Influence of Various Thong Style Flip-flops on Gait Kinematics and Lower Leg Electromyography

Abstract

Flip-flops are a common footwear choice for the masses. This influx of flip-flop usage is in despite of the plethora of anecdotal evidence and consensus among the health field that flip-flops are not conducive to the health of individuals’ lower extremities. The influence of footwear research on gait measures can be seen in the ever changing design of running shoes and there is abundant research of the effects of orthotics on gait, but still a lack of research on the effects of flip-flops on gait exists. The purposes of this investigation were; (1) to examine the effects that different components of the thong style flip-flop have on gait kinematics in individuals classified with normal arched (NA) feet; (2) to investigate the effects that a thong style flip-flop arch support has on gait kinematics of individuals classified with either low (LA), normal (NA), or high arched (HA) feet; and (3) to determine if there is an increase in muscular activity of the tibialis anterior (TA) at the ankle during the swing phase of gait when wearing thong style flip-flops in individuals classified with NA. The results show that flip-flops decrease stride length and peak eversion when compared to barefoot. In addition, a flip-flop with components such as an arch support, midtarsal support, toe ridge, and wider straps result in a gait which resembles a “normal” gait in college aged females with NA. The results also show that for LA, NA and HA individuals, a flip-flop with arch support resulted in a gait that resembled a “normal” gait compared to a flip-flop without an arch support. Finally, the current study found that increased activity of the TA was observed without a subsequent increase in dorsiflexion of the ankle in two out of three flip-flop conditions. In conclusion, no flip-flop investigated was exactly like walking barefoot; however, certain structural components of flip-flops do result in a gait similar to walking barefoot. Future research is still needed to investigate and design a flip-flop that results in a gait identical to walking barefoot.