On Your Mark

The Paralympic Games put on display extraordinary feats of athletes, drawing attention to new advances in engineering and technology. According to sources interviewed for this Cover Story, the sports world seems to be on cusp of even more advances, with a particular light on the athlete with limb loss or other physical disabilities.

On target

In recent years, athletes with limb loss or other physical disabilities have taken on some of the world’s longest races, highest climbs and biggest waves. Shane Wurdeman, PhD, CP, who splits his time as a clinician for Hanger Clinic and a clinical biomechanist for Hanger’s Department of Clinical and Scientific Affairs, said sports can help veteran athletes stay competitive and introduce new athletes to a new level of activity.

“For individuals who were runners and lost that ability [due to amputation], or for those that have congenital [limb loss] and have never experienced running, to regain that [and] get back to life before amputation [can be] liberating.”

But athletes take part in more than running, Wurdeman added. “I have a [patient] right now who is playing football,” he said, “You [have] basketball, baseball, fencing and biking.”

Clay Claiborne, CPO, FAAOP
Clay Claiborne

“You also see athletes taking part in track and field, swimming and just getting back to the gym,” Ronnie Dickson, CP/LP, lower limb and athletic specialist at Prosthetic and Orthotic Associates, told O&P News.

“I think a part of that is influenced geographically by what kind of recreational opportunities are close to you. I know a lot of people who have been involved golf, [or who] get into some of those fringe sports like rock climbing or things that are accessible, but not as publicized as some of the others.”

Dickson, who is also the chair of the Adaptive Climbing Committee for USA Climbing and founding board member of the Adaptive Climbing Group, is a silver medalist of the 2014 International Federation of Sport Climbing World Paraclimbing Championships. He said athletes who get involved in sports can work their way up to major achievements — athletes like Hugh Herr, PhD, amputee rock climber who has scaled the Appalachian Mountains, or Jessica Long, Paralympic swimmer who has a combined 17 medals and has competed the Paralympics multiple times.

Clay Claiborne, CPO, FAAOP, of Claiborne Prosthetics and Orthotics in Charlotte, N.C., told O&P News of a local patient who has seen recent success in athletics.

“I have a patient, Paul Peterson, who lost his limb at the age of 15 [years]. I saw great potential for him as a runner,” he said. “With the help of the Challenged Athletes Foundation, we were able to obtain a running prosthesis. From there, his life changed dramatically.

Image: Clay Claiborne, Claiborne Prosthetics and Orthotics.

Image: Clay Claiborne, Claiborne Prosthetics and Orthotics.

“Over the next year, he went from traveling to and participating in near-by running events, to traveling the world and competing at a world-class level.” Peterson now is now one of the top 10 100-meter amputee runners in the world, Claiborne said.

Jason Wening, MS, CPO, FAAOP, of Scheck and Siress Prosthetics, Orthotics and Pedorthics, who is a world record-holding, six-time medal winning Paralymic swimmer, told O&P News of another success story.

Jason Wening, MS, CPO, FAAOP
Jason Wening

“There is one patient I started working with who moved from Seattle and needed a new prosthesis. He started running, [he] started working and he got into triathlon,” Wening said. “[Since then], he has taken off and has done well for the short amount of time he has been training.”

Wurdeman spoke of a patient who wore leg orthoses that limited his mobility. He now plays for his high school varsity basketball team. Dickson recalled a patient who lost his lower limb in a motor vehicle accident. He became an avid rock climber and hiker.

A patient of Richard Nguyen, CPO, clinical manager at UCSF Orthotic and Prosthetic Centers, was injured by a semi-truck. Following gait therapy and a novel pair of leg orthoses, he travels the United States as a CrossFit trainer.


Off the track

While there are many success stories, sources said there are barriers as well. Physical challenges affect athletes on a case-by-case basis, but Wening said there are some common themes. One of them is improper fit. When a device is not sized or fitted properly, it can become uncomfortable and restrict movement, as well as cause skin breakdown, bone pressure and limb pain.

“It depends on whether you are using an everyday device or a prosthesis specially designed for sport. That can be part of the picture,” Wening said. “One of the big challenges is the fit of the orthosis or the prosthesis during activity.”

He said there are repetitive force cycles in activities like running and biking. “Devices for people engaged in high-impact activities may need different design considerations than devices for high-repetition activities,” Wening said.

Richard Nguyen, CPO
Richard Nguyen

Other challenges include style and over-exertion, sources said. “A barrier athletes tend to face is how they perform activity,” according to Nguyen. “A lot of times, they are looking at able-bodied athletes, trying to mimic them. Or maybe it is how they used to do things. [Now], they are figuring out how to do it with a prosthesis or orthosis.”

Wurdeman said when over-exertion is added, it could exacerbate any issues. “In any kind of sport, you typically push the limits of endurance,” he said. “There is the more common endurance of just exertion — being winded — [and] then exertion with regard to the stresses on the limb and the device. O&P athletes are pushing more force to their limb, so there has to be the ability to withstand that for a longer period.”

Shane Wurdeman, PhD, CP
Shane Wurdeman

Claiborne said when he attended the National Paralympic Championships in North Carolina earlier this year, he witnessed over-exertion firsthand. “Because Paul was competing, I had access to the track and many of the athletes,” he said. “During the competition, there were several whose feet broke. Because of the extreme torque the athletes are asking their feet to perform, I see this to be an increasing problem.”

Over-exertion can also cause problems for the residual limb, he added. “For prosthetic athletes, the most common physical challenge is residual limb pain. Increasing your activity will result in more issues with blisters and the effects of heat on the limb. Boney prominences within the limb [are] now asked to toughen up even more due to an increase in repetitions and pressure,” he said.

David J. Prince, unilateral amputee, world-record holding sprinter and two-time Paralympian, told O&P News that some athletes experience pain in their sound limb. “It is all based on how the sound limb establishes balance, stability and control while at top speed. As a unilateral amputee, your prosthetic blade is engineered for returning energy in a specific direction,” he said.

“When you practice with your prosthetic blade set up in a certain alignment and you run and do some training like that, it basically forces your sound limb to balance and stabilize [your] speed, your lateral movements, your medial movements [and] every possible dynamic that you can think of while running.”

David J. Prince
David J. Prince

Prince said this causes the sound limb to work “double-, triple-, quadruple-time, trying to make sure that you are running in a straight line.” If alignment of the prosthesis is incorrect, he added, an athlete can injure calve muscles, abductors and hamstrings.

On the orthotic side, sources said issues can include foot and neuroma pain stemming from improper fit or overuse. “[Orthotic patients] are not dealing with an amputation, but they [could] have weaker ankles or lower limb issues,” Prince said. “They are often dealing with limited range of mobility and trying to figure out how to best use that limb with an added device.”


Changing the game

Each athlete interacts with his or her device in a unique way, Prince added, and said learning and fine-tuning athletic style is key in being successful.

“Over the years of being a Paralympic athlete, I have started to learn a little more about the dynamic, the symmetry that I have to be constantly aware of while running. It means training, being form-focused and paying attention to technique,” he said. “Once you figure out how to do something slightly differently, then it becomes a lot easier. It is just about figuring out what works for the athlete, whatever the disability.”

“Truly, anything is possible,” Dickson added. “It is just a matter of how far you want to go with it, how much you are willing to put in and the support you have around you. I would approach that question more from a mental aspect than anything,” he said.

Ronnie Dickson, CP/LP
Ronnie Dickson

“The bulk of [the challenge] is wrapping your head around what the sport entails and coming up with creative ways to be resilient, whether that is modifying a device, changing perspective on how the sport can be performed or some sort of combination between the two.”

There are also new technologies that could help athletes overcome hurdles. Researchers have developed prosthetic socket interfaces that allow greater comfort and reduced perspiration. Some of the more advanced devices come close to emulating complex human joints. Microprocessor technology has enabled prostheses to adjust stride pattern and respond to changes in terrain.

Osseointegration virtually connects the residual limb to the prosthesis, allowing kinesthesia and proprioception. Novel exoskeletons are helping wheelchair users become ambulatory. Researchers have developed lighter, shock-absorbing devices that require less energy expenditure.

“The growth in the technology for prostheses is just awesome,” Prince said. “[Researchers] are combining athletic-type prostheses, like your running blades, and putting heels on them. The blade is engineered to keep you on your toe, to absorb and return energy and be as lightweight as possible.

“But when you are trying to play basketball and have quick maneuvers and adjust your speed laterally, then you have to have the stability of a heel. The development is going in a good direction.”

Individuals who have undergone limb salvage can run, play basketball and compete in track with the help of designs that incorporate dynamic materials, Wening added. “They are so specialized. If you want to talk about orthotics, there is an AFO that was designed for running for people with ankle and leg issues, especially limb salvage and ankle fusions — things that [when brought up], one normally would hear, ‘You cannot run this way,’” he said.

“Manufacturers are doing a better job of creating tools that can be used for a range of activities, that work well for a range of sports and allow people to perform at a high level.”

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‘Neck and neck’

According to some, however, the devices have worked too well for athletes. Sanctioning bodies have argued that certain prostheses give athletes with limb loss an unfair advantage in height and speed over able-bodied peers.

Rules set forth by the International Paralympics Committee (IPC) now prohibit the use of any device that enhances athletic performance through “machines, engines or robot mechanisms.”

A mixed-methods study of lower limb prostheses in Paralympic sports has led to a proposed series of guidelines that could assist in the development of sports policies. Conducted by Bryce Dyer, PhD, CSci, MIScT, CTPD, MIED, FHEA, head of research and professional practice in the Department of Design and Engineering at Bournemouth University, the study investigated controversy around the 2008 performance of sprinter Oscar Pistorius, who wanted to compete in both the Olympics and Paralympics.


Investigators reviewed performance data from the men’s 100-meter sprint event performed at the Paralympic games from 1976 to 2012. They compared the mean averages of the fastest three runners in each successive Paralympic Games for assessment to the nearest able-bodied equivalent, the Olympic Games.

The comparison was used to provide reference for changes taking place during the time period studied, assuming prostheses are not intended to boost performance. Three data sets were compared: amputee sprinting (AS), or the change from Paralympic Games to Paralympic Games between 1976 and 2012; able-bodied modern period (MP), or the change from Olympic Games to Olympic Games between 1976 and 2012; and the able-bodied inception period (IP), or the change from Olympic Games to Olympic Games between 1896 and 1932.

Findings showed that while able-bodied sprinting has seen consistent improvements in performance during the time period studied, amputee sprinting has undergone significant change in a short period of time. Dyer noted a large spike in 1988, when amputee sprinting results corresponded with the first widespread use of energy storage-and-release prostheses.

Consensus from leading prosthetists, disability sport academics, disability sport athletes, disability sport governing body members and disability sport spectators stated the following: lower limb prostheses should be classified as equipment and formally legislated when used for competitive running; submitted for evaluation if these were not formally approved by the IPC before use in competition; should be restorative in nature; and should restore functionality and contribute to limb and stride length of the user “of no greater magnitude than exhibited by the same region of the athlete’s biological lower limb.” The consensus did not address participation of bilateral amputees, according to the study.

Dyer subsequently conducted a quantitative-based analysis of video footage to evaluate step frequency and symmetry of runners competing T44/43 100-meter final at the 2008 Paralympic Games, the 2011 IPC World Athletics Championships and the 2012 Paralympic Games.

He determined that a prosthetic limb should be tailored not just for a specific sport, but for the event in which the runner is competing, and that limb prescription needs to not only consider limb-to-limb symmetry, but also the way the prosthesis performs at all points in the race.

Beyond the finish line

Although amputee sprinting improved along with the use of novel prostheses, Wening said, “so did the revolution in access to training, coaching and changes in the interface technology that reduced skin breakdown.”

Jeremey Campbell, a transtibial amputee and three-time Paralympic gold medalist, carries the American flag as crowd cheers.
Jeremey Campbell, a transtibial amputee and three-time Paralympic gold medalist, carries the American flag as crowd cheers.

Image: Hanger Clinic.

He said that allowed athletes to train longer and harder. Resources will continue to develop and novel technology could begin to bridge the gap between limitation and potential.

Events like the 2016 Cybathlon — the first “robot-assisted Olympics,” which will include brain-controlled interface, powered wheelchair and exoskeleton races — could further display the power of the O&P athlete.

The U.S. Department of Defense and Department of Veterans Affairs are funding research into the development of new O&P technology, sources said. “There is the U.S. Paralympics, the Never Say Never Foundation, the Challenged Athletes Foundation [and] several organizations that support athletes and access to sports,” Wening said.

The O&P athletic arena is changing and the stage is set for a new type of Olympic sport that could surpass its traditional counterpart. While technology may have some room to grow, experts predict a tipping point.

But it is not just about technology, Nguyen said, “these individuals and their efforts are what define them as athletes, not the devices. The products and services we provide assist them in their activities, but it is not what enables them.”

Sources agreed. They said as engineering and science transition from abstract to concrete, and as athletes continue to grow, it could spell a new era not only for sports, but for the O&P community as a whole. “Once those doors get opened,” Wening said, referencing the Olympic motto, “we will only go faster, higher, stronger.” – by Shawn M. Carter

Disclosures: Claiborne, Dickson, Nguyen, Prince, Wening and Wurdeman report no relevant financial disclosures.

Editor’s Note: This story includes a small representative sample of individual companies and products. O&P News does not intend to promote individual companies or their products, nor to achieve an industry-wide consensus on the issue. Sources contacted in developing this story were randomly selected.

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