Studies target reducing low back injury and improving prosthetics for military

Tampa, FL (Sept. 22, 2011) — The University of South Florida School of Physical Therapy & Rehabilitation Sciences has received a $1.59-million U.S. Department of Defense award for leading-edge musculoskeletal research intended to benefit active duty soldiers and veterans and improve military preparedness.

The award will fund two major studies – one investigating whether a specific exercise training regimen may protect against low back injury in combat soldiers and the second evaluating the best prosthetic foot to accommodate soldiers and veterans with below-the-knee amputations who wish to return to active duty. Both two-year studies, about $715,000 each, are randomized controlled trials – considered the most reliable and impartial method of determining which rehabilitative treatments and adaptive devices work best. The research will test in military populations an exercise therapy and technologies that have already shown promise in civilians.

L to R:  The USF physical therapy team leading the DOD-sponsored projects — Drs. Jason Highsmith (prosthetics), William S. Quillen (prinicipal investigator), and  John Mayer (low back injury).

“This latest federal award clearly places the University and our School as a key Department of Defense partner for evidence-based research involving prosthetics and low back injury risk reduction,” said the project’s principal investigator William S. Quillen, PT, DPT, PhD, FACSM, associate dean for the USF College of Medicine and director of its School of Physical Therapy & Rehabilitation Sciences.

“Finding the best interventions for our warfighters and wounded warriors in both these areas is of great interest to the military,” said Quillen, a former U.S. Navy physical therapist.

The Department of Defense research award was sponsored by U.S. Rep. Gus Bilirakis and supported by Rep. C.W. “Bill” Young. Both studies are scheduled to begin later this fall.

Low back injury study: Reducing the lingering pain of war

The USF low back injury study will test in healthy soldiers the effectiveness of a high-intensity exercise training program that isolates and strengthens the lumbar extensor muscles – those long, large muscles used to keep the arch in the back. Studies have shown that targeting this muscle group with specialized exercise protocols helped reduced the risk of low back injury in civilian workers, but the approach has not been transferred widely to military settings.

The low back injury study will be led by John Mayer, DC, PhD, associate professor and Lincoln Endowed Chair in Biomechanical & Chiropractic Research at the USF School of Physical Therapy & Rehabilitation Sciences. The USF team will work with co-investigator John Childs, PT, PhD, MBA, associate professor and director of research in the U.S. Army-Baylor University Doctoral Program in Physical Therapy. Dr. Childs and the Army Medical Department (AMEDD) Center and School are partnering with the The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. to conduct the study, which USF designed and will oversee. The trial will enroll soldiers in the 32nd Combat Medic Brigade at AMEDD Center and School, a comprehensive military medical training facility in Fort Sam Houston, TX.

John Mayer  is leading  a project investigating whether a specific exercise training regimen may protect against low back injury in combat soldiers.

“The lumbar extensors are a weak link for back pain. People with poor strength and endurance of this muscle group are more prone to back injury.” Dr. Mayer said. “Our ultimate goal is to determine whether an advanced exercise protocol targeting lumbar extensor muscles will be preventive – in essence, inoculating soldiers against low back injury and pain in the extremely physically demanding field of combat.”

Low back pain is one of the most frequent causes of medical visits and lost training and duty time in the U.S. Armed Forces, according to a report by the Armed Forces Health Surveillance Center. A recent study from Germany indicated that only 13 percent of soldiers evacuated out of combat operations in Iraq and Afghanistan for back pain ever return to active duty. Often, injuries leading to disabling back pain were not sustained directly during battle, but in the interim – after a fall, while lifting heavy loads, driving or marching over rough terrain, during fitness training.

“All kinds of things put pressure on the back and lead to high incidences of back injury in the field, from the weight of full body armor to bouncing around in convoys,” said Childs, an Air Force lieutenant colonel. “There’s a tendency to ignore or downplay back pain because soldiers don’t want to appear weak. It can have a demoralizing effect.”

Lt. Colonel John Childs, co-investigator for the low back injury study.

The researchers will follow approximately 600 soldiers training to become combat medics at the Fort Sam Houston army base over 12 weeks. All will complete the Army’s standard fitness program for new recruits. In addition, the 300 soldiers enrolled in the investigational group will undergo high-intensity, progressive resistance training on a computerized machine (MedX lumbar extension dynamometer, WellTek Inc, Orlando, FL) designed to isolate and build the strength and endurance of the lumbar extensor muscles. The other 300 soldiers (control group) will perform low-intensity floor exercises to stabilize their abdominal core muscles.

Both the investigational and control exercise interventions will be performed once a week over the 12-week study. The strength and endurance of the soldiers’ lumbar extensor muscles will be measured before the study begins and after it ends.

The researchers hypothesize that the investigational group’s targeted intervention will increase lumbar muscle function significantly better than the control group’s core muscle exercise intervention. Dr. Childs is also performing other studies at the Army Medical Department Center & School to determine optimal exercise and educational approaches to prevent and manage low back pain in soldiers.

Foot prosthetics study: Returning amputee soldiers to active duty

The USF prosthetic research has the potential to transform the lives of the growing number of young amputee soldiers by giving them the option of returning to active service — possibly even the war zone — if they desire and can perform the functions required of the job.

The study testing the effectiveness of high-tech, multifunctional prosthetic feet will be led by Jason Highsmith, DPT, 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 rigorous and agile maneuvers soldiers must perform on the battlefield – from running and jumping to dodging, crawling and climbing.

The trial will involve soldiers who wear prostheses for below-the-knee amputations – the most common kind of lower limb loss.

Jason Highsmith is leading the second project evaluating the best prosthetic foot to accommodate soldiers and veterans with below-the-knee amputations.

“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 dramatically – up from 88 in 2009 to 182 last year, according to the Armed Forces Health Surveillance Center. Along with higher survival rates, better prosthetics 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 the three commercially-available, latest generation prostheses – all integrating varying degrees of rotational, shock absorbing and energy returning characteristics.
The double-blind randomized trial will enroll 28 physically fit people. Half will be high-functioning amputee soldiers and veterans recruited from the Wounded Warriors Project, Walter Reed Army Medical Center 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 prosthetics – 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.

– USF Health –

USF Health is dedicated to creating a model of health care based on understanding the full spectrum of health. It includes the University of South Florida’s colleges of Medicine, Nursing, Public Health and Pharmacy, the School of Biomedical Sciences and the School of Physical Therapy and Rehabilitation Sciences; and the USF Physician’s Group. Ranked 34th in federal research expenditures for public universities by the National Science Foundation, the University of South Florida is a high impact global research university.

– Photos by Eric Younghans, USF Health Communications

Media contacts, USF Health Communications:
Anne DeLotto Baier, (813) 974-3300, or abaier@health.usf.edu
Susanna Martinez Tarokh, (813) 974-2776 or smartin1@health.usf.edu