ABERDEEN PROVING GROUNDS, Md. (Feb. 21, 2014) -- A U.S. Army Public Health Command, or USAPHC, team is conducting a project that suggests that the Army's new parachute system is more effective at reducing injuries in Soldiers than the previous system.
Over the past three years, the Injury Prevention Program has been analyzing data from parachute jumps conducted by the 82nd Airborne Division, 18th Airborne Corps and 18th Air Support Operations Group, all based at Fort Bragg, N.C.
"On a number of occasions, we traveled to Fort Bragg to evaluate jumps and to look at procedures," said Joseph Knapik, a research physiologist who served as the lead scientist for the project.
The results of the study were surprising.
"Overall injury risk was reduced by half with the T-11 parachute compared to the T-10," said Knapik.
In 2010, the Army starting using the T-11 Advance Tactical Parachute System for its parachuting Soldiers.
The Army had been using the older, T-10 parachute since 1952.
"This original system was designed to carry a Soldier and his equipment, but that parachute was designed for a maximum load of 350 pounds," said Knapik.
Since the introduction of the T-10, however, the average size of America's Soldiers and the amount of equipment they are required to carry into battle have both increased--and in parachute operations in Iraq and Afghanistan, average loads were 327 to 380 pounds.
In order to address the shortcomings in the T-10 parachute system, the Army developed the T-11 system, which is designed to hold 400 pounds.
The Army, however, still wanted a formal study that compared injury rates between the two parachute systems.
"Parachuting injuries are the sixth leading cause of hospitalization in active-duty Soldiers," said Bruce Jones, physician and Injury Prevention Program manager at the USAPHC. "Eighty percent of these injuries result in a need for medical evacuation, so we are greatly concerned with ways to reduce these injuries in our Army population."
On average, there was a risk of nine injuries per 1,000 jumps when U.S. Army paratroopers conduct a jump with the older, T-10 parachutes but only 4.5 injuries per 1,000 jumps when using the T-11 parachutes. Injuries involved virtually all parts of the body, but the head and ankle regions were the locations with the largest number of injuries, regardless of the type of parachute.
Data were collected under all types of operational conditions including day and night jumps, with and without combat loads, and in a variety of weather conditions including various wind speeds, temperatures and humidity. Even after statistically controlling for these factors, injury risk was still substantially lower with the T-11 parachute.
Knapik has many hypotheses on why the T-11 parachutes resulted in lower injury risks to Soldiers.
"Because of its shape (modified cruciform), the T-11 parachute becomes vertically stable very soon after deployment and does not oscillate like the T-10," said Knapik. "Oscillations can increase injury risk by increasing the impact energy on ground contact."
Additionally, the new parachutes offer other safeguards.
"The T-11 parachute incorporates changes in the descent rate, which reduce ground impact energy," said Knapik.
The Army is increasing its production of the T-11 parachutes, with 14,000 systems already in place at Fort Bragg, and phasing out the T-10 parachutes, according to Army researchers. Although more study is necessary, USAPHC scientists said they are pleased to work on a project that identifies how to reduce injuries in the Army population.
"It's rewarding to see that we are providing the science behind the Army's transition to the new parachutes," said Ryan Steelman, Injury Prevention Program epidemiologist, who was also a key contributor to the study. "The most enjoyable aspect of doing my job is helping Soldiers stay injury-free and combat-ready."