Late last month, the U.S. Army announced that a unique technology to improve soldier shooting accuracy and reduce fatigue has advanced to the next testing phase.

“Right now we have a prototype that’s essentially a research platform that we’re using to investigate different types of materials — how materials and structures can stabilize a weapon or a shield, reduce fatigue on the Soldiers’ arms, but also improve accuracy,” said mechanical engineer Dan Baechle.

Using a mechanical apparatus, the lightweight device helps redistribute some of the burden soldiers carry in their arms and shoulders to their abdomen. Engineers at the Army Research Lab have been developing a mechanical “third arm” that attaches to a user’s back hip.

The Army began developing the concept in late 2015 when ARL engineers brainstormed ideas on how to make a dismounted soldier more lethal. Engineers began building the first prototypes in 2016. The focus of the project centered on providing stability for dismounted soldiers. ARL engineers are examining different types of spring materials to further balance the weapon against gravity. Last year, the Army formally announced the development of the first prototype, which weighs less than four pounds thanks to the use of CFRP composites.

“We started out with just trying to think of a way to help improve the lethality for the dismounted soldier,” Baechle said. “Generally that means stabilizing the weapon or giving the soldier a more powerful weapon. Can we stabilize that weapon to improve accuracy? But also if we’re stabilizing the weapon and taking the load off of the soldiers’ arms, does that improve the soldier’s readiness? Does it also improve the soldier’s accuracy with the weapon?”

Last summer, six soldiers volunteered to take part in a pilot study, where researchers placed special sensors to measure muscle activity. In particular, when holding a weapon or shield for extended periods of time, the arm begins to shake, impacting shooter accuracy. The six-person research team tested soldiers firing weapons with and without the apparatus. The Army found that the “third arm” reduced the fatigue and reduced the muscle activation for some soldiers.

The second prototype this will be tested on a minimum of 15 soldiers this spring. For more information, visit