The effect of carried loads on the walking patterns of men and women

Abstract

In order to determine the effect of loads worn or carried on walking mechanics, 1 1 men and 1 1 women were filmed using high speed cinematography as they performed overground walking at 1-78 m/s under five load conditions. The loads included a baseline condition in which subjects carried no added load, and additional loads of approximately 9, 17,29 and 36 kg consisting of standard military items. The latter two loads were added in the form of a framed rucksack system. Values for several variables frequently used to described temporal and kinematic characteristics of waking were quantified from the film. These included stride length, stride rate, single leg support time, double-support time, swing time and the forward inclination of the trunk. The results of the study demonstrated that the males and females displayed significantly different gait patterns under all load conditions. Not unexpectedly, the females required a higher rate of stepping than the males because of their shorter stride lengths. The results also demonstrated that the walking . patterns of both the male and female subjects were'affected by the increases in carried load. In general, stride length and swing time decreased while stride rate and double-support time increased with increases in load. There was also an increased forward inclination of the trunk but only for the two heaviest loads which were carried in a rucksack. While the changes in gait characteristics were relatively small for the male subjects, the females were affected to a greater extent thereby demonstrating a greater sensitivity to load magnitude. It was concluded that careful consideration must be given to the absolute loads carried by males and females. Not only is it important for load requirements to be lower for females because of the physiological implications but also because of biomechanical implications and the associated mechanical stresses which must be endured during locomotion. While this study was directed primarily towards military applications, the results should also have implications for load carrying in a variety of situations and environments, including industrial and recreational appiications.

Mechanics and energetics of load carriage during human walking

“…As for negative work, its magnitude also increased, primarily at the hip, and mostly near the end of swing phase. This might aid the faster swing that occurred with increasing double support time and relatively constant stride time (Birrell and Haslam, 2009;Martin and Nelson, 1986). These various changes in joint work accounted for the largely parallel changes in summed joint work and COM work with load.…”

The Effects of 10% Front Load Carriage on the Likelihood of Slips and Falls

“…Limited research suggests that front load carriage plays a moderate role in slips and falls although load carriage has been clearly shown to influence biomechanics of gait such as step length 15) and trunk rotations 16) . The present study was performed to evaluate if carrying a load in front would impair temporal-spatial gait characteristics (HCV, WV, and SL) and would influence slip severity (RCOF and SD I and II), and, ultimately, predisposed to slipinduced falls.…”

“…Shorter SL while carrying the load may be induced by the mechanism caused for slower HCV 15) . Decreased SL was indicated to lessen the likelihood of slip-induced falls because it tended to reduce the horizontal shear force in proportion to the vertical force at the shoe-floor interface resulting in smaller RCOF during heel contact [3][4][5] .…”

Load carriage induced alterations of pulmonary function

“…While numerous studies have investigated the effect of carrying loads on energy expenditure (Goldman and Inapietro 1962, Leu and Mahanty 1985, Pimental and Pandolf 1979, walking patterns (Martin 1986) and perception of exertion (Goslin and Rorke 1986), o'.ly one previous study has examined alterations in pulmonary function (Legg and Mahanty 1925). Legg and Mahanty (1985) reported that with five different load carriage systems carrying a load equal to 35% of the subject's body weight reduced FVC, FEV 1 and MVV 1 5 .…”