The stiff plate location into the shoe influences the running biomechanics

ABSTRACT

The changes in running biomechanics induced by an increased longitudinal bending stiffness (stiff plates added into the shoes) have been well investigated, but little is known concerning the effects of the stiff plate location into the shoe on running biomechanics. Fourteen male recreational runners ran at two participant-specific running speeds (3.28 ± 0.28 m/s and 4.01 ± 0.27 m/s) with two shoe conditions where a stiff plate was added either in high (under the insole) or low location (between the midsole and outsole). Ground reaction forces, lower limb joint angles, net joint torques and work, as well as alignment between the resultant ground reaction force and the leg were analysed. Among the running speeds performed by the runners, the high location significantly decreased propulsive ground reaction forces, increased metatarsophalangeal joint dorsiflexion and ankle plantarflexion, induced an increased alignment between the resultant ground reaction force and the runner’s leg, thus decreasing all the lower limb joint torques and the positive work at the knee joint compared to the low location. The results suggested that the high stiff plate location into the shoe should be considered for running performance perspectives, but care should be taken to not alter the perceived comfort and/or increase injury risks.

KEYWORDS:

• Footwear
• shoe design
• longitudinal bending stiffness
• running speed
• lower limb joint

Acknowledgments

Authors would like to thank Stéphane Charnet, Bao Kiet Phan, Thao Nguyen Diep Xuan and their teams (Kalenji, Decathlon) for their help during the design of the shoe prototypes. Authors also thank Dr Cédric Morio (Decathlon SportsLab) for all the discussions and advices provided concerning this study, and Mikku Knudsen (Decathlon SportsLab) for his English review of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.