Twelve years ago, 32-year-old San Luis Obispo resident Nate Smids had part of his right leg amputated after a snowboarding accident.
Now, he will play a role in helping determine the best exercise program for other amputees so they can avoid additional surgeries or injuries.
The way he exercises will provide useful data for a team of Cal Poly researchers studying how much stress amputees such as Smids place on their knees, hip joints and cartilage tissue.
The university received a $513,000 Department of Defense grant that focuses on measuring the impacts of different forms of weight-bearing exercises to the bodies of below-knee amputees. The goal is to prevent the onset of osteoarthritis.
The study will compare the impacts of cycling, elliptical and walking exercise using motion analysis and computer modeling.
Knee biomechanics will be evaluated for two groups between the ages of 18 and 50: a control group of 10 nonamputee subjects and a group of 10 amputee subjects. Most of the amputee participants will be veterans.
By the end of the three-year study, the goal is to provide information and data that could help amputees determine a best course of action for their exercise habits, movements and exertion to prevent future surgery or injury.
“The main thing that we want to do is help,” said Stephen Klisch, a Cal Poly mechanical engineering professor and principal investigator. “There is very little information in this area about the impacts of riding a bike and none about elliptical machines. We want to help people to live better lives, both vet and nonvet amputees.”
The grant, awarded through the U.S. Army Medical Research Acquisition Activity program, will include a team of Cal Poly engineers and kinesiologists, as well as local doctors.
Additional researchers include Matt Robinson of Hanger Prosthetics & Orthotics in San Luis Obispo; Otto Schueckler of the Central Coast Orthopedic Medical Group; and David Tuttle of Radiology Associates in Templeton. French Hospital in San Luis Obispo will provide MRI services.
Prosthetic limbs can’t replicate the body’s natural biomechanics in a completely natural way, so the movements of amputees can load more weight on certain parts of the body.
“Amputees who have one amputated prosthetic leg and one unaffected, intact leg tend to have a higher risk of osteoarthritis in their intact leg,” Klisch said. “It’s comparable to having an injury and favoring one part of the body to compensate for that injury. ... But the goal is for prosthetics to act in a completely natural way.”
Smids said his legs can get tired by the end of the day, particularly from certain exercises such as yoga and downhill cycling. He even surfs with a special prosthetic limb that has a strong grip on the board. That low-impact activity mostly uses his upper body, he said.
At night, relaxing or watching television, he’ll take off his prosthetic limb to rest his leg, though he lives a fairly normal life otherwise, he said.
“About 2 1/2 years ago, I had some achiness just under my kneecap,” Smids said. “I think I had a tear, but the pain went away. I have been pain-free ever since. ... I hope to stay that way for a long time.”
Osteoarthritis occurs when the cartilage and underlying bone get worn down, which can lead to a knee replacement. Symptoms of the condition include pain, swelling and stiffness, according to the Centers for Disease Control and Prevention.
Seventeen Cal Poly students are participating in the project, including six mechanical engineering majors who are being funded to lead the research: Alejandro Gonzalez-Smith, Greg Orekhov, Nina Yadlowsky, Jordan Skaro, Michael Rumery and Greg Lane.
“In the future, I would like to work in prosthetics and help to improve biomechanics so that amputees move with a natural gait,” said Yadlowsky, who will analyze the measurements and watch for errors.
When she first signed on, Klisch said Yadlowsky told him, “This is like a dream project for me.”
The activities will be performed in the university’s Human Motion Biomechanics lab, where other projects include knee biomechanics with Schueckler’s ACL reconstructive surgery patients, and youth pitching biomechanics with kids from the San Luis Obispo and Five Cities baseball little league teams.
“We expect that this and related projects will lead to a recommendation on the types and intensities of exercises that amputees should use for lifelong fitness sustainment while reducing their chance of developing osteoarthritis down the road,” Klisch said.