Sedentary Work & the Paradox of Occupational

Physical Activity

http://www.northeastern.edu/ergonomics/

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There is a public health paradox in ergonomics — we seek to design work that fits a large population and reduces physical loading on muscles, bones and tissues. Yet, we know that physical activity is important to reduce chronic illnesses like diabetes and heart disease

Can we design work and workstations that allow for more opportunities to exercise? Does standing at a computer workstation improve health outcomes as well as performance? Or does it introduce other health problems associated with sustained standing? Future research needs to ask these important questions

Dennerlein The Paradox of the Perfect Chair: Is all that sitting really killing us. The New York Times Room for Debate, 2010 April 23. http://roomfordebate.blogs.nytimes.com/2010/04/23/is-all-that-sitting-really-killing-us/

2010

TOTAL SITTING TIME IS NOT GOOD

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5Rempel (2017)

EVIDENCE ABOUT SITTING AT WORK

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The annual rate of Coronary Heart Disease for Drivers 2.7 per 1,000Conductors 1.9 per 1,000

Morris, J.N., Heady, J.A., Raffle, P.A.B., Roberts, C.G., and Parks, J.W., 1953. Coronary heart disease and physical activity of work. Lancet 265, 1053-1057.

1953

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Church, Tudor-Locke, Katzmarzyk et al. . Trends over 5 decades in U.S. occupation-related physical activity and their associations with obesity. PLoS One. 2011;6(5): http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0019657

2011

Efforts to reduce sedentary time at work

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Pronk Prev Chronic Dis. Oct 2012;9:E154. PMID: 23057991

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Intervention group (n=23) Control group (n=10)

2012

• Introduction of the WorkFit sit-to-stand devices among a group of highly active, fit, normal weight, apparently healthy, mostly female employees with relatively sedentary work tasks:– Increased non-sitting time by more than an

hour per day– Reduced Pain in

» upper back, neck and shoulder pain

– Improved mood states– Increased face-to-face time during work

Pronk Prev Chronic Dis. Oct 2012;9:E154. PMID: 23057991

• Participants felt the WorkFit devices made them feel:– More comfortable (87%)– More energized (76%)– Healthier (75%)– More focused (71%) – More productive (66%)– Happier (62%)– Less stressed (33%)

Removal of the devices after four weeks eliminated most improvements generated due to the intervention, in many cases to below baseline levels

• There is insufficient evidence to make firm conclusions regarding the effects of installing height-adjustable workstations on sedentary behaviour and associated health outcomes in office workers.

12Tew et al., Occup Med (Lond). 2015 Jul;65(5):357-66

2015

13https://www.ncbi.nlm.nih.gov/pubmed/29677023 J Occup Environ Med. 2018 Jul;60(7):e319-e320.

2018

• Energy Expenditure for standing versus sitting• = 0.15 (0.12 – 0.17) kcal/min (46 studies with 1,184 participants)• = 9 kcal for every hour spent standing instead of sitting• = 54 kcal if people stood for 6 hours per day (instead of sitting)

14Saeidifard et al. Eur J Prev Cardiol. 2018 Mar;25(5):522-538. Slide from Peter Smith, IWH

2018

What is 54 kcal?

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2018

Slide from Peter Smith, IWH

Adding dynamic workstations increasing PA at work

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Adding dynamic workstations

Impact on Productivity• Appears to impact

– fine motor control tasks – thinks requiring the mouse (<10% completion time)

• Does not impact– selective attention – processing speed or – reading comprehension

Impact on Health• Appears to improve

– Health of obese workers– Hip circumferences– lipid and metabolic profiles

• Challenges in implementations– Space and resource– Noise, – Shoes– Risk of injury

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John et al. J Phys Act Health. 2009 Sep;6(5):617-24.John et al. J Phys Act Health. 2011 Nov;8(8):1034-43.Huysmans et al, Ergonomics in Design 2015 4-8

IS SITTING AT WORK BAD FOR YOU?I asked my students this question.

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The annual rate of Cardiac Heart Disease for Drivers 2.7 per 1,000, Conductors 1.9 per 1,000

Morris, J.N., Heady, J.A., Raffle, P.A.B., Roberts, C.G., and Parks, J.W., 1953. Coronary heart disease and physical activity of work. Lancet 265, 1053-1057.

1953

Tavia Allen PT/s, Meghan McPhee PT/s,

Kayla Wegener B.S., PT/s

The Impact of Occupational Sitting on

Health Outcomes: Where do we stand?

A Scoping Study

http://www.northeastern.edu/ergonomics/

2018

Does occupational sitting have a negative impact on health outcomes?

Scoping review of the literature• Identify relevant papers• Extract Data• Reviewed results• Synthesized findings from relevant

studies.

Criteria• Measured exposure of occupational

sitting• Measures a health outcome• Examines an association• Published after 2005 • Published in English

Does occupational sitting have a negative impact on health outcomes?

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Does occupational sitting have a negative impact on health outcomes?

• 14 papers encompass upwards of

• 130,000 participants from • 20 different countries from a

variety of industries

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24Rempel and Krause (2018)

IS STANDING AT WORK THAT GOOD FOR YOU?

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Dennerlein The Paradox of the Perfect Chair: Is all that sitting really killing us. The New York Times Room for Debate, 2010 April 23. http://roomfordebate.blogs.nytimes.com/2010/04/23/is-all-that-sitting-really-killing-us/Duchame J. Six Tips for Using Standing Desks Correctly, Boston Magazine http://www.bostonmagazine.com/health/blog/2016/05/10/standing-desks/

If sitting [at work] is the new “smoking”, we have to remember that standing is an old “smoking”

Can we design work and workstations that allow for more opportunities to exercise? Does standing at a computer workstation improve health outcomes as well as performance? Or does it introduce other health problems associated with sustained standing? Future research needs to ask these important questions

2010

Standing at work is not good.• Increases low back pain• Increase risk of CVD

• Standing Increases Carotid Athersclerosis– 4-year Change of Carotid Intima

Media Thickness (IMT), adjusted for Age, Technical, Physical and Psychosocial Job Factors, Income, Biological and Behavioral Factors: Men with IHD

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Krause et al. Standing at work and progression of caro7d atherosclerosis. SJWEH 2000; 26(3): 227-236 https://www.ncbi.nlm.nih.gov/pubmed/10901115https://en.wikipedia.org/wiki/Intima-media_thickness

2000

Standing at work is similar to smoking• Increases low back pain• Increase risk of CVD

• Standing Increases Carotid Athersclerosis– 4-year Change of Carotid Intima

Media Thickness (IMT), adjusted for Age, Technical, Physical and Psychosocial Job Factors, Income, Biological and Behavioral Factors: Men with IHD – smoking is an independent, yet has similar effect

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Krause et al. Standing at work and progression of caro7d atherosclerosis. SJWEH 2000; 26(3): 227-236 https://www.ncbi.nlm.nih.gov/pubmed/10901115https://en.wikipedia.org/wiki/Intima-media_thickness

2000

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Hazard ratios for occupational exposures and incident heart diseaseover a 12-Year Period in Ontario, Canada. (N = 7,320)

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ref ref

Adjusted for all covariates Additional adjustment for HB and BMI

Smith et al, Am J Epidemiol. 2018 Jan 1;187(1):27-33

2018

OCCUPATIONAL PHYSICAL ACTIVITY IN GENERAL

Modern day farmer to wife who works in public health research: “Why do you have to go the gym? You could simply work in the fields with me and not go to the gym”

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The health paradox of occupational physical activity

31Holtermann et al., Br J Sports Med. 2012 Mar;46(4):291-5.

2012

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2019

http://dx.doi.org/10.1136/bjsports‐2017‐097965

OKAY, SO WHAT CAN WE DO?

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They give me freedom similar to the way commuting by bicycle frees me from sitting in my car stuck in rush hour traffic. I can stand up and I can move more frequently while still interacting with my computer and conducting the business of the day

Sit-Stand Workstations:Benefits other than cardiovascular

BEST PRACTICES

Use sit-stand workstations• Combined with training, they

provide adjustability• Changing between sitting and

standing increases postural variability

• They give workers control over their workstations

• Reduce discomfort

Increase breaks from sitting• Breaks increase productivity• Increase postural variability• Reduce discomfort• Opportunity for small bouts of

physical activity

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Jack [email protected]

@JackDennerlein

September 2019

Sedentary Work: Evidence and Approaches for

Combating Sedentary Work

http://www.northeastern.edu/ergonomics/