Wednesday, January 28, 2009

"No pain ... no pain"

Tuesday's membership meeting featured an informative lecture from SHELBY CASS, animation ergonomics expert, with simple and effective advice for keeping ourselves healthy and our workspaces optimized.

Shelby was instrumental in devising the Educational Ergonomics program at Pixar, reversing the trend of RSI (repetitive strain injury) problems at that studio. She has also consulted for DNA Productions, KeyOvation (Goldtouch), Wacom, ILM, Apple, Blue Sky, WETA, and Henson, and is currently working at Yahoo! while additionally operating her own Northern California ergonomic consultation business.

She described ergonomics as the science of:

  1. how you work
  2. how you could work better
  3. why you don't do that by default

Replacing and adjusting equipment is easier and cheaper than replacing body parts (unfortunately, this is something that sounds glib until our pain has become chronic). RSI risk is very high for those working in an awkward position (e.g., in front of a desktop computer or a drawing table) for more than four cumulative hours per day.

Using a laptop computer puts you at high risk after just two cumulative hours per day. Why are laptops more risky? Because the monitor, keyboard and trackpad are attached to each other and cannot be adjusted to optimum heights and angles. Shelby recommended an external keyboard and mouse and propping the laptop up to eye level if you use a laptop regularly at a workstation or at home.

The risk factors for RSI are:

1. Awkward posture.

2. Repetition.

3. Forceful exertion. Note that 'forceful exertion' doesn't mean high levels of force, like lifting heavy boxes. It means any exertion that requires force, and could be as simple as pinching a mouse or leaning against something.

RSIs occur when the body hasn't had enough time to heal after repeated trauma. Numbness and tingling are signs of restricted blood flow and nerve impingement -- these are signs that should never be ignored.

Shelby gave the members a lesson in "neutral posture" and correct sitting. Neutral posture has similar elements whether one is sitting or standing:

The ears are above the shoulders.

The shoulders are over the hips.

The elbows are directly under the shoulders.

Most of us don't sit that way, but the strain on our bodies is greatly reduced by following those simple guidelines. Other good rules for sitting properly:

  • Hips should be as far back in the chair as possible.
  • Feet should be planted firmly on the floor.
  • Knees should be at the same level as the hips, or slightly below.
  • There should be two or three fingers of space between the front of the seat pan and the back of the leg.

Your chair* should offer:

  • Adjustable lumbar height;
  • Independent adjustability of seat and back;
  • Elbow clearance and sidearm adjustment.

When sitting at your workstation, your elbow should be bent at a 90-degree angle or greater, your shoulders completely relaxed, and your forearms should be parallel to the floor. To achieve this, sit in your chair as described above and have someone measure from the tip of your elbow to the floor. Subtract one inch for the height of you keyboard; the result should be the height of your work surface.

Your computer monitor should be just high enough that you can view it without having to raise or lower your head. Sitting in the optimum position as described above, hold a pen pointing out from your forehead between your eyes. Have someone measure from the tip of the pen to the floor, and subtract the height of the work surface. The upper edge of your monitor's viewing screen should be that far from the work surface.

More of Shelby's suggestions:

  • The eyes are the most powerful postural dictators. Our body always tends to go in the direction we're looking, so if your monitor(s) or work surface are poorly located, you will get neck/shoulder/back strain.
  • "No reaching" for regularly used items. Pencils, coffee, phone, etc should all be within a three-inch radius of each forearm.
  • Shelby recommends shorter keyboards for artists, few of whom need a keyboard with a number pad. This keeps keyboard where it should be and the mouse/trackball/Wacom tablet close at hand.**
  • She recommends that right-handers use the mouse with their left hands to the left of the keyboard. Practice "straight-wrist mousing" with the hand over the mouse.
  • Cintiqs should be on an adjustable surface. If you're stuck having to use a workstation for both Cintiq work and keyboarding, and/or multiple monitors, be careful that the workspace is set up to maximize use of the equipment you use the most.
  • Be good to yourself. Get up often; stretch, breathe and relax, and drink lots of water.

Shelby's lecture gave us all a lot to think about in terms of how we interact with our workspaces and our equipment. Check out her website for more valuable information or to contact her directly.

*Shelby is a fan of Soma chairs, but cautioned that there's no perfect chair for everyone.

**She mentioned some CG animators have successfully and happily replaced their keyboards with X-Keys. She also mentioned the Goldtouch keyboard as a good alternative to the usual clunky keyboard.


Anonymous said...

Thanks for posting this. I just recently noticed a numbness in my ring finger on my right hand, most likely from my forearm resting on the corner of my desk for 12-16 hours a day (yay crunch!) and pinching the nerve...

Anonymous said...

Injuries of this nature are no joke. I developed tendinitis in my elbow from long hours of mouse usage, and it's taken 2 years of medical procedures and physical therapy to get back most of the proper functioning in my arm and wrist. Believe me, if you don't have it, you don't want it.

The tip about using the mouse with your non-dominant hand is gold. I switched after my surgery, and I'll never go back.

smac said...

It was a pleasure meeting with and talking to you. Thanks for having me! Do take care of yourselves.

erin said...

Shelby, come to SC for a visit so you can look at my workstation!!!

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