The effects of habitual footwear use: foot shape and function in native barefoot walkers†

^†Winner of the Nike Award for Athletic Footwear Research presented at the IXth Footwear Biomechanics Symposium in South Africa, 2009.

Abstract

The human foot was anatomically modern long before footwear was invented, and is adapted to barefoot walking on natural substrates. Understanding the biomechanics of habitually barefoot walkers can provide novel insights both for anthropologist and for applied scientists, yet the necessary data is virtually non-existent. To start assessing morphological and functional effects of the habitual use of footwear, we have studied a population of habitually barefoot walkers from India (n = 70), and compared them with a habitually shod Indian control group (n = 137) and a Western population (n = 48). We focused on foot metrics and on the analysis of plantar pressure data, which was performed using a novel, pixel based method (Pataky and Goulermas 2008, Journal of Biomechanics, 41, 2136). Habitually shod Indians wore less often, and less constricting shoes than Western people. Yet, we found significant differences with their habitually barefoot peers, both in foot shape and in pressure distribution. Barefoot walkers had wider feet and more equally distributed peak pressures, i.e. the entire load carrying surface was contributing more uniformly than in habitually shod subjects, where regions of very high or very low peak pressures were more apparent. Western subjects differed strongly from both Indian populations (and most from barefoot Indians), by having relatively short and, especially, slender feet, with more focal and higher peak pressures at the heel, metatarsals and hallux. The evolutionary history of humans shows that barefoot walking is the biologically natural situation. The use of footwear remains necessary, especially on unnatural substrates, in athletics, and in some pathologies, but current data suggests that footwear that fails to respect natural foot shape and function will ultimately alter the morphology and the biomechanical behaviour of the foot.

Keywords:

• barefoot
• plantar pressure
• foot morphology
• footwear
• biomechanics
• physical anthropology

Acknowledgments

This project was supported by the Fund for Scientific Research – Flanders (project G.0125.05), by the University of Antwerp (BOF grant #1094) and by the Flemish Government through structural support to the Centre for Research and Conservation. Josie Meaney-Ward did careful language editing and five reviewers provided useful comments on a previous version of the manuscript, which was submitted for the 2009 Nike Research Award. We thank the entire staff of the Jain Institute of Vascular Sciences in Bangalore (Dr Vivekanand, Dr Vinaya, Dr Suresh, and especially the staff of the Diabetic Foot Clinic and of the Orthotic Department), Dr Rajendrakumar and his staff in KGF, and the full staff in Mandya. The warm hospitality (and superb food) of all five Vivekanand family members during the stays of KD in Bangalore is enormously appreciated. Finally, we thank all subjects, with a special mention for the 90-year-old woman in KGF who travelled 160 km on the back of a scooter especially for the pressure recordings.

Notes

^†Winner of the Nike Award for Athletic Footwear Research presented at the IXth Footwear Biomechanics Symposium in South Africa, 2009.