The mechanics of head-supported load carriage by Nepalese porters

Abstract

In the Everest valley of Nepal, because of the rugged mountain terrain, roads are nothing more than dirt paths and all material must be conveyed on foot. The Nepalese porters routinely carry headsupported loads, which often exceed their body mass, over long distances up and down the steep mountain footpaths. In Africa, women transport their loads economically thanks to an energy-saving gait adaptation. We hypothesized that the Nepalese porters may have developed a corresponding mechanism. To investigate this proposition, we measured the mechanical work done during level walking in Nepalese porters while carrying different loads at several speeds. Our results show that the Nepalese porters do not use an equivalent mechanism as the African women to reduce work. In contrast, the Nepalese porters develop an equal amount of total mechanical work as Western control subjects while carrying loads of 0 to 120% of their body mass at all speeds measured (0.5-1.7 m s −1 ), making even more impressive their ability to carry loads without any apparent mechanically determined tricks. Nevertheless, our results show that the Nepalese porters have a higher efficiency, at least at slow speeds and high loads.

Analysis of gait during independent and paired walking in adults with an intellectual disability: A case report.

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“…Children in Nepal and girls in some African cultures begin practicing load carriage at young ages as part of work and play. As adults, Nepalese porters and African women carry tremendous loads (70–200% of their body weight) for great distances, over rough terrain, and up and down steep mountainsides (Bastien et al 2016, Minetti et al 2006). They can freeload up to 20% of their body weight without increased energy expenditure (Bastien et al 2005, Heglund et al 1995).…”