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An obstacle course at the University of Pittsburgh's Human Engineering and Research Laboratories tests wheelchair stability and the effects of bumps on wheelchair riders. (Graduate student Erik Wolf is pictured in the chair.) (Photo by Carl Bower)



Long-Term Wheelchair Use Leads to Stress Injuries in People With Disabilities

c.2000 Newhouse News

America's wheelchair users, confined to their seats with severed spines, limp legs and broken hips, are encountering a new set of modern maladies.

They are being hurt by the wheelchairs themselves.

Because of medical advances, many disabled people are living longer and getting around more. The population of wheelchair users outside nursing homes is climbing sharply, from about 720,000 in 1980 to an estimated 2.2 million today.

But the flip side of longer, more active and independent lives has become excruciating: torn shoulder muscles, pinched wrist nerves, wrenched backs and sores on legs and backsides.

"We're getting the consequences of aging," said Lucy Spruill of Pittsburgh, a 30-year wheelchair user whose ripped rotator cuffs left her temporarily unable to lift her arms. "This is what's happening to me instead of the hip replacement that my (able-bodied) friends are getting."

A cadre of doctors and engineers is dissecting the phenomenon, testing new theories about the human body, the wheelchair and the complex physiology of hand-to-wheel repetitive motions. Ideas are surfacing to prevent injuries, which cost millions of dollars and create new barriers to daily freedoms.

"I can hardly go a half a block because of the shape I'm in with my hand," said Melvin C. Braxton, 59, of Baltimore. A bone protrudes from the base of his sore left thumb, Braxton said, because he's been forced to push his Medicare-approved wheelchair at an awkward angle since he was paralyzed in a 1964 car accident.

More than 400,000 people in manual wheelchairs experience serious secondary injuries to their shoulders, wrists, backs and other body areas, according to leading researchers at the University of Pittsburgh.

Increasingly, blame is aimed at a health care system that has not kept pace with gains made by the disabled rights movement, researchers said. Some examples:

-- The modern inventory of wheelchairs could fill a new car showroom, but doctors typically aren't trained to prescribe the right chair for a particular illness, body type and lifestyle, researchers said.

-- Medicare and private insurance, meanwhile, routinely match patients to chairs that are less expensive in the short run, but too heavy and ill-fitting, causing health problems over time.

-- Patients rarely get enough instruction on wheelchair fundamentals -- axle, seat cushion and backrest adjustments, wheel stroke techniques and obstacle navigation.

Reform has lagged, advocates said, because expectations remain low for the disabled to thrive in mainstream life -- succeeding at work, raising families, traveling and participating in community activities.

For many, the disabled rightly deserve a wheelchair with reliable brakes and a pair of footrests. But the thinking often ends there, said Rory Cooper, director of the Human Engineering Research Laboratories at Pitt.

"Our society has basically said, `It doesn't matter. If you need a wheelchair, give up,"' Cooper said.

The wheelchair's plodding evolution tells much about the nation's awkward relationship with the disabled.

In the 1700s, wheelchairs were heavy and cumbersome, more like hospital equipment than mobility aids. A century later, the needs of thousands of Civil War amputees led to lighter wheelchairs, but those veterans were institutionalized. In another 80 years, soldiers injured in the early stages of World War II were issued those same Civil War wheelchairs.

Franklin D. Roosevelt, discontented with the clumsy chairs available during his presidency, preferred a kitchen chair fitted with wheels.

It took the innovations of wheelchair athletes of the 1970s, plus mandates in the decade-old Americans With Disabilities Act, before wheelchairs began to change significantly.

Bob Hall, the first wheelchair athlete to complete the Boston Marathon, recalls pulling apart one of the archaic chairs.

"It had stuff I did not need: armrests, push handles, brakes," said Hall, now president of Newhall's Wheels, a Cambridge, Mass., wheelchair manufacturer. "The stuff that was in the way, I threw out."

Hall later created a chair from scratch. With a lighter, simpler frame and wheels angled for stability, it was coveted by other riders stuck in standard, clunky chairs.

"As users, we want to look cool and get there sooner than later, and feel good about ourselves," Hall said.

Today's wheelchair inventory still includes plenty of the old standard model, known as the "depot." With a chrome skeleton and vinyl seat, the 50-pounder has changed little since it was invented in 1932 by a pair of mining engineers.

Next up the hierarchy are lightweight chairs. Weighing between 25 and 40 pounds, the steel or aluminum lightweights offer modest adjustments, such as movable armrests.

At the top end of the market are ultralights, which may weigh as little as 15 pounds. A user who can afford one gets a chair with an adjustable axle, seat, backrest and more.

But the old depot remains a standard in hospital corridors and medical supply stores. About six in 10 American wheelchair users ride in a depot, Cooper said.

Economics is a big factor. While the better chairs may cost $2,000 or more, a foldable depot is available for $200 or so.

The low price is attractive to many insurers. But researchers argue that the inexpensive chairs actually cost more over time because they wear out in only a year or two. More important, their weight and lack of adjustability are blamed for injuries.

In one familiar scenario, a chair that's too heavy and badly fitted might gradually cause rotator cuff damage so severe that shoulder repairs are needed. Surgery and rehabilitation might cost $100,000.

"That's a lot of wheelchair," said Dr. Michael Boninger, the Human Engineering and Research Laboratories medical director.

Research has revealed a variety of risks associated with wheelchairs.

At least 50,000 U.S. wheelchair riders require emergency room treatment each year, according to research. Most are hurt in "tip and fall" accidents.

Of those, about 50 die annually, said Dr. Lee Kirby, professor of physical medicine and rehabilitation at Dalhousie University in Halifax, Nova Scotia. Most succumb to head injuries.

"It's all too common we see people in a dangerous chair," Kirby said. "But I also feel it's not only picking the right chair, it's training people to use the chair in an environment that makes sense. We don't train them on curbs, or grass or gravel, or sidewalks that have heaved a little."

More than half of today's wheelchair users suffer chronic injuries from long-term wheelchair use, Boninger said. Rotator cuff and carpal tunnel problems are most common, he said.

Such circumstances were rare before medical advances extended the life expectancies of people with spinal cord injuries and many diseases.

"Before World War II, if you got a spinal injury, you died," Boninger said. "It might have taken you a couple of years, but you probably died of renal failure. In developing countries, you still die. But this is new, people being in wheelchairs for 30 or 40 years."

The Pitt research lab, housed at the Veterans Administration Pittsburgh Health Care Center, is widely known for its secondary injuries studies. In the cinder-block rooms, which hold an eclectic collection of equipment ranging from soldering guns to blank-faced manikins, researchers have launched groundbreaking tests of machines and bodies.

To test how wheelchairs hold up in weather, they are placed in a giant box that gets as hot as 160 degrees and as cold as 40 below zero. The chairs are run through an obstacle course to measure maneuverability and perched on rolling drums that simulate bumping over a tree root or sidewalk crack 800,000 times.

In one test, a chair is rolled up a ramp to measure the angle at which it will tip over backward. That particular test requires the wheelchair to be occupied, by either a dummy or a graduate student, Cooper said.

More complex tests are used to check humans who are developing secondary problems.

In one test, a patient's seating is evaluated by a device that uses sensors to measure pressure on thighs and buttocks. Seating angles and cushions can be changed to avoid sores.

In another, a patient pushes a stationary wheelchair while computers measure the complicated mix of muscle forces and body geometry. A sensor on the wheel computes how hard a patient works each joint. Meanwhile, to record body mechanics, special cameras follow 22 dime-sized infrared sensors attached to a patient's arms, legs and torso. On a nearby computer monitor, the sensors are depicted on a blank background; the wheelchair rider looks like a constellation in motion.

Researchers can pinpoint many problems through such tests. A patient's hand stroke may be too short or too forceful. His torso may lean too far forward, his hand may twist inward, the chair's push rim may be too narrow or the wheel position may require a backward reach.

Spruill, a patient at the Pittsburgh clinic who has spina bifida, had to switch to an electric chair because her rotator cuff damage was so severe. Shoulder pain overtook her gradually as she spent years in a manual wheelchair that was too heavy and poorly fitted.

"I couldn't concentrate on a TV program, on a book, on my work," Spruill said, recalling the discomfort. "I couldn't enjoy fun things with my friends. There was a time when I realized I hadn't enjoyed a balanced meal in months. I would just come home and eat something cold or heat something up."

The rotator cuff refers to the four muscles that allow the shoulder to rotate and provide stability to the arm. Attached to bone by a common tendon, the structure also helps keep the upper arm bone from sliding out of place.

Through overuse or improper biomechanics, the rotator cuff may become inflamed and tear.

"For a pitcher," Boninger said, "it may be career-ending. For a wheelchair user, it may be the loss of independence."

Carpal tunnel syndrome, meanwhile, is a wrist problem better understood in recent years because thousands of computer keyboard users have reported discomfort in their fingers, hands and wrists.

It occurs with overuse and strain. The median nerve, which extends down the arm, passes through the wrist between bones and ligament. Pressure increases on the nerve when it becomes inflamed. Results include tingling, pain and clumsiness.

Such symptoms, whether they appear in the hands or elsewhere, are the kinds of warnings that terrify disabled people who rely so completely on their arms.

Christopher Curtis, 42, of Baltimore, a quadriplegic with some use of his arms and hands, recently fought off a bout of elbow pain. He said any surgery would "stop my life." Rehabilitation would mean hiring someone to help him get out of bed and complete other basic tasks.

"Knowing that those (secondary injuries) are out there, any twinge is like getting caught in the headlights of a car," Curtis said. "You go, `Oh, no!' When it goes away, you say, `Whew."'

Barbara Ruggles, 48, of Cincinnati, was paralyzed in a 1971 car accident. Active in wheelchair sports and other activities for years, she developed the numbness that signals carpal tunnel syndrome.

The pain began in 1984. Surgery on her left wrist came seven years later.

"I controlled it with anti-inflammatory medicine," Ruggles said. "You just learn to cope. Since I depend on my hands for everyday living activities, for eating and getting dressed, it was a real big scare. I think it would have helped to have a lighter chair from the beginning, or an electric chair."

A better chair would have eased the most exhausting days, the trips to the zoo or amusement parks, when she sometimes pushed her heavy wheels for hours.

Today, further wrist problems have forced Ruggles into an electric chair. It's a permanent change.

"I really miss the sports activities," she said. "I used to go on camping vacations, white-water rafting. But I can't do it anymore. I don't have any strength."

An antidote to secondary injuries will be difficult. The population of wheelchair users will grow. They will live longer. And there is no swelling movement to reform insurance reimbursements that match patients with the cheapest chairs.

Mary Rodgers, chairwoman of the Department of Physical Therapy at the University of Maryland School of Medicine, said an ongoing study suggests that exercise can prevent secondary problems.

Exercising with large rubber bands to stretch and grow stronger, study subjects are showing less strain on muscles and tendons. What's unknown is whether the regimen will work over time.

"There's a real need for long-term types of studies," Rodgers said.

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