THE TACTICAL MARCH: QUANTIFICATION OF THE GAIT AND ECONOMY OF THE AIRBORNE SHUFFLE IN TORSO LOADED U.S. SOLDIERS

Abstract

During torso loaded tactical marching U.S. soldiers sometimes utilize the airborne shuffle, which is a purposeful manipulation of the walking gait characterized by a shortened stride length. This dissertation was designed to describe the gait characteristics and compare physiological between walking and the shuffle while torso loaded in U.S. Army soldiers (N = 11). In the first study, the gait characteristics during torso-loaded and unloaded walking and shuffling at 3.0 mph were compared. Differences in speed and economy of the preferred walking speed (PWS) and the preferred shuffle speed (PSS) were evaluated in the second study. The oxygen cost (VO2) at the PSS and the most economical shuffle speed (ESS) were assessed in the final study.

Stride length (p < .001), stance time (p < .001), swing time (p < .001), single support time (p < .001), and double support time (p < .001) were shorter while stride frequency (p < .001) was greater during the shuffle than while walking at 3.0 mph. Swing time (p = .02) was shorter and double support time (p < .05) was longer when loaded. The preferred speed (p = .04), VO2 (p = .002), heart rate (HR; p = .002), respiratory exchange ratio (RER; p = .001), Ve (p = .002), and rating of perceived exertion (RPE; p = .002) were higher at the PSS than at the PWS. The VO2 was lower at the ESS than at the PSS (p = .005), but speed (p = .27), HR (p = .17), RER (p = .87), ventilation (p = .46), and RPE (p = .36) were not different.

Overall, the gait characteristics of the shuffle were significantly different from those of a walking gait. The shuffle was less economical at preferred speeds than a walking gait, and the economy at the PSS and at the ESS were different. While there may be benefits to using the shuffle for decreasing stress on the lower limbs, a walking gait should be prioritized over the shuffle during torso loaded tactical marching as the shuffle is less economical and is perceived as more difficult compared to walking.