NATICK, Mass. -- When it comes to gaining insight into the effects of bulk from clothing and equipment on Soldier performance, researchers at the Natick Soldier Research, Development and Engineering Center are LEAPing at the chance.

Originally developed by the Marines and then adapted to meet the needs of the Army, the Load Effects Assessment Program- Army, or LEAP-A, tool consists of a series of obstacles and mission-relevant activities to resemble challenges that warfighters face in combat situations. LEAP-A provides a reliable method to measure the impact of clothing and individual equipment, or CIE, on Soldier performance.

Blake Mitchell, an NSRDEC engineering psychologist and team leader for the Human Factors Team, explained that the LEAP-A course is designed to assess equipment configurations impact on human performance, with the assumption that each of those configurations is influenced by weight, bulk, stiffness or flexibility.

"We conducted an earlier test systematically varying the weight, while attempting to keep bulk and stiffness constant," said Mitchell. "This time we are systematically varying the bulk while attempting to keep the weight and stiffness constant. This will help us to better understand what the role of bulk is in performance outcomes when completing the LEAP-A."

Mitchell explained that the Soldiers complete a warmup and perform two load transfer tasks --one horizontal between two equal height towers and one vertical from a low to a high tower. They also perform a vertical jump task, a marksmanship task and run the obstacle course, which requires them to maneuver through stairs, a hatch, and a tunnel -- followed by sprinting and then climbing stairs or a ladder. All of this is followed by an agility run with hurdles.

Soldiers also carry out a casualty drag, 180-pound mannequin; climb through a large and a small window; perform a bounding rush, sprint, drop into prone position, aim weapon and stand up; navigate the balance beam; crawl low, supine and high; climb over a courtyard and inner yard wall; repeat the marksmanship task; repeat the load transfer tasks; and repeat the vertical jump task.

"They give us subjective ratings on thermal sensation and comfort and perceived exertion pre- and post-obstacle course," said Mitchell. "They also rated the impact of bulk on the ability to perform the tasks."

The project is led, executed and funded by NSRDEC, and it is a collaboration between the Human Factors and the Biomechanics Teams within the Human Sciences Branch, Warfighter Directorate.

By understanding how bulks affects the Warfighter's ability to move and maneuver through the LEAP-A obstacle course, scientists and engineers will be able to implement modifications to optimize the design and integration of clothing and equipment -- thus, improving Soldier-System interface and performance.

"The goal is to better understand what the results from LEAP-A product tests mean, in this case focusing on the bulk of the product," said Mitchell. "For example, if a Soldier completes a course in 5 percent more time in body armor X than they did when in a baseline [or] duty uniform configuration, how much of that change in performance is due to the bulk that the body armor added?"

Mitchell said that the information learned from the effort will eventually transition to Product Director Soldier Systems Integration and test agencies, including the Aberdeen Test Center and Maneuver Battle Lab. The findings will also benefit the international defense research community through The Technical Cooperation Program -- which includes the United States, Canada, United Kingdom, New Zealand and Australia.


The U.S. Army Natick Soldier Research, Development and Engineering Center is part of the U.S. Army Research, Development and Engineering Command, which has the mission to provide innovative research, development and engineering to produce capabilities for decisive overmatch to the Army against the complexities of the current and future operating environments in support of the Joint Warfighter and the Nation. RDECOM is a major subordinate command of the U.S. Army Materiel Command.