Recent Trends in Office Ergonomics

Environmental, Health & Safety International Communications Conference (EHSICC)

September 10, 2014

Raleigh, North Carolina

The field of study concerned with finding ways to keep people safe, comfortable, and productive while they perform tasks at work and home.

What is Ergonomics?

Fitting the task to the person

Before we begin, let’s see how observant you are?

Can you find the animal in the rose?

Can you find the hidden tiger?Clue: How about the “THE HIDDEN TIGER”

Ergonomics and theHuman Body

www.bodyworlds.com

Muscles Need…

• Circulation• Motion• Recovery• Efficient positioning• Efficient recruitment

When deprived of any of these factors, muscles are prone to FATIGUE and MSDs.

Ergonomic Stressors

Physical Ergonomic Stressors

1. Force2. Posture3. Movement

– Repetitive Actions– Static or Sustained Postures

multiple stressors = greater chance of injury

Force

• Overworked muscles experience fatigue

• Overuse is common when:– High work task forces are required– Forces are sustained for extended periods of time

– Small muscle groups are used for large amounts of force

Contact Force• When part of the body is pressed or leaning

on an edge or surface• Decreases circulation• Places pressure on nerves and soft tissues

• Joints have ranges of motion– Neutral postures in mid range– Extreme postures at end of range– Awkward postures between neutral and

extreme

• Extreme and awkward postures use time and energy inefficiently and can lead more quickly to fatigue

• Body more prone to injury when joints are positioned in awkward or extreme postures

Postures

Movement

• Jobs require combinations of tasks that are repetitiveor require little to no movement (static)

• Both can be harmful to the body

• Look to the extremes– Static/sustained postures– Repetitive movements

Breaks & Stretching

• 2-5 min break from posture every hour• Stretching facilitates circulation• Height Adjustable Workstations (More Later…)• Active Workstations (More Later…)

Musculoskeletal Disorders

Musculoskeletal Disorders

• MSDs

• Refers to damage or weakening of the musculoskeletal system

• May be one of two types:1. Cumulative Trauma Disorders2. Acute Trauma

Common Types of MSDs• Carpal Tunnel

Syndrome• Tendonitis• Tenosynovitis• Epicondylitis• Dequervain’s

Tendonitis

• Lumbar Strain/Sprain• Muscle Strain

• Tendons & median nerve in tunnel

• Swelling in tunnel canimpinge nerve

• Symptoms include:pain, tingling sensation, numbnessin fingers/palm

Carpal Tunnel Syndrome

Are We Build To Stand Or Sit?

Back posture when seated

ChairAdjustments in order1. Chair Height and Angle

Adjust height and angle so thighs are parallel to floor.

2. Lumbar Support HeightPlace lumbar support in small of back and have worker readjust to sit firmly against seat back.

3. Backrest AngleAdjust the backrest so that the worker is slightly reclined.

ChairAdjustments in order (cont’d)

4. Seat Pan DepthDepth should allow 3 fingers between back of knees and seat edge.

5. Armrest Height and WidthAdjust to slightly below elbow height and eliminate interference with desktop.

The width should be set so that the worker can get in and out without hip interference.

Keyboard– Locate directly in front of user.– Height allows elbows to maintain 90º angle while upper arms by

side (shoulders neutral).– Wrists should be straight, no keyboard tilt.

Pointing device– Place at same height as keyboard.– Keep as close as possible to keyboard.– Alternate hands when necessary.

Wrist rest for both keyboard and pointing device– Helps to eliminate or reduce contact stress.– Use one with low profile and soft padded material.– Use only as “rest”, do not use while fingers are typing.

Keyboard, Pointing Device,and Keyboard Tray

Monitor: Position and GlareMonitor position

• Locate directly in front of user.• Top row of characters even with seated eye height (lower the monitor

height if worker reads the screen out of the bottom lens of bi-focal lenses).

• Arm’s length away from user.• Monitor should be located perpendicular to windows or blinds should

be used to control natural light levels.

Monitor: Dual Screens• If both screens are used

equally, then the joint between the two screens should be aligned with the midline of the body.

• Primary screens should be located directly in front of the user, with the secondary located on the side of the dominant eye

Laptop as a Second Screen

If the laptop screen is used as a secondary monitor, it should be located at the same height and distance as the primary monitor.

Docking Stations & LaptopsWhen employees work primarily with a laptop, at minimum, the following external equipment should be supplied: Monitor(s) Pointing Device Keyboard

Often, this is done by connecting equipment through a docking station.

Docking Stations & Laptops• A laptop holder elevates the laptop display to eye level • An external keyboard and mouse allow him to sit back in

his chair and eliminate the awkward “laptop hunch.”

Document Holder• If the worker uses a source document frequently, it should be

located on a document holder.• Locate either between the screen and the keyboard or

directly to the side of the monitor to promote the use of neutral postures.

Height Adjustable WorkstationsThese workstations are highly

customizable • Choose either:

– A workstation that is split level, or– A workstation that is one level and outfitted

with a monitor armWHY?

Height Adjustable Workstations

• Some accommodate multiple monitors• Some have independent adjustability between monitors and

keyboards

Height Adjustable Workstations • Some accommodate document holders

What Does the Research Indicate?

6-Month Follow-Up: Comparison of Sit-to-Stand and Stand-Biased Desks in a Call Center

Mark Benden, CPE, PhDMeghan Kress, PhD

Research: Stand-Capable

Sit-Stand Adjustable Stand-Biased

Stand-Capable

Sit-Stand Adjustable

Research:

Stand-Capable

Stand-Biased

Research:

Baseline 3 months 6 months

X X X

X

X

X X

Research: Study Design

Data Collection

Accelerometers Online survey

Research:

Proportion of Time Sedentary

Research:

Proportion of Self-Reported Time Seated

Research:

• 76% of time sedentary• 78% of time sitting

– 1 hr. 2 min. reduction

• 75% of time sedentary• 67% of time sitting

– 1 hr. 55 min. reduction

Sit-stand adjustable Stand-biased

Research: After Six Months

Standing habits at 6 months for all stand-capable desk users (n=52)

% of Population that reported standing at all 88%

Average % of time reported standing 29% (range 0-100%)

Average transitions reported from seated to standing per day

3.1 (range 1-10)

* Combined sit-stand and stand-biased participants

Research: Summary

Reasons to stand

1) Increased body comfort (74%)

2) To stay alert (64%)3) To burn more calories (52%)

Reasons not to stand

1) None (49%)2) Decreased body comfort

(26%)3) Energy required (9%)

Research: Subjective Feedback

• 91% would make the switch again

• 49% experienced increased focus and alertness

• 40% experienced increased levels of energy

• 29% experienced increased productivity

Research: Subjective Feedback

Seated control group reported higher prevalence (statistically significant) of pain/discomfort reported in the highlighted areas.

Research: Discomfort

Research: Beware: Stand-Capable Workstations Could Create A

Privacy Issue In Tight Cubicles with Low Profile Dividers

Active WorkstationsActive workstations designed to increase an

employee’s energy expenditure throughout the day, in order to help reduce the effects of sedentary work.

Examples include: Treadmill workstations, Bicycling workstations, Stair climber desks

Walking WorkstationsHealth Advantages of Walking

Are Well Established :• Stimulating blood flow to the

brain• Reduced risk of heart disease• Reduced risk of obesity But What About Productivity and

Risk of Injury…Let’s look at some of the limited research…

Walking Workstations: Research• 2011 Mayo Clinic study of 11 medical

transcriptionists found: – Typing speed and accuracy slowed by 16% while

walking, compared with sitting.

• 2009 University of Tennessee study of 20 participants found:– Treadmill walking resulted in an up to 11%

deterioration in fine motor skills like mouse clicking, and dragging and dropping, as well in as cognitive functions like math-problem solving.

Wieczner, Jen, The Wall Street Journal, Falling Down on the Job?, Updated January 29, 2013.

Walking Workstations: Research• The U.S. Consumer Product Safety Commission

maintains the National Electronic Injury Surveillance System, which tracks product-related harm.

– In 2011, treadmill injuries in any context (home, office or gym) comprised 37% of all exercise-equipment mishaps, a Wall Street Journal analysis of the database found.

– Reported treadmill injuries included foot lacerations, knee sprains and chest contusions.

Wieczner, Jen, The Wall Street Journal, Falling Down on the Job?, Updated January 29, 2013.

Walking/Cycling Workstations: Research• Researchers Straker, Levine and Campbell (2009) investigated

the effect of active workstations on the performance of computer operators. Specifically, they tested four workstations: – Riding a stationary bicycle at two different speeds– Walking on a treadmill at two different speeds– Sitting – Standing

• For each condition, they measured:– Actual speed & accuracy of mousing and keyboarding – Subjects' perceived effects on these performance measures– Heart rate and the subjects' perceived exertion levels

Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: Research• Subjects included 14 male and 16 female experienced computer

operators, 15 of whom were touch typists and 15 whom were not.

• The researchers tested subjects while performing:– Typing task only– Mousing task only– Combined mousing and typing task

Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: Research• The researchers found no significant difference in performance

measures between the sitting and standing workstation conditions

• But did find statistically significant decreases in performance under walking and cycling workstation conditions.

• Let’s look at the details…

Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: ResearchTyping performance while walking on a treadmill:

– 6% decrease in actual speed – 3% increase in actual error rate– There were no actual performance differences between the

walking speeds

Typing performance while riding a stationary bicycle:– 3% decrease in actual speed– 0.7% increase in actual error rate– There were no actual performance differences between the

cycling speedsBudnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: ResearchMouse pointing performance while walking on a treadmill:

– 14% decrease in actual speed – 106% increase in actual error rate– There were no actual performance differences between the

walking speeds

Mouse pointing performance while riding a stationary bicycle:– 5% decrease in actual speed– 61% increase in actual error rate

Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: ResearchCombined typing and mousing performance while walking on a treadmill:

– 15% decrease in actual speed – 35% increase in actual error rate– No actual performance differences between the walking

speedsCombined typing and mousing performance while riding a stationary bicycle:

– 3% decrease in actual speed– 35% increase in actual error rate– No actual performance differences between the cycling

speeds Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Walking/Cycling Workstations: ResearchSummary• Organizations are looking for ways to increase activity levels

for reasons such as health and weight control• However this research suggests there can be a price to pay in

terms of reduced productivity and increased error rates • Customers should weigh the health benefits against the

potential costsReference• Straker, Leon; Levine, James; Campbell, Amity, Human Factors,

Volume 51, Number 6, December 2009, pp. 831-844(14), available online at the time of this writing at http://hfs.sagepub.com/content/51/6/831.abstract

Budnick PhD, CPE, Peter, The Ergonomics Report, The Effects of Walking and Cycling Computer Workstations on Keyboard and Mouse Performance, October 4, 2010.

Active Workstations: General Thoughts• Many ergonomists and safety & health

professionals are concerned with the safety risk associated with these products.

• Research is generally indicating a decrease in typing and mousing performance.

• Yes, an employee’s energy expenditure may increase as well as alertness in some cases but at what cost.

• Many ergonomists are considering the value of these products as an alternative (secondary) workstation that could shared throughout the day as the individual performs non-typing related tasks (phone calls, meeting, reviewing e-mails, etc.).

Tablets

Tablets are designed for short term use• Similar stressors to laptops• Variety of potential postures during use• Posture Concerns

– Extended use in any one posture – Neck, Back, Elbows, Shoulders, Wrists, Hands– Touch screen interface eliminates touch-to-type

technique

Tablet Solutions

Various stand designs try to reduce awkward postures

Touch Screen: Research• Objective: The aim of this study was to evaluate the effect of

sitting and standing on performance and touch characteristics during a digit entry touch screen task in individuals with and without motor-control disabilities.

• Background: Previously, researchers of touch screen design have not considered the effect of posture (sitting vs. standing) on touch screen performance (accuracy and timing) and touch characteristics (force and impulse).

Amrish O. Chourasia, Douglas A. Wiegmann, Karen B. Chen, Curtis B. Irwin, and Mary E. Sesto Effect of Sitting or Standing on Touch Screen Performance and Touch Characteristics Human Factors: The Journal of the Human Factors and Ergonomics Society August 2013 55: 789-802, first published on January 11, 2013

Touch Screen: Research• Method:

– Participants with motor-control disabilities (n = 15) and without (n = 15) completed a four-digit touch screen number entry task in both sitting and standing postures.

– Button sizes varied from 10 mm to 30 mm (5-mm increments), and button gap was 3 mm or 5 mm.

Amrish O. Chourasia, Douglas A. Wiegmann, Karen B. Chen, Curtis B. Irwin, and Mary E. Sesto Effect of Sitting or Standing on Touch Screen Performance and Touch Characteristics Human Factors: The Journal of the Human Factors and Ergonomics Society August 2013 55: 789-802, first published on January 11, 2013

Touch Screen: Research• Results:

– Participants had more misses and took longer to complete the task during standing for smaller button sizes (<20 mm).

– At larger button sizes, performance was similar for both sitting and standing.

– In general, misses, time to complete task, and touch characteristics were increased for standing.

– Although disability affected performance (misses and timing), similar trends were observed for both groups across posture and button size.

Amrish O. Chourasia, Douglas A. Wiegmann, Karen B. Chen, Curtis B. Irwin, and Mary E. Sesto Effect of Sitting or Standing on Touch Screen Performance and Touch Characteristics Human Factors: The Journal of the Human Factors and Ergonomics Society August 2013 55: 789-802, first published on January 11, 2013

Touch Screen: Research• Conclusions:

– Standing affects performance at smaller button sizes (<20 mm).

– For participants with and without motor-control disabilities, standing led to greater exerted force and impulse.

Amrish O. Chourasia, Douglas A. Wiegmann, Karen B. Chen, Curtis B. Irwin, and Mary E. Sesto Effect of Sitting or Standing on Touch Screen Performance and Touch Characteristics Human Factors: The Journal of the Human Factors and Ergonomics Society August 2013 55: 789-802, first published on January 11, 2013

Ball Chairs• Ball chairs (exercise ball, stability ball, or abdominal ball

chairs) are intended to increase motion in the low back and to diminish the effects of static working postures for users.

• No back support, users tend to lean forward more than with office chairs

• More trunk motion, but increased spine compression and low-back muscle fatigue

What Does the Research Indicate?

• A 2009 British study concluded that the posture of 28 subjects who sat on a stability ball was just as poor as those who sat in a chair

• A 2009 Dutch study published in Applied Ergonomics, the balls produced 33% more “trunk motion” but also produced increased compression of the vertebrae.

Wieczner, Jen, The Wall Street Journal, Falling Down on the Job?, Updated January 29, 2013.

Ball Chairs: General Thoughts• Most ergonomists and safety & health professionals are

very concerned with the safety risk associated with non-captured ball chairs (photo on right).

• Many ergonomists are concerned with a captured ball with no back support…increased fatigue (center photo).

• Captured ball with back support is the better opinion but many ergonomist are still afraid to recommend it as the primary task chair Safety concern?

Kneeling Chairs• User’s body weight supported by knees or shins• With no back support, users tend to lean forward

more than with traditional office chairs• Not typically adjustable (must be fitted)• May be beneficial for those with tailbone pain or

needing a more open hip angle, similar to forward seatpan tilt.

Smart Phones• Like tablets, phones are intended for short,

intermittent use• Primarily used with thumbs

– Use 2 hands when possible• Posture Concerns

– Extended use in any one posture – Neck, Back, Elbows, Shoulders, Wrists, Hands– Touch screen interface eliminates touch-to-type technique

Hoteling at the Office

Provide workstations with:Height Adjustable Monitor or Laptop StandAdjustable ChairKeyboardKeyboard TrayDocking StationPointing DeviceFootrest

Telecommuting

Just because it’s home doesn’t mean it’s not an office.

Follow standard office benchmarks, especially:» Allow for knee clearance» Separate monitor and keyboard» Have a designated work space» Avoid directly facing windows

Lighting• Task lights using LED and compact fluorescent (CFL) light

sources are far more cost- and energy-efficient than comparable incandescent bulbs.

• CFLs use 25% of the energy of incandescent bulbs and last up to 10 times longer.

• The latest LEDs use as little as 10% of the energy and last up to 60 times longer than incandescents.

OK…You have one more chance!

What is it?What is it now?

Finally…Just For Laughs!!!

Any Questions?