Yet another pattern of foot strike use is reported for the Tarahumara, a minimally shod population of traditional farmers living in the Sierra Madre Occidental of Northwestern Mexico.13 The Tarahumara are renowned endurance runners, running 75 km or more

in traditional ball games and, in recent years, competing in ultramarathons.14 Tarahumara traditionally wore simple rawhide sandals (huaraches), and many continue to do so today, although some have adopted conventional running shoes. 13 Lieberman 13 reported that 89% of Tarahumara who wear conventional shoes habitually RFS, while Tarahumara who wear traditional huaraches tend to MFS or FFS. In this study we examined foot strike patterns and running kinematics among traditional Hadza hunter-gatherers in Northern Tanzania. Imatinib purchase As described in detail elsewhere,15 traditional Hadza subsist almost entirely on wild check details foods, hunting and gathering each day on foot and with simple hand tools. Traditional Hadza have no agriculture, livestock, or machinery. Women typically walk 6 km each day gathering wild berries, tubers, and other plant foods, while men walk an average of 11 km per day, hunting small and large game with bow and arrow, and gathering honey.15 and 16 The landscape they inhabit is semiarid savannah with a patchy

mix of forest and grassland cover; the ground is often rocky, and low craggy hills are common. While the Hadza are highly active, they rarely run.15 Musiba and colleagues17 conducted a study of walking gait and foot dimensions among substrate level phosphorylation traditional Hadza. As discussed in that report, Hadza adults typically wear simple sandals made from repurposed tire rubber, common throughout East Africa. These sandals have relatively thin (∼1 cm) soles that offer protection from sharp rocks

and thorny plants but do not provide any cushioning or elevate the heel. Traditional Hadza can therefore be categorized accurately as “minimally shod”, and their feet display many of the same features (e.g., splayed toes, greater foot width) evident in habitually unshod populations.17 and 18 While Musiba and colleagues17 did not examine running, self-selected speeds during walking trials reported for Hadza adults (1.15 m/s) were relatively fast compared to other traditional, unshod populations, and the Hadza also used greater stride frequencies and stride lengths. We used high-speed digital video to analyze foot strike patterns and limb-segment angles of Hadza adults and juveniles running at a range of speeds. Our objectives were to determine the frequency of RFS, MFS, and FFS among the Hadza, to investigate the effects of speed and age on foot strike patterns, and to compare these data to published values for the Kalenjin and Daasanach. We predicted that the Hadza, who lack the training and experience in endurance running common among the Kalenjin, would exhibit foot strike patterns more similar to the Daasanach.