BEST FOOT FORWARD
ECU research evaluates prosthetic paws
April 18, 2012
ECU News Services
An East Carolina University graduate student is working to enhance the quality of life for Zeus, a 6-year-old Siberian Husky who wears a prosthetic paw.
Zeus had part of his left foot amputated after he was attacked as a puppy. Last year veterinary medicine orthopedic surgeon Dr. Marcellin-Little at North Carolina State University operated on Zeus, attaching an artificial limb to the dog’s bone.
In a collaboration with ECU student Robert Brady, Marcellin-Little is now conducting research to determine which of three choices will provide the best possible prosthetic paw for Zeus and other animals who may need an implant in the future. The researchers hope to publish their results in the Veterinary and Comparative Orthopaedics and Traumatology journal.
Working in ECU’s Biomechanics Lab in the College of Health and Human Performance, Brady is conducting gait analysis on the three different “paws” – a polyurethane-filled tennis ball developed as a prosthetic at NCSU, a spear-shaped polyurethane prosthetic foot made by Bio-Tech in Durham and a light and durable carbon fiber foot made at NCSU.
The study will test how the three prosthetic attachments that vary in shape, weight and height affect the gait, or walking patterns, of the dog. The best choice will give the dog the most natural gait.
Brady gathered data for the study by outfitting Zeus with infrared markers on boney areas like the elbow, shoulder and carpus (wrist) on both front limbs. He used 3-D motion capture software and infrared cameras to determine where Zeus’s joint centers were. With that information, he could calculate variables such as joint angle and rotational speed, as well as the length of each step.
A forceplate which Zeus walked across provided data on the amount of force each paw exerted on the ground.
“Ideally each paw would support the same amount of weight and we can see if one prosthetic allows Zeus to be more balanced than the others,” Brady said. “This may indicate a better design than the others.”
The equipment in the lab allows researchers to determine differences in both walking patterns and the force applied by each limb, Brady said. “We can compare these to normal healthy dogs to see which prosthetic best mimics natural gait.”
Analyzing the results will take some time, so researchers have not yet determined the best choice. Researchers hope to find a prosthetic that will give Zeus the most normal function. That would “allow Zeus to get around better and live with a higher quality of life,” Brady said.
“This means a less restriction motion and hopefully less stress on the rest of his body that must compensate for his limb loss.”
Project results will help Zeus and other domestic animals requiring a prosthesis. Helping animals is a cause dear to Brady’s heart. He plans to earn a doctor of veterinary medicine degree and continue applying his biomechanics background to benefit animals needing a prosthetic limb after trauma or due to genetic malformations.
ECU kinesiology professor Dr. Paul DeVita paved the way for Brady conduct his study in ECU’s biomechanics lab, normally reserved for humans. The research will benefit animals and provide a good foundation for Brady’s future studies in veterinary medicine, DeVita said.
Brady earned an undergraduate degree from ECU as a health fitness specialist and is now pursuing a master of science in kinesiology with a concentration in biomechanics. He is a graduate teaching assistant in the Department of Exercise and Sport Science. A native of Tarboro, Brady plans to graduate in May 2012.
Additional information about Zeus and the procedure is available at http://www.cvm.ncsu.edu/news/2011-04-03-Pioneering-Implant-Surgery-Aids-Zeus-and-Prosthetic-Limb-Design.html.