COLD REGIONS TEST CENTER, Alaska-- American Soldiers deployed to the world's worst combat zones depend on body armor to keep them safe.
Countless veterans of action in Iraq and Afghanistan can testify to the lifesaving utility of their armor.
Likewise, Soldiers count on body armor to fit and function well and not leave them permanently injured from body strain once they have returned to civilian life.
U.S. Army Cold Regions Test Center (CRTC), located near Delta Junction, Alaska, recently tested a new modular body armor system that can be scaled up or back in four tiers, depending on the severity of the mission. The tiers consist of a range of soft and hard plates, and the highest tier includes a combat shirt with integrated soft armor and groin protection.
Aside from putting this improved body armor through its paces in a brutally cold Alaska December, the test resulted in improved methodologies for human factors testing, and it all stems from the intensely dynamic flexibility of Soldier movement in combat.
"Anything you are doing as a Soldier is made up of compound, multi-joint movements," said Isaac Howell, test officer.
Howell, who spent 10 years in uniform and deployed to Iraq as an infantry officer, has particular interest and insight into the importance of fit and function for Soldier systems like body armor, and was excited to approach the test in a novel manner.
"The standard anthropomorphic measurements historically utilized in human factors engineering testing are static, not dynamic," said Howell. "You sit in a chair and bend over and I measure that angle with an instrument. That's a static measurement -- even a layperson can see the limitations in that kind of measurement."
Howell feels using a functional movement screen, a system developed by clinicians, physical therapists, and physiologists for use in the competitive sports world, is a great complement to this type of testing. Utilizing seven different exercises to screen the components of fundamental human movement, the screening system predicts the possibility of biomechanical injury due to poor movement based on a score test subjects get from performing a battery of exercises.
"In a test, you have to work with somebody who has good movement to begin with," said Howell. "If a person doesn't have good range of motion in their joints before they put on the armor, it's not going to provide the best data."
Howell began the test by having prospective participants perform five complex exercises wearing only summer physical training t-shirt and shorts. Soldiers passing the baseline test then did the same exercises in the first tier of body armor, progressing up to the fourth.
"From that we were able to see if wearing the extra levels of body armor restrict movement," said Howell. "Obviously it does to some degree eventually, but we were able to see if they still had an acceptable range of motion or how severe the degradation of motion was."
Exercises like the overhead deep squat employed in the screening are difficult, but nothing compared to what was in store once Soldiers from Fort Wainwright's 25th Infantry Division took the test outside into sub-zero winter. On foot march days, the Soldiers hiked eight miles in the given tier carrying a standard 35 to 40 pound pack, while wearing the weather-appropriate level of the Extended Cold Weather Clothing System. This three-hour ordeal was repeated wearing each configuration of body armor: if they were lucky, the Soldiers got breaks every 20 to 30 minutes.
"It depended on how cold it was: if it was really cold, we tried to just keep moving," said Howell, who marched alongside. "You try not to sweat while you're walking, but you really can't avoid it when you're carrying that much gear. Sweating is very dangerous in an extreme cold environment."
On the obstacle course, the Soldiers had to wear each configuration of the armor through an ordeal that included a 400 meter run, a low-crawl tunnel, mock windows, stairs, and ladders of varying widths and heights. Finally, they each did a 200 meter shuttle run while lugging two 30 pound ammunition cans.
"That day was a real smoker," said Howell.
To test the new quick-release feature of the armor, the Soldiers had to release, reassemble, and don their armor within seconds, repeating the task scores of times for each configuration in standing, kneeling, and prone positions as sub-zero snow blew past and data collectors looked on. To ensure a Soldier wearing the armor could effectively remove a wounded comrade also wearing it from danger, the testers performed casualty drag evaluations with real Soldiers portraying the mock wounded.
The Soldiers also did marksmanship training wearing the armor, firing over 2,400 rounds in the process.
One final portion of the test, ingress and egress from a combat vehicle, had special applicability to the latest variant of the Stryker combat vehicle, which was simultaneously under evaluation at CRTC. The Soldiers entered and exited all hatches of the vehicle wearing the full complement of armor and all seven levels of the ECWCS system , ensuring everything in the vehicle could be touched and reached, and wouldn't snag their gear. The findings applied to both tests, which both test officers saw as a bonus.
"It was great coordination between the two tests to pick the appropriate miserable day to get the Soldiers to do some limited ingress-egress testing," said Richard Reiser, test officer. "When this vehicle is fielded and the Soldiers have the new body armor, we'll already know it isn't an issue for ingress and egress."
"The whole test was taxing for the Soldiers, but they put in an outstanding effort," said Howell. "We found a lot of limitations and improvements the project manager is already improving upon or implementing."
Social Sharing