The University of South Florida (USF) School of Physical Therapy & Rehabilitation Sciences has received a $715,000 award from the U.S. Department of Defense (DOD) to fund a two-year, randomized-trial study evaluating the best prosthetic foot to accommodate soldiers and veterans with transtibial amputations who wish to return to active duty. The research will test in military populations technologies that have already shown promise in civilians.
The DOD research award was sponsored by U.S. Rep. Gus Bilirakis (R-FL) and supported by Rep. C.W. “Bill” Young (R-FL). The study is scheduled to begin later this fall.
Jason Highsmith is leading a study to evaluate the best prosthetic foot to accommodate soldiers and veterans with transtibial amputations. Photograph by Eric Younghans, courtesy of USF Health Communications.
The study testing the effectiveness of high-tech, multifunctional prosthetic feet will be led by M. Jason Highsmith, DPT, CP, FAAOP, USF assistant professor of physical therapy, who specializes in research to improve prosthetic options for those who lose limbs from traumatic injury and diseases. Highsmith and colleagues at the USF School of Physical Therapy & Rehabilitation Sciences will evaluate how well three different types of prosthetic feet work for the maneuvers soldiers must perform on the battlefield-from running and jumping to dodging, crawling, and climbing.
“A tactical unit can only move as fast as its slowest member,” Highsmith said. “This will be one of the first studies to compare the physical performance of highly mobile amputee soldiers using optimal components with that of non-amputees….We hope to identify which prosthetic foot may be best suited for military applications.”
Scientifically determining which prosthesis comes closest to a real foot when performing battlefield maneuvers is important, Highsmith said, because a person with an amputation uses more energy than someone with a natural foot for comparable movements at the same speed.
The number of soldiers in Iraq and Afghanistan with deployment-related amputations continues to rise-up from 88 in 2009 to 182 in 2010, according to the Armed Forces Health Surveillance Center. Along with higher survival rates, better prostheses and treatments have improved amputees’ ability to regain mobility. More of these amputee soldiers than ever before are seeking to return to the front lines.
The USF researchers will test three commercially-available, latest generation prostheses, all integrating varying degrees of rotational, shock-absorbing, and energy-returning characteristics-the Re-Flex Rotate™ (formerly Ceterus) and the Vari-Flex®, both by Össur, Reykjavik, Iceland; and the Silhouette, Freedom Innovations, Irvine, California.
The double-blind randomized trial will enroll 28 physically fit people. Half will be high-functioning transtibial amputee soldiers and veterans recruited from the Wounded Warriors Project, Walter Reed National Military Medical Center (WRNMMC), and veterans’ hospitals. The other half (control group) will be non-amputees, including accomplished civilian athletes and law enforcement officers.
Participants will be evaluated wearing each of the three different prostheses-both in USF’s Human Functional Performance Laboratory, where they will walk and run on treadmills, and at Hillsborough County Sheriff’s Office training facilities, where they will perform tactical maneuvers like charging up inclines, climbing ropes and slalom running that requires a combination of speed, agility, and balance. Non-amputees will undergo the same tasks in both settings. In the lab, the researchers will monitor such measures as range of joint motion, prosthetic foot power, oxygen consumed, and energy expended. In the field, they will evaluate gait efficiency, prosthetic preference, and task difficulty as rated by study participants.
“We’re upping the ante on the scientific rigor applied to prosthetic research,” Highsmith said. “Anything we can do to advance knowledge, reduce disability, and improve the lives of our wounded soldiers who have served our country so selflessly and constantly seek to stretch their limits is valuable.”
Advanced prosthetic research involving military amputees may ultimately benefit civilian amputees with physically challenging occupations or recreational pursuits such as firefighters, police officers, marathon runners, and rock climbers, he added.
