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Practical Ergonomics 

Ergonomics: Helping Companies to Grow, While Protecting Employees
A Sports Medicine Approach to Overuse Injuries in the Workplace
Of Mice and Men: ErgoTips for the Desk Jockey
Donít forget your feet!
Pearls for safe lifting

Ergonomics: Helping Companies to Grow, While Protecting Employees

by 

Jeffrey Pearson, D.O.

[Originally published in the San Diego Business Journal, January 13,1997]

Put aside the notion that workplace ergonomics is only about injuries - it makes good business sense, as well.

"The fact is," according to Franz Schneider, "that healthy people work better and sick people perform poorly." Schneider is the president of Humantech, a Michigan-based ergonomics and consulting firm. "With all of the billions of dollars that are invested annually to improve employee health - smoking cessation classes, employee fitness areas, stress management, nutritionally balanced menus in the cafeterias, and the like - it is ironic how little consideration the physical workplace has received."

This may soon change with the recent adoption of the Repetitive Motion Injuries (RMI) Standard, by the California Safety and Health Standards Board.

Speaking recently at the National Ergonomics Conference and Exposition, in Los Angeles, Schneider plead the case that companies actually become more productive and profitable when they pay appropriate attention to ergonomics. Citing his firmís experience working with Fortune 500 companies such as Hewlett Packard, an ergonomically sound workplace also benefits the most important assets of any business - the employees. By encouraging a safe and work-friendly environment, employees recognize that they are valued and remain happy, and relatively injury-free.

"Sports medicine physicians know all too well just how difficult it is to win the Superbowl with a team of injured athletes." Continuing the analogy, Schneider noted that the quality of the physical work environment is analogous to an athleteís running shoes. "If the shoes fit the athlete and are correct for the sport, they will enhance the athleteís performance; however, if they are the wrong size or donít fit the requirements of the sport, performance may be reduced. In the short term, the wrong shoes may be a hassle or contribute to pain, but the long term effects may result in foot deformities."

Just as itís difficult to run a marathon in a pair of golf shoes that are three sizes too small, you canít hope to achieve world-class performance in an ergonomically poor workplace that doesnít support your performance needs. Studies have demonstrated how the design of office furnishings, seating, equipment, and workplace all interact to support or hinder productivity.

Unfortunately, many companies wait until an employee develops a cumulative trauma disorder (CTD), and then try dealing with the problem. Schneider notes that "managing CTDís is like managing customer rejects - youíre focusing on the problem very late in the chain of the events, similar to steering a boat by looking at its wake."

Itís been too easy for employers to ignore the business implications of workplace ergonomics in the past, because traditionally it has been difficult to quantify.

He suggests that a company establish goals and measure every element of human performance. Citing the Hewlett Packard credo "That which gets measured gets done," if an element of performance is measured, then management will attend to it.

Also commonly referred to as to repetitive stress injuries (RSIís), the true incidence and costs attributed to CTDís is not known, and is undoubtedly underreported. In 1994, CTDNews surveyed 3000 employers and reported that North American businesses spent nearly $4000 for every reported CTD case. In all, U.S. businesses paid about $3.6 billion in direct Workersí Compensation benefits for injuries such as carpal tunnel syndrome, shoulder tendonitis, and back strains.

These figures do not account for indirect costs, according to the North American Ergonomics Resources Guide, an industry publication. Indirect costs include overtime, employee retraining and production losses incurred as a result of injured workers. The Guide conservatively estimates that the financial impact of CTDís triples to about 10.8 billion or about $12,000 per CTD case.

Therefore, practicing proper ergonomics, as an integral part of the production process, will save significant amounts of money wasted on the treatment of avoidable CTDís, further enhancing a companyís bottom line. Simply moving objects to within an easier reach may save time and can minimize the repetitive stresses placed on the worker.

In summary, employers shouldnít perceive the new RMI standards as a hassle or a threat to their survival. Rather, they should consider the proven benefits of ergonomics in the workplace and watch their bottom lines improve. And, at the same time they will be protecting their most important resources - their employees.

A Sports Medicine Approach 

to 

Overuse Injuries in the Workplace

by

Jeffrey Pearson, D.O.

Recalling the fact that humans are living machines makes it easier to understand the mechanisms of injury in overuse conditions. There is an elaborate network of pulleys designed to move the various parts of our skeleton framework.

In actuality, these pulleys are comprised of two integral parts: muscle and tendon tissues. While the muscles contract to initiate movements, they would exert no effects without the tendons required to attach them to the bones. The muscles need to have elastic qualities in order to contract and relax. Tendons, on the other hand, generally remain unyielding in order to transmit the forces across the joints, inducing movement. In other words, muscle stretches like a rubber band; tendons behave like paper tape and do not lengthen unless they begin to tear.

When dealing with cumulative trauma types of overuse, the tendons incur microscopic connective tissue fiber tears at points of stress. One such point is their bony origin attachment. The best example of this is probably lateral epicondylitis - more commonly referred to as "tennis elbow." In this condition, the point of maximum tenderness is where the tendon for the wrist extensor muscle group (top of the proximal forearm) originates off of the lateral epicondyle of the elbow. (Incidentally, unloading the pressure off of this bony origin can help to prevent/worsen injury, hence the rationale for the use of counterforce, or "tennis elbow," bracing.)

It had been long thought that inflammation ("-itis") played a major role in the discomforts associated with overuse injuries, e.g. tendonitis. However, while it often accompanies injuries, there are overuse conditions in which no inflammation was detected in biopsy studies. Hence, physicians may refer to some of these problems as overuse tendinosis.

It should be noted that there are many factors affecting the degree of force placed upon these tissues. These variables include the intensity and duration of activity, inherent flexibility of the tissues and allowance of adequate recovery time (for the fibers to heal themselves), as well as the myriad of ergonomic issues (workstation design, activity technique, etc.). Addressing each of these is a prerequisite for the treatment and prevention of overuse injuries.

Sports medicine physicians grade overuse injuries based upon the symptoms and impact upon the athletes performance. This grading helps to guide the treatment and rehabilitation process.

Grade 1 No pain with activity, but some discomforts afterwards (either immediately or during the evening/following days).

Grade 2 Some discomfort with activity but does not interfere with performance.

Grade 3 Discomfort with activity and interferes with performance (body mechanics altered).

Grade 4 Discomforts so intense that activity cannot be performed at all.

Treatment Guidelines:

Grade 1 Usually reducing the intensity or duration of the activity by 25% is all that's required. Activity can be gradually increased as symptoms allow. A runner, for example, should never increase his or her weekly mileage by more than 10%. Similarly, an assembly line worker should gradually increase his or her production to avoid re-injury. Sudden, excessive overtime is a sure-fire recipe for overuse complaints because the workers do not have an opportunity to build up their endurance prior to the extra work.

Grade 2 Reduce intensity or duration of the activity by 50%.In addition to ice and stretches, consider the use of non-steroidal anti-inflammatory agents in appropriate individuals. Physical therapy can be considered, but is not absolutely necessary at this point. When pain is gone, have therapist teach an endurance program, in addition to concentrating on eccentric strengthening exercises.

Grade 3 "Active" rest: the worker should stop performing the offending tasks, but is allowed to move the affected part for his daily activities. Physical therapy is used to speed resolution of the discomforts, as well as rehabilitate, i.e. strengthen, increase endurance, restore coordination and proprioception. In addition to the oral non-steroidal anti-inflammatory agents, a corcoteroid injection may be considered at this time.

Grade 4 Complete rest of the affected part, usually involving the use of some sort of sling or splint (even casting is considered in severe cases). All of the above options applicable here. If worker fails to improve, or condition recurs despite adequate treatment, then surgical intervention may be required, e.g. removal of subacromial spur affecting a rotator cuff tendonitis.

Primary Prevention Tips: Unlike sports, there is no "off-season" for workers to recover from a season of overuse, nor is there a "pre-season" to warm up prior to beginning employment. Industrial athletes perform all year round. Therefore, it is extremely important to emphasize a continued flexibility program; otherwise, the tissues will be "tight" with reduced flexibility which will make it easier for the microscopic tears to occur, leading to injury. Only after the tissues have achieved a certain degree of flexibility should a strength training and endurance program be initiated. Starting strength exercises too soon will often result in worsening of the condition.

computer mouseOf Mice and Men: 

ErgoTips for the Desk Jockey

 

Regarding your posture, there is no optimal position, but the following guidelines will help the body to adjust better to fit a particular situation:

Adjust the chair first, the keyboard second, and then the monitor. 

Traditionally, ergonomists have advised:

Your feet should be flat on the floor.Poor sitting posture

Knees bent at about 90į.

The seat of your chair should be flat. The back of the chair should be straight upright (rather than leaning backwards) and the lower back should be supported.

Avoid sitting in positions that place sharp pressure on your legs or wrists. There should be at least 2 fingers clearance between the front edge of the chair and the back of the knee. Arm and shoulder muscles should be relaxed.Proper sitting posture 

Your elbows should be bent at about 90į, wrists should be straight, rather than cocked up or bent downwards.

If you use a monitor a lot, it should be placed directly in front of you. The top of your monitor screen should be slightly (e.g. 20į) below eye level. If you wear bi-focals, try tilting the lowered screen to lessen neck strain.

***More recently, the traditional views of sitting have been challenged and some alternative sitting postures discussed in The Chair : Rethinking Culture, Body, and Design by Galen Cranz[Some excellent reviews of the book can be found at the Amazon.com site here.] Feel free to experiment to see what works best for your body e.g. some people may find "perching" postures more acceptable via the use of sit-stand chairs. Other new and exciting chair designs include saddle-shaped seating such as the Capisco, the Bambach, and the Salli. (Beware the sticker shock factor, though!).

Other considerations:

Try taking a break from computer activities at least every 20-30 minutes. Getting up and moving around is ideal; try to break up computer tasks with alternate work [In fact, many of us would comment that getting up from chair as often as possible is much more important than worrying about the type of chair that one sits in.]

Avoid over-reaching and awkward positions. Things that you use most of the time should be within one forearmís reach, e.g. keep the mouse close to the keyboard and move your entire hand. Things that you use less frequently should be within a full armís reach, and those that you hardly ever use should be out of the way.

Use document holders and telephone headsets to maintain your neck in a neutral, i.e. stress-free, posture. The prices of good telephone headsets (e.g. Plantronics) are coming down. (If you're an employer, it's certainly worth springing for headsets for your staff as they're infinitely cheaper in the long run than a Workers Comp claim for a chronic tension neck syndrome!)

Reduce/eliminate glare by adjusting the monitor location, closing blinds, using focused light sources, or trying non-glare screens.

Ergonomic book, software, and website recommended by Dr. Pearson:

Working Well...? How to Correct the Unhealthy Workplace: The Ergonomic Approach. Terry McShane, M.A. T&M Associates, P.O. Box 23-2156, Encinitas, CA  92023-2156; (858) 753-6556;

Ergosentry (now includes Ergo Stretch, too!). http://www.magnitude.com/main/products.html

ErgoWeb. A great resource site for all things ergonomic. http://www.ergoweb.com

Donít forget your feet!conductor standing

Working on your feet all day can also lead to RSIís. For example, hard concrete surfaces do not absorb the forces from the striking of the foot against it. Rather, these forces are re-directed back upward into our bodies. These may result in continued stresses leading to micro-tears in the tissues of the arches of the feet (Plantar fasciitis), as well as chronic back fatigue.

Prevention is easy. Providing a means of dampening the forces between the ground and your feet makes sense. Vibram-soled shoes, such as those found in work/hiking boots are effective. I personally recommend Rockport  and Ecco's - they are extremely comfortable and lightweight, yet durable. (I also like Spenco shoe inserts  and my $9.99 Dr. Scholl's arch supports for additional shock absorption in my running shoes.) Shock mats are recommended for prolonged working in one place.

Pearls for safe lifting

THINK before lifting!   THINK before lifting!   THINK before lifting!  

  • Be familiar with what you're about to lift.  Don't just go ahead and assume that an object is either heavy or light. Test it gently, first - no one likes surprises!
  • Know where the object(s) needs to be placed.  Don't pick up and carry a box while you decide where it should go.  At the same time, be sure that you have a clear path to your destination, avoiding wet floors and junk that you might trip on.
  • Ask for assistance.  Don't hesitate to request additional help if an object is perceived as being either too heavy or awkward for one person to lift/carry in a safe manner.

Lift/carry using proper techniques

  • Keep your chin up while lifting and setting objects down. This helps to engage your legs and spares your back! Also, never keep your knees locked straight while forward Comparison of lifting techniquesbending - this places too much stress on the low back and can cause "locking" of the sacroiliac joints (this hurts!). Therefore, always try to partially bend at least one knee while bending - you'll notice the difference.
  • Carry objects as close to your chest as possible to decrease the forces placed upon the spine.
  • Don't twist while carrying.  The lower back (lumbar spine) is not designed for twisting.  Pivot, if you must turn.
  • If given the choice, it's better to push a heavy load than to pull it.  Simple physics dictate this, so why mess with Mother Nature?

Finally...

If you recognize that, despite your best intentions, you've still managed to overdo your lifting, don't wait for the symptoms of pain and stiffness to begin later on.  Apply ice/cold packs to the region as soon as possible for about 20-30 minutes.  This can often head off a painful low back syndrome 1-2 days later. Don't forget: ice is nice!