Effects of Maximalist vs. Minimalist Shoes on Kinematic and Kinetic Variables

Abstract

The objective of this study was to compare the effects of minimalist vs. maximalist (degree of cushioning of soles) shoes on cadence, impact force, and joint angles at toe off in runners. We hypothesized that maximalist shoes would have differential effects vs. minimalist shoes in terms of lower cadence, higher impact forces at foot strike, and lower amounts of ankle (plantar) flexion, knee extension, and hip extension in NCAA Division I cross-country runners. A high-speed (100 frames per second camera (Basler Pylon (Basler AG, Ahrensburg, Germany)) was utilized to record 2- dimensional kinematic data of knee, hip, ankle, and trunk movements/angles. A RunScribe device was also utilized to capture kinetic variables during the gait cycle recording measurements such as stride rate, stride length, contact time, foot strike type, impact peak forces (G's), braking Peak forces (G's), stance excursion, and pronation excursion of the two shoe conditions. Runners were assessed on a motorized treadmill, and for both maximalist and minimalist conditions the within-subject running speeds were held constant between 5 and 9 mph. There were several significant differences observed between maximalist shoes and traditional running shoes (racing flats). First, the amount of ankle plantar flexion at the moment of toe off was lower in the maximalist shoe compared to the traditional racing flat (p = 0.020). Second, the degree of knee flexion was significantly lower in the maximalist running shoe when compared to the traditional racing flat (p = 0.002). Third, trunk flexion at toe off, was significantly greater in the maximalist shoe condition compared to the traditional racing flat (p = 0.018), indicating a more upright posture at toe off in the traditional running shoe. The kinetic results of our study did not support our hypothesis as there were no significant differences in terms of stride rate or length, contact time, braking or impact forces, or other related measures between the two shoe variations. Furthermore, there was no significant ‘sex*shoe’ interaction in any of the kinetic or kinematic variables. In conclusion, in contrast to kinetic results, the kinematic results of the study supported the hypothesis that in order to accommodate impact forces in the ankle and hip, runners in the maximalist shoe condition utilized less range of motion as compared to less cushioned/minimalist racing flats.