There’s a nationwide epidemic of pen obesity, and that’s a good thing. Over the past decade, the size of pen barrels has been growing. Many are now twice as large as traditional ballpoint pens. The reason? Ergonomics.
With the rise in repetitive stress injuries, researchers have made great strides in ergonomics, also known as human engineering, an applied science of designing objects to be more comfortable, efficient and safe for people to use.
Millions of people who suffer from hand problems, such as arthritis, carpal tunnel syndrome, repetitive stress injury from computer keyboards and “ballpoint pen tenosynovitis” — plain old writer’s cramp — welcome these oversized pens, a result of the new research.
“If you increase the area, you will decrease the pressure,” says Doreen Stiskal, a professor of kinesiology at Seton Hall University who researches grip. It’s a basic principle of physics: pressure equals force divided by surface area.
Fat pens reduce gripping pressure, and less gripping pressure reduces hand stress and fatigue.
“Think about a 3- or 4-year-old child who does not have a lot of grip strength yet. We give them large crayons or markers, things that have a wider circumference because they don’t have to use as much muscle power,” Stiskal says.
“A wide pen helps us biomechanically. We don’t have to pinch so much and we don’t need to recruit as many motor units, or fine muscles that fatigue more quickly,” she says. The act of writing affects muscles not only in the hand, but the neck, shoulders and arm.
There are now dozens of varieties of wide-bodied pens, pencils and markers available among the 8.8 billion sold in the $3 billion-a-year writing instrument industry, according to the Writing Instrument Manufacturers Association, an industry trade group.
The Dr. Grip pen made by Pilot Pen Corp. of America is one of the most popular, selling about 10 million a year, says Robert Silberman, director of marketing for Pilot.
The original Dr. Grip was designed in Japan by Dr. Hiroshi Udo, a physician who wanted to make a more comfortable pen for his patients who suffered from repetitive stress problems and arthritis. Pilot debuted it in the United States in 1995
“There were a lot of people who couldn’t write for years until they bought this pen. At that time there was really nothing like it in the marketplace,” says Silberman.
Besides diameter, there are other features to consider in a pen, such as weight, length and grip, says Leighton Davies-Smith, director of writing systems for Sanford Corp., maker of Paper Mate products.
Comfortable pens tend to be heavier, particularly at the tip, than slimmer pens, Davies-Smith says. Pens that are too short, too long or too hard tend to be uncomfortable. And research has shown that soft, squeezable grips feel better and dissipate gripping force better than hard plastic pens.
The PhD pen by Paper Mate features a soft, triangular grip that guides fingers into a more ergonomic position.
But there are limits to how wide pen diameters can be, Davies-Smith says. “Obviously if it’s too thick it gets too uncomfortable for women to hold because they have smaller hands,” he says.
Wendy Solomon writes for the Allentown, Pa., Morning Call, a Tribune Co. newspaper.
