Are the knee and ankle angles at contact related to the tendon properties of lower limbs in long distance runners?

Keitaro Kubo,Naoya Tsunoda,Daisuke Miyazaki,Kenji Yamada,Shozo Shimoju

doi:10.1186/s40064-016-1797-1

Abstract

The purpose of this study was to investigate whether the knee and ankle angles at contact during running were related to the elastic properties of tendon structures in knee extensors and plantar flexors and performance in trained long distance runners. Thirty-two highly trained male long distance runners participated in this study. Elongation of tendon structures in knee extensors and plantar flexors were measured using ultrasonography while subjects performed ramp isometric contractions up to the voluntary maximum. The relationship between estimated muscle force and tendon elongation was fit to a linear regression, the slope of which was defined as the stiffness of tendon structures. Knee and ankle angles at contact during running were determined at a speed of 18 km/h on a treadmill. Knee and ankle angles at contact were not correlated to the stiffness of tendon structures in knee extensors and plantar flexors. In addition, the best official record in a 5000-m race was not significantly correlated to knee and ankle joint angles at contact. In conclusion, knee and ankle angles at contact were not related to the elastic properties of tendon structures in knee extensors and plantar flexor and the performance of long distance running.

Highlights

The foot strike pattern during running is receiving a lot of attentions among recreational and competitive runners (e.g., Lieberman et al 2010)
Previous studies showed that a higher percentage of forefoot strike runners, in which the ball of the foot contacts ground before the heel comes down, was observed among elite long distance runners (Hasegawa et al 2007; Kasmer et al 2013; Larson et al 2011)
We investigated whether the knee and ankle angles at contact during running were related to the elastic properties of tendon structures in knee extensors and plantar flexors and performance in trained long distance runners

Summary

Introduction

The foot strike pattern during running is receiving a lot of attentions among recreational and competitive runners (e.g., Lieberman et al 2010). Previous studies showed that a higher percentage of forefoot strike runners, in which the ball of the foot contacts ground before the heel comes down, was observed among elite long distance runners (Hasegawa et al 2007; Kasmer et al 2013; Larson et al 2011). Rearfoot strike runners, in which the heel first contacts the ground, were more economical than forefoot strike runners according to the other studies (Ogueta-Alday et al 2014; Williams and Cavanagh 1987). Perspectives on the effects of foot strike pattern on the running performance and economy have not yet been unified. Several reports have used ultrasonography to investigate the relationship between the tendon properties of lower limbs and the running performance and economy (Arampatzis et al 2006; Fletcher et al 2010; Kubo et al 2010, 2015a). Fletcher et al (2010) demonstrated that higher stiffness of the Achilles tendon

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