Dynamic foot function and morphology in elite rugby league athletes of different ethnicity

It has long been assumed that foot function and morphology differ between ethnicities. However, quantitative research proving or disproving this relationship is sparse. As a starting point, the objective of this study was to investigate the plantar loading characteristics and foot geometry of athletes from three ethnicities, being Caucasian, Maori and Pacific Islanders. Four plantar pressure parameters were compared in 28 male elite rugby league players using an EMED-AT plantar pressure distribution platform [Novel GmbH, Munich, Germany] and the five-step method. Foot geometry measures were also taken, including arch index, coefficient of spreading, hallux angle and sub-arch angle. Five trials were collected per foot at a self-selected speed. It was found that Caucasian and Maori subjects had a relatively wider forefoot than the Pacific Island subjects; however the Pacific Islanders' foot was found to be wider than both these ethnicities in absolute terms. While Caucasian subjects loaded the toes to a much greater extent than the Maori and Pacific Island subjects, the latter demonstrated a greater loading of the mid and forefoot regions. Pacific Island subjects revealed a significantly more pronounced hallux valgus angle as compared to the Caucasian and Maori subjects. The results of this study may be relevant for/should be taken into consideration in footwear design issues, where allowances need to be made during the design process for anatomical differences between ethnicities. However these observations cannot be generalised to whole ethnic populations, and further research is required on non-athletes to build on the current research findings.