Abstract
To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running.
Citation: Wunsch T, Alexander N, Kröll J, Stöggl T, Schwameder H (2017) Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running. PLoS ONE 12(2):
e0172287.
https://doi.org/10.1371/journal.pone.0172287
Editor: Steven Allen Gard, Northwestern University, UNITED STATES
Received: August 5, 2016; Accepted: January 6, 2017; Published: February 24, 2017
Copyright: © 2017 Wunsch et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: This study was supported by adidas FUTURE Team, adidas AG, Herzogenaurach, Germany (www.adidas-group.com). adidas had no involvement in the collection, analysis, or interpretation of any data. None of the authors of this article has any conflict of interest. The results of the current study do not constitute endorsement of the product by the authors or the journal. Furthermore, we acknowledge financial support by the Open Access Publication Fund of the University of Salzburg.
Competing interests: Please note that the study was supported by adidas FUTURE Team, adidas AG, Herzogenaurach, Germany. adidas had no involvement in the collection, analysis, or interpretation of any data. The results of the current study do not constitute endorsement of the product by the authors or the journal. There are no patents, products in development, or marketed products to declare. This does not alter the authors’ adherence to all PLOS ONE policies on sharing data and materials. Therefore, none of the authors of this article has any conflict of interest.
Description
This study investigates the effects of a leaf spring structured midsole on running performance.