Innovative Crutch Designs: More Gain, Much Less Pain
April 2008 Issue
|Photographs courtesy of Thomas Fetterman.|
Although ambulating with crutches would probably not rank on anyone's A-list of favorite activities, it can solve the problem of mobility after injury. Crutches have a long history. Evidence from an Egyptian carving dating back to 2830 BC suggests that crutches have been used at least since the pharaohs ruled Egypt 5,000 years ago. Through the corridors of time crutch design has not greatly changed. However, some modern inventor's have set out to change that scenario developing innovative twists on this age-old solution.
Like many innovations in the rehabilitation field, several new crutch designs have been sparked by their inventors necessity and dissatisfaction with what was already out there, while others have been inspired by a fascination with high-tech materials.
'Vertical into the Future'
At age eight, Thomas Fetterman fell victim to the polio epidemic that swept the country in the 1950s. He developed inflamed shoulder joints in the 1980s due to the impact of constant crutch use. "My doctor just told me to slow down and take aspirin," he recalls.
Two negative aspects to using crutches, according to Fetterman, are slipping and falling on slick or uneven surfaces, and the harmful effects of long-term crutch use on cartilage, bone, tendons, and nerves. "The single most important aspect of any crutch or cane is the way it engages the ground. If you don't get that part right, the crutch or cane wont be of much value."
Fetterman knew what was needed: greater ground-grabbing ability plus shock absorption. He developed and patented a crutch tip with a shock-absorbing gel system, and in 1988 began manufacturing and selling the tips. Today, Thomas Fetterman Inc., Southampton, Pennsylvania, provides a variety of crutches, canes, tips, and crutch accessories.
The Smithsonian Institute chose Fetterman's Litestix titanium forearm crutch as part of its exhibit, "History of Polio," to show the technical advances in crutch design and materials.
Fetterman crutches are custom-made to fit a customer's exact needs. Since they are custom-made, there are no adjustment holes to start to wear, "egg out," and start clicking and clattering, he notes.
|Photographs courtesy of Keen Mobility|
While Fetterman uses the forearm crutch, which is the preferred design in Europe and much of the rest of the world, axillary (underarm) crutches have been more commonly used in the United States. "Various studies plus my own experience shows that the forearm crutch is less deleterious to the body and a better solution for long-term crutch users. Its convenient in other ways as well-its shorter and fits in the overhead bin of an airplane. And you can store them under the table in a restaurant without tripping too many waiters," he adds with a chuckle.
Fetterman believes that people in the United States prefer axillary crutches because, to many people, they indicate a temporary impairment. Forearm crutches, on the other hand, connote permanent disability. However, forearm crutches got a boost in 1997 when then-President Bill Clinton selected a pair of snazzy black Superlites after tearing his right quadriceps tendon. He called the Superlites his "Stealth" crutches. In a news conference, Clinton said, "I think they were developed as an offshoot of B-2 technology... I like them quite a lot."
"After that, my sales doubled," Fetterman says.
'Moving Beyond Our Own Boundaries'
Vail Horton, co-founder and CEO of Keen Mobility Inc., Portland, Oregon, was born without legs or a fully developed right hand. Doctors told his parents he would likely never walk. Not willing to accept this prognosis, Vails grandparents sent the youngster to the Rusk Institute of Rehabilitation Medicine in New York, New York, which met the challenge and fitted him with prostheses and provided crutches.
However, as a 19-year-old college student, he started suffering from osteoarthritis in his shoulder and carpal tunnel syndrome in his hands due to the stiffness of the devices. Doctors told him he needed a wheelchair. "I asked myself, 'Why couldn't I put a shock absorber in a crutch?'" With a team of other students from several disciplines, including engineering, life science, and business, Horton went to work developing a new type of crutch with shock absorption.
The company was launched in 2002 and named after Horton's grandfather, Kelvin Keen; it now produces about 35 types of assistive devices.
|Photographs courtesy of Lance Matthews.|
The company's Navigator™ crutch features a solid-core polymer shock system to help prevent shoulder osteoarthritis and to reduce stress on the back, shoulder, wrist, and elbow. The polyurethane tube expands and contracts as the crutch strikes the ground, absorbing and dissipating the force. The tip "grabs the ground really, really well," says Horton. "We've given the [pivoting Adventure™] tip almost an entire ankle, so there's 100-percent ground contact even at a 30-degree angle." The contoured underarm support is designed to increase blood circulation, reduce numbness and risk to the nervous system, and also to help prevent shoulder osteoarthritis. The company has recently introduced a forearm crutch with similar features.
In 1997 Lance Matthews, an inventor, carpenter, and organic farmer in Ontario, Canada, fell off a two-story building and fractured his leg. "There I was, on crutches, unable to do anything," he recalls. "My leg was holding me hostage." After a few frustrating days, he decided there had to be something better.
"I went to my workshop, and in about 15 to 20 minutes I was able to get a stick, put a shelf on it, and thus make a rudimentary prototype. I put my knee on it, holding it with one hand; now I could walk around holding a cup of coffee." Matthews realized that if he used a Velcro® strap or a couple of leather belts to fasten the device to his leg, he could have both hands free. "With this basic prototype I could go up and down stairs and do my work."
This simple design became the iWALKFree™ crutch, which Matthews notes is especially beneficial for active people and those who have to get back to work as soon as possible. The device incorporates extruded aluminum and engineering thermoplastic for lightness and strength.
Matthews doctors and orthopedic technologists at the Sunnybrook and Women's College Health Sciences Centre in Toronto, Ontario (the Sunnybrook Health Sciences Centre and Women's College Hospital separated in April 2006), were so impressed with the device that they initiated a preliminary clinical trial with positive results, which were presented at the Canadian Orthopaedic Association's Annual General Meeting in Edmonton, Alberta, in 2000.
A study, "The Use of a Hands-Free Crutch in Patients with Musculoskeletal Injuries," by Rohit Rambani, et al., reported in the International Journal of Rehabilitation Research , December 2007, notes the value of the iWALKFree in enabling patients to have shorter hospital stays and become independent quickly. The authors observe that further research is needed to define the appropriate range of injuries for use of the device and to study the effects of long-term use on soft tissue, along with energy expenditure and gait analysis.
Grad Student's Creative Design
The S_UPPORT is the result of a graduate student project by Taiwanese medical designer Pei-Hua Huang, who currently lives in the United States. The device, made from recyclable nano-nylon, features a modular design. With exchangeable parts and accessories, the crutch can be adapted to each users needs, Huang points out.
Huang explains, "They say, 'Form follows function', but in this case, it was 'Form follows material.'"
|S_UPPORT short-term use plastic crutch. Photographs courtesy of Pei-Hua Huang.|
An S-shaped design developed by the Massachusetts Institute of Technology (MIT) with carbon fiber impressed upon him the importance of flexibility. "I believe flexibility comes from two directions: shape and material," says Huang. The Nike Shox design gave him another hint: "What if I apply flexible foam rubber with the S-shape design?" With exchangeable parts and a lower price, it could be a competitive, innovative crutch for short-term use, Huang decided.
Are You an Inventor?
Have you found a solution for a mobility or related problem you have? Just as these innovators have found, your idea could be profitable for you and beneficial for others. As Matthews points out, "If you've solved a problem, there are probably lots of other people with the same problem."
Miki Fairley is a contributing editor for The O&P EDGE and a freelance writer based in southwest Colorado. She can be contacted via e-mail at firstname.lastname@example.org
Editor's note: The O&P EDGE does not endorse any company or product. Companies and products mentioned in this article are for reader information only as a representative sample of the crutch systems and accessories available.