Many health professionals portent sandals (i.e thongs or flipflops) cause abnormal foor mechanics suffice they may present a potential health hazard to growing feet. These fears are to date not supported or refuted by independent quantitative data . A recently published, small study to compare the effect of thong footwear on children's barefoot has been published. Researchers used three dimensional foot analysis of walking and jogging on thirteen healthy children (age 10.3 +/- 1.6 SD years) randomly selcted. Kinematic data weas was collected using a 14 camera motion analysis system (Cortex, Motion Analysis Corporation) and simultaneous ground reaction force was measured with a Kistler force platform. A three-segment foot model was used to describe three dimensional ankle, midfoot and one dimensional hallux kinematics during the stance sub-phases of contact, midstance and propulsion. Researchers found wearing thongs increased ankle dorsiflexion during contact; increased midfoot plantarflexion during midstance ; and increased midfoot inversion during contact at heel strike . Researchers concluded these adjustments were the likely result od adjusting the foot to accommodate the sandal, but the overall findings were suggestive foot motion in thongs was replicable of barefoot motion and therefore unlikely to cause undue harm. This is of course a small study but the findings are at odds with those who believe thongs are bad for children’s feet.
Chard A, Greene A, Hunt A, Vanwanseele B and Smith R 2013 Effect of thong style flip-flops on children's barefoot walking and jogging kinematics Journal of Foot and Ankle Research 2013, 6:8 doi:10.1186/1757-1146-6-8