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Ergonomic Design

Questions and Answers from Humantech’s Recent Webinar on Benchmarking Ergonomics Programs

by Walt Rostykus, CPE

Humantech recently presented a short web course entitled Keys to Ergonomics Program Success on December 14th. We received some great questions and wanted to share our response to those. We’d love to hear if you agree (or disagree) and what you company is doing to successfully manage workplace ergonomics.

Q: You said that online training and assessments are being used for offices.  What should I look for in a good office ergonomics software program?

A: There are several online applications available today billed as “office ergonomics software”.  They can be categorized into two general types: stretching and break programs, and assessment and training programs.  The first type focuses on personal health and wellness and has minimal effect on reducing the causative factors of musculskeletal disorders (MSDs).  It is our experience that people tire of them and stop their use within 1 to 4 months.  The second type are what we mentioned in the webinar. These are designed to provide awareness training and/or lead people to assess their workstation set up make adjustments.  This approach is known to reduce MSD risk factors present in office and computer workstations.  Features to look for include:

  • A focus on identifying and addressing MSD risk factors in office/computer tasks
    including standard office and remote (ex. Home, hotel, etc.) office workplaces.
  • Training that is SCORM compliant to align with a Learning Management System (LMS),
  • Assessment questions which focus on identification of MSD risk factors in the workplace rather than personal health.
  • Results of the assessment provided immediately upon completing the assessment questions, provide a measure of relative risk present, identify areas of concern by body part or workstation elements, and provide easy to implement solutions that are specific to the issues/risk factors identified.
  • Solutions that pursue adjustment of the existing workstation and equipment before recommending purchase of new equipment, and present only the furniture and devices approved by and provided by the organization.
  • Data from assessments and solutions which are available to the program manager to track trends of use and results.
  • Assessments and solutions that are easily tailored by the organization to reflect the local program and offerings.

Q: I disagree that stretching is not part of ergonomics.  What is your reason for saying it is not?  Isn’t it effective?

A: NIOSH defines occupational ergonomics as “the science of fitting workplace conditions and job demands to fit the capabilities of the working population”.  In other words, making the workplace fit the person.  Stretching is part of wellness and fitness that focuses on changing the capabilities of an individual, not changing the workplace.  Although many companies include stretching as part of their programs, current research has not proven any effectiveness of company driven stretching programs on the reduction of first time MSD injuries.

Q: If we are currently a “reactive program”, what should we do first to move to being more “proactive”?

A: The first step is to transition from the lagging measures of injuries and discomfort to the proactive measure of MSD risk factors.  This will get your program focused on identifying and preventing the causes of MSDs (and discomfort) before an incident happens.  This will also change your program goal from injury reduction to risk reduction.

Q: What are some quantitative assessment tools available to use?

A:  REBA (Rapid Entire Body Assessment) and BRIEF (Baseline Risk Identification of Ergonomic Factors) are two whole body risk assessment tools that provide scores of risk level.  The NIOSH Lifting Equation is a quantitative measurement tool used for lifting.   When selecting assessment tools take time to understand what they are based on (i.e. research), their ease of use, and the definition of scoring.  Ensure that they are valid, repeatable, reliable, and provide the definition within a single task and between tasks.

Q: Is online training really effective?

A:  The effectiveness of training, online or in person, depends on the intended learning objective, class content, and methods for verifying learning.  For awareness of ergonomics (both office and non-office), and for teaching principles of ergonomics, good online training classes are effective.  However, skills training like conducting assessments, applying design criteria, selecting solutions, do require some hands-on application and feedback from the instructor.  Portions of skills training are better completed through classroom or in-person coaching, not online.

Q: What did companies say about the effect of the recession on their ergonomics program?

A: The impact of the recent economy described by participating companies can be broken out into three categories; No Impact – 23%, Minor Impact – 59%, and Greater Impact – 18%.  These varied more by the type of industry and culture of the organization rather than the maturity of their ergonomics program.

-     No Impact: These companies described no significant impact on the resources or focus of their ergonomics program.

-     Minor Impact:  These companies experienced some constraints on funding and the availability of people to participate in the ergonomics program.

-     Greater Impact:  These companies have significant loss of funding and key people supporting their ergonomics program. They also made some changes in their overall program goals and measures.

Q: I wonder what challenges you have seen in consulting with ergonomics for industry due to 86% of the United States population now is Overweight and/ or with 1 or more chronic diseases, that was that was published on Oct 17th, 2011 by Gallop from their “Well-Being Index”?

A: The greatest impact of obesity on workplace ergonomics we’ve seen is the effect on reach distance and movement of large employees.  Winnie Ip, CPE and Humantech’s Director of Consulting presented this challenge and solutions at the 2011 ASSE Conference.  The other impact we’ve seen is with patient handling, specific moving bariatric patients.  This has increased the weight that healthcare professionals are expected to move during manual patient handling.

Q: What about investment, were you able to determine how much money companies invested in their ergonomics program based on employee headcount or revenue?

A:  Money is always a tough topic to discuss, even in benchmarking.  When we asked about the annual investment in the ergonomics program, 76% of participants did not know how much was spent.  So we asked people to identify general ranges of investment.  They were:

<$500,000  -  50%

$500,000 to $1Million  – 44%

>$1Million – 6%

Granted these numbers are rough estimates but we calculated that companies invest 0.0043% .05% (median = 0.0046%) of their annual revenue on ergonomics.



Ergonomics of Airplanes: What Makes Us Comfortable?

By Mike Hoonhorst, AEP

Mike HoonhorstDue to the nature of our jobs as consultants, we often find ourselves on an airplane, traveling across the country, and even across the world.  And with the holiday season in full swing, you too may find yourself flying soon.  Almost all of us have probably said, “I cannot wait to get off of this airplane!”  Having frequently been in this position, I decided to do some research on the ergonomics of flying.  What I found was both obvious and surprising at the same time.  There are many variables that affect the way passengers think of comfort when flying.

The most obvious is the lack of leg room, especially on longer flights.  We’ve all experienced discomfort in the back of our legs, which is only amplified when we can’t stretch our legs because there is simply not enough room.  Less legroom generally results in higher discomfort ratings, as reported in Possibilities to Improve the Aircraft Interior Comfort Experience. But the authors of this 2011 research article in Applied Ergonomics (Vink, Bazley, Kamp and Blok) found that there are many other reasons that passengers may find air travel uncomfortable.  The authors found a correlation between hygiene and comfort.  If the aircraft has clean seats and windows, with a bright, new-looking interior, passengers were more likely to experience a comfortable flying experience.  Passengers also found flying on newer planes to be a better experience.  Another factor that affected the comfort rating was the crew.  Passengers prefer a young, enthusiastic crew and pilots that give clear and good information during the flight.

It is surprising to me that perception can affect comfort in such a dramatic way. With airlines trying to fill more seats on every flight, this might give passengers a new perspective on what airlines consider when designing and staffing their fleets.  Safe travels!



Mobile Robots Improve Hospital Logistics

By Cecilia Chan

As a high school student, I had two part-time hospital jobs: cafeteria worker and patient support worker. My job tasks included meal delivery/pickup, linen delivery, and patient or lab sample transport…so this piece of technology resonates with me. Continuing on the theme of robots changing lives, authors of a 2011 journal article in Industrial Robot summarized the many benefits of mobile robots in hospitals.

The TUG is a mobile robot developed by Aethon (Pittsburgh, PA) to address hospital logistics needs. It is designed to travel autonomously throughout a hospital to handle linen and meal delivery or pickup, and pharmacy or lab sample transport. Similar robots known as automated guided vehicles (AGVs) have long been in use by automotive manufacturers to deliver auto parts from the warehouse to the assembly line in an efficient and accurate manner.  The TUG system consists of a battery powered mobile drive and steer module, a control module, and a detachable load carrying module. Each drive unit is capable of moving loads up to 227 kg – great for reducing ergonomic risks associated with manual material handling!

As Rick Barker of Humantech recently blogged, “the number of people requiring nursing care is outpacing the number of nurses, and as our population ages, this rate will only increase.” Studies have shown that nurses spend as much as 30% of their time dealing with logistics, such as tracking supplies, lab results, and medications.  TUGs are currently used in over 100 hospitals nationwide. They have been credited with reducing medication delivery time and lab sample turnaround time by over 50% and reduced the number of drugs misdirected or lost in transit. The TUG system also improved delivery times on night and weekend shifts when manpower was limited. This technology is positively improving patient care by allowing nurses to devote more time to patient care while driving down hospital operating costs.



Field Workers: Where is the Best Location for Your Touchscreen or Laptop in Your Vehicle?

By Blake McGowan, CPE

A common concern among oil/gas or utility industry workers is: “Where is the best location for my touchscreen or laptop in my vehicle?”  With modern advances in Wi-Fi accessibility, many companies have equipped field workers with touchscreens or laptops in their vehicles to improve productivity and the flow of information from the field to the operation centers.

Typically, touchscreens or laptops are located to the right of the driver and mounted on a post between the instrument panel and passenger seat.  This location often results in back discomfort from sustained back twisting and shoulder discomfort from excessive reaching.

Recently, Dr. Richard Marklin and his team of research engineers at Marquette University, sponsored by the Electrical Power Research Institute, conducted a detailed biomechanical-kinematic (joint angles) and muscle activity (electromyography), performance, and preference analysis of the following four common touchscreen or laptop locations (Saginus et al., 2010):

  • A – Laptop located directly over the passenger seat
  • B – Laptop mounted on a post located between the instrument panel and passenger seat
  • C – Touchscreen mounted to the right of the steering wheel
  • D – Laptop mounted to the right of the steering wheel

Results of the detailed analysis found that locating the touchscreen or laptop closer to the steering wheel (Locations C and D) is best.  In these locations:

  • Kinematics improved as a result of reduced trunk rotation and shoulder angles.
  • Muscle activity was reduced for the spine and shoulder muscles.
  • Ease of use and productivity improved.

In addition, drivers preferred locations C and D.  Overall, getting the touchscreen or laptop closer to the steering wheel will improve the biomechanics of working inside a vehicle and will reduce the risk for musculoskeletal disorders.

Saginus, K.A., Marklin, R.W., Selley, P., Simoneau, G.G., and Freier, S. (2011). Biomechanical Effects of Mobile Computer Location in a Vehicle Cab:  Human Factors, 53 (5), 474-488.



New Blade Design Makes it Easy to Beat Those “Bad Vibes”

by Josh Kerst, CPE

Remember when the Beach Boys sang about those “Good Vibrations”?  Well here’s a dirty little secret…they lied!   Anyone who has cut lumber or plywood with a hand-held saw has firsthand experience with the fatiguing vibration and force requirements needed to get the job done right.  Traditional blades vibrate and can dull quickly adding to the force needed for the task which in turn requires the user to adopt a tighter grip during precision cutting tasks.   These tighter grips exacerbate the transmitted hand-arm vibration which can lead to irreversible occupational diseases such as Raynaud’s Phenomenon and Vibration White Finger syndrome.  Adding insult to injury these dull blades also extend the hand-to-tool contact time exposure which makes precision cuts extremely challenging and meeting hand-arm vibration exposure limits nearly impossible (e.g., vibration total value < 2.5 m/s2 for action limit and < 5.0 m/s2 for maximum exposure limit).

An innovative new blade plate design has been introduced by DeWalt within their Precision FramingTM line that promotes smoother,DeWalt Framing Blade less forceful cuts compared to traditional blades.  The new blade plates (see image) use a combination of high lubricity carbide coating on their blade teeth in conjunction with saw plates that feature resin filled expansion slots that help dampen vibration.  This ergonomic design shows promise in improving the cutting feel, lengthening blade life performance, and dampening vibration.  More detailed measurement will be needed to confirm this, but the design looks like a step in the right direction to losing those “Bad Vibes”.



Product Review: zeroG

Product Name:

zeroG® Mechanical Support Arm

Description:

For the past couple of years, Equipois Inc. has revolutionized the ergonomics world with its patented zeroG® mechanical support arm technology that has quickly found itself to be a highly beneficial resource in applications across multiple manufacturing zeroGenvironments.  These include but are not limited to: overhead sanding, component grinding, riveting, welding, drilling, and a range of other manufacturing processes.  The latest model, the Equipois X-Ar exoskeletal arm support is a wearable device designed for tasks where people work with their arms outstretched for long periods.

Ergonomic Benefits and Features:

  • Makes heavy tools, parts, and other loads almost negligible.
  • Extreme freedom of motion when manipulating the arm.
  • Simple to learn and intuitive to control.
  • Reduces forces placed on the upper body when working with outstretched arms or heavy objects.
  • Requires minimal maintenance and is easy to integrate into existing equipment as retrofits and/or add-ons.

Potential Limitations:

  • Requires adequate space to use device.
  • Not yet able to accommodate quick changes for various weight loads within task, however, settings are adjustable to any specific load.

Applications:

  • Aerospace
  • Automotive
  • Heavy Machinery/Equipment
  • Manufacturing
  • Doctors
  • Dentists
  • Drilling
  • Grinding
  • Riveting
  • Sanding
  • Welding

Humantech does not endorse any of the products or companies featured in the reviews. All images are property of the vendor and used for illustrative reference only.



How Do Your Rate Your Ergonomics Process?

by James Mallon, CPE

During my webinar last week, I asked the attendees three polling questions, and I think the responses were very telling as to the present state and future direction of ergonomics. The questions (and responses by percentage) were:

What is the primary function of ergonomics?

  • 54% – Reduction of WMSD (Work Related Musculoskeletal Disorders)
  • 29% – System Performancce
  • 2% – Return to Work for Injured Workers
  • 15% – Other

The majority of the 185 respondents view the primary function of ergonomics to be in the prevention of injury.  This is well placed, however, in my view, rather limiting.  If there were no WMSD injuries, would there be no need for ergonomics?  For me, the primary function of ergonomics is to optimize the performance of the human in a system.

Where does responsibility for your ergonomics process reside?

  • 15% – Ergonomics Group
  • 47% – Environmental Health and Safety
  • 11% – Operations
  • 14% – Human Resources
  • 5%  - Engineering
  • 10% – Other

Ergonomics still seems to be viewed as an EHS responsibility. Depending on how you add it up, 61% to 76% of respondents placed responsibility for ergonomics on EHS, Ergonomics, or Human Resources.  Putting ergonomics under EHS is akin to holding the dishwasher at a restaurant responsible for the amount of food being returned uneaten to the kitchen.  I think responsibility for bad workstation/job design (the root cause of ergonomic risk) rests with those who designed it – engineering/operations, which received only 16% in this poll.

At what level of maturity is your ergonomic process?

  • 2% – Ergo-What?
  • 37% – Reactive
  • 53% – Proactive
  • 8% – Advanced

A good finding – more than half of respondents (53%) consider their ergonomics process to be “proactive”.  But clearly there is still work to do, as almost 40% of respondents are “reactive” (or less mature) and only 8% would consider their process to be “advanced”.  An advanced process is the goal, as it means we are designing in ergonomics before products or workstations reach the plant floor.



Nine Tips for Workplace Improvement

By Christy Lotz, CPE

Being a blog reader, one of the first things I try to do when writing a post is to KEEP IT SHORT!  Reading epic blog posts that require 25 scrolls on my phone is not fun. Here are some quick tips for workplace improvement:

  1. Keep the wrists neutral – Neutral wrists provide the most strength and promote blood flow.
  2. Keep it in the comfort zone – The comfort zone (aka. the strike zone) includes the area above the knees and below the shoulders.
  3. Keep heavy and frequently-used products above the knees – Get those heavy parts off the floor or skids. Placing products just about the knees, although a baby step, can go a long way towards back health.
  4. Keep it in line with the spine – Eliminate twisting wherever possible.
  5. Keep it close – Keeping loads in close to your body is very important. The farther out your reach, it becomes exponentially worse on the shoulders and back.
  6. Avoid static hold of awkward postures – Holding poor postures or high forces for long periods of time is just as bad as repetition.
  7. Eliminate contact stress –  Removing pressure on soft body tissue will increase blood flow and and bring oxygen and nutrients to the muscles.
  8. Design for a seated or standing workstation – Just putting a chair at a standing workstation, does not make it a seated workstation! Design properly for one or the other.
  9. Decrease vibration exposure – Watch out for high vibration exposure as it can increase onset of musculoskeletal disorders such as white finger.

Can you think of a 10th to round out the list??



Ergonomics Tips for Lean Events: How Much is Too Little?

By Rick Barker, CPE

During a lean or continuous improvement event, teams often look for ways to reduce the footprint of a workstation. In some cases, this reduction is a measureable goal of the event. Less floor space means lower overhead cost. A smaller footprint can also benefit the employee by reducing the amount of reaching and walking. Although it’s generally a good idea to strive for a smaller workspace, the desire to reduce space can interfere with an operator’s ability to perform the task well and can introduce ergonomic risk factors. For instance, when working at an assembly bench, the operator needs sufficient free space on both sides to accommodate the width of his or her body (or the width of the part), plus sufficient space for arm and tool movements. This requires at least 46” of horizontal space, sometimes more when the part or tool is particularly large.

Other space considerations include:

  • Width of the walk space between machines and/or storage carts (48” minimum)
  • Knee well width (30” minimum) and depth (18” minimum) for seated tasks
  • Space to walk around to the sides of a pallet or box for loading (29” minimum)

Ergonomic design guidelines like these can help teams implement workplace modifications that correspond to human capabilities and limitations, simultaneously maximizing operator safety and productivity. Applying the guidelines during lean events will ensure that the improvements implemented are effective in meeting these goals.



Selecting the Right Casters for the Job

As an ergonomist, one of the most common questions I get asked is how to select the right casters and wheels for a specific job. Something as simple as the wrong wheel on a cart may turn into a source of high ergonomic risk exposure to the operator. Therefore, proper caster selection is essential. Here are some key features to consider when choosing casters:

Surface of the job. Whether it is an indoor environment (usually poured concrete) or outdoors (where surfaces vary from dirt roads to asphalt and grass) the appropriate type of wheel may change significantly, from solid urethane to air-filled rubber. The rougher the surface, the softer the wheel should be. However, the harder the wheel, the lower the force required to maneuver the cart. This implies a trade-off between wheel reliability and push/pull force requirements.

Weight of the job. Knowing the maximum weight you need to support will help determine the proper casters and wheels for the application. To minimize the pushing force, the minimum recommended caster diameter is 8″, and to maximize stability, the recommended caster width is 2.5″ to 3.0″. Casters should contain ball bearings to further reduce the required push forces.

Transport distance and location. A combination of straight and swivel casters should be used when steering in straight lines or around tight corners. For pulling applications, the swivel casters should be in front of the cart, and for pushing applications, the swivel casters should be in the back.  Locking mechanisms should be available to prevent runaways.

The proper casters will reduce the forces required to move the cart however, a properly designed cart is also essential to offer the operator a risk-controlled work environment. Cart features include:

  • Handles. Continuous vertical handles are best separated by 18″ maximum and 1.5″ in diameter, and 5″ long (5.5″ with gloves).  The height of the handles will be determined based on who will be maneuvering the cart, ranging from 36″ to 45″.
  • Size. The size of the cart will depend on the size and weight of the load to support and the space constraints of the environment.
  • Height Adjustability.  This is desired if manual transference of loads is required to/from the cart to various heights (e.g. conveyors, pallets, worktables).
  • Distance. Powered carts will relieve manual exertions during longer trips.



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