Abstracts Biological Sciences

Transitioning to minimal running footwear; implications for performance and running related injury when compared to conventional running shoes.

by Joe P. Warne

AIM: To investigate any changes in running economy or factors related to injury before and after a minimalist footwear (MFW) transition with gait-retraining when compared with conventional running shoes (CRS). INTRODUCTION: Recent interest in barefoot running has resulted in the development of a new footwear type which incorporates minimal cushioning and structural properties, in contrast with CRS. These MFW have been suggested to influence running kinetics and kinematics and may have a positive impact on performance and injury risk. However there is currently a dearth of scientific evidence available to support this theory. Of the limited research available the vast majority has only used acute comparisons between CRS and MFW, and has not considered the effect of “transitioning” into MFW over a period of time, with or without “barefoot” gait-retraining. METHODS: In all studies, effects for time (pre to post intervention), and condition (MFW vs. CRS) were evaluated, where participants were required to familiarise with MFW during the intervention. Study one examined changes in running economy (RE) with no feedback or gait-retraining, in contrast study two examined RE with deliberate gait-retraining included to the MFW transition. Study three investigated changes to plantar pressures and forces. Finally, study four evaluated kinetics and kinematics associated with injury. RESULTS: Following a MFW intervention, RE was found to improve 8.09% in MFW but not in CRS. However, when gait-retraining was included, no significant change in RE was observed over time. RE was significantly better in MFW compared to CRS irrespective of time (approx. 2.9% better in MFW). A MFW transition with gait-retraining was found to reduce plantar forces by 17.6%, loading rate by 33%, and the impact peak by 9%, which was not observed to the same degree in CRS. However, significantly higher plantar pressures and loading rates were observed in MFW when directly compared to CRS throughout testing. CONCLUSION: A MFW transition was found to significantly improve RE when gait-retraining was not included. However, gait-retraining may have a negative influence on RE. MFW and gait-retraining reduced impact variables over time. In addition, there was a reduction in plantar pressures under the heel, and no significant increase in pressures in the forefoot as a result of the intervention. With respect to condition, RE was better in MFW, but higher plantar pressures and loading rates were noted in MFW vs. CRS that may increase injury risk during this transition period.