Abstract
Based on previous studies, foot muscle strength may be associated with balance, and has seen improvements with four-week foot muscle strengthening interventions. Runners have improved foot muscle strength with four-week minimalistic footwear interventions. However, little research has investigated the effectiveness of minimalistic footwear use among a general, non-athletic population and its effect on foot muscle strength. Minimalistic footwear use for daily activities may provide as an alternative to improve foot muscle strength versus foot muscle strengthening interventions. Therefore, the aim of this randomized pre/post study design was to explore the impact of minimalistic footwear (MFW) vs. conventional footwear (control) use on foot strength and balance in a healthy, non-athletic population after a four-week interventional period. Participants (n = 6) were asked to continue their daily routine in either their own conventional footwear (n = 3) or in minimalistic footwear (n = 3) for five days per week over four weeks. Step counts were tracked using Google Fit during the intervention. Foot muscle strength was evaluated via maximum isometric contractions of the plantar foot muscles, dynamic balance via the Y-Balance test, and static balance via changes in center of pressures (COP) speeds with eyes open and closed. Linear mixed models were performed to analyze the effects of group, time, and group and time (p < 0.05). Y-Balance test results were significant in the MFW group compared to the control when analyzing the interaction effect of group and time (t(6.00) = 3.36, p = 0.015); 7.51 % group difference). COP speeds (interaction effect of group and time: (t(6.00) = - 0.160, p = 0.878); (t(6.00) = - 0.401, p = 0.702) and foot strength measures (interaction effect of group and time: (t(6.00) = 2.28, p = 0.063) showed no statistical significance. In conclusion, when accessed by the Y-Balance test, minimalistic footwear may be more effective at improving dynamic balance, but not foot strength in comparison to conventional footwear.