Influence of arm swing on cost of transport during walking.

Myriam L De Graaf,Han Houdijk,Sjoerd M Bruijn,Juul Hubert

doi:10.1242/bio.039263

Abstract

ABSTRACTNormal arm swing plays a role in decreasing the cost of transport during walking. However, whether excessive arm swing can reduce the cost of transport even further is unknown. Therefore, we tested the effects of normal and exaggerated arm swing on the cost of transport in the current study. Healthy participants (n=12) walked on a treadmill (1.25 m/s) in seven trials with different arm swing amplitudes (in-phase, passive restricted, active restricted, normal, three gradations of extra arm swing), while metabolic energy cost and the vertical angular momentum (VAM) and ground reaction moment (GRM) were measured. In general, VAM and GRM decreased as arm swing amplitude was increased, except for in the largest arm swing amplitude condition. The decreases in VAM and GRM were accompanied by a decrease in cost of transport from in-phase walking (negative amplitude) up to a slightly increased arm swing (non-significant difference compared to normal arm swing). The most excessive arm swings led to an increase in the cost of transport, most likely due to the cost of swinging the arms. In conclusion, increasing arm swing amplitude leads to a reduction in VAM and GRM, but it does not lead to a reduction in cost of transport for the most excessive arm swing amplitudes. Normal or slightly increased arm swing amplitude appear to be optimal in terms of cost of transport in young and healthy individuals.This article has an associated First Person interview with the first author of the paper.

Highlights

Human locomotion distinguishes itself from that of many other vertebrates due to its predominantly two-legged nature
This study explored the relation between arm swing amplitude, vertical angular momentum, ground reaction moment and cost of transport by having participants walk with different styles and amplitudes of arm swing
Our findings support the hypotheses that vertical angular momentum (VAM) and ground reaction moment (GRM) decrease with increasing arm swing amplitude

Summary

Introduction

Human locomotion distinguishes itself from that of many other vertebrates due to its predominantly two-legged nature. It is not surprising that most research into human locomotion focuses on the lower extremities, while the contribution of the upper extremities is neglected. The arms do appear to play a significant role in locomotion. Studies have shown that people consume more energy when they do not swing their arms during walking (Collins et al, 2009a; Umberger, 2008). This indicates a cost-reducing function of arm swing. There is evidence that arm swing may be involved in regulating the stability of locomotion (Meyns et al, 2013)

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