The US Army is testing a "third arm" device that will be attached to soldier’s protective vests to lessen the weight on their arms.
Weighing less than 4 pounds, the body-worn weapon mount currently undergoing testing at the Army Research Laboratory, allows redirecting all of a weapon's weight to the body, making it easier for the Soldier to carry a more lethal firearm, the Army press release stated.
"With this configuration right now, we can go up to 20 pounds and take all of that weight off of the arms," said Dan Baechle, a mechanical engineer for the lab's Weapons and Materials Research Directorate.
The passive mechanical appendage, which is made out of carbon fiber composite, can be used in the prone position and on both sides of the body.
To test the device, researchers are conducting a pilot with a few Soldiers using an M4 carbine on a firing range at Aberdeen Proving Ground in Maryland, the release stated. As part of the pilot, Baechle said, the Soldiers wear electromyography sensors on their arms and upper body to measure muscle activity to determine if there's a change in fatigue when shooting with the device.
Researchers also score the Soldiers' shots to see if there's an improvement in marksmanship.
"The research and development we're focused on now is refining this device," Baechle said, adding that they're also working on it with the lab's Human Research and Engineering Directorate.
While the M4 is the only weapon currently being tested with the device, Baechle said, they plan to investigate other types of weapons with different calibers, like an M249 squad automatic weapon or M240B machine gun.
The third arm could also allow Soldiers to use future weapons with more recoil.
"We could potentially look at very high recoil systems that aren't going to beat up on the Soldier like they normally would," he said.
Researchers also plan to examine the device's potential applications for various fighting techniques, like shoot-on-the-move, close-quarters combat, or even shooting around corners with augmented reality displays, he said.
Other possible applications for the device include helping a Soldier keep his weapon close by as he cuts through a barrier with a power saw during a breaching operation. A Soldier might also use it to carry a shield as he leads other Soldiers in clearing a room.