European Journal of Applied Physiology

, Volume 113, Issue 6, pp 1395–1403

Muscle–tendon interaction and EMG profiles of world class endurance runners during hopping

Authors

    • Osaka University of Health and Sport Sciences
  • M. Ishikawa
    • Osaka University of Health and Sport Sciences
  • A. Nobue
    • Osaka University of Health and Sport Sciences
  • Y. Danno
    • Osaka University of Health and Sport Sciences
  • M. Akiyama
    • Osaka University of Health and Sport Sciences
  • T. Oda
    • Hyogo University of Teacher Education
  • A. Ito
    • Osaka University of Health and Sport Sciences
  • M. Hoffrén
    • Likes Research Center, University of Jyväskylä
  • C. Nicol
    • Aix-Marseille University
  • E. Locatelli
    • International Association of Athletics Federations
  • P. V. Komi
    • Likes Research Center, University of Jyväskylä
Original Article

DOI: 10.1007/s00421-012-2559-6

Cite this article as:
Sano, K., Ishikawa, M., Nobue, A. et al. Eur J Appl Physiol (2013) 113: 1395. doi:10.1007/s00421-012-2559-6

Abstract

The present study examined the muscle–tendon interaction of ten international level Kenyan runners. Ultrasonography and kinematics were applied together with EMG recordings of lower limb muscles during repetitive hopping performed at maximal level. The ten Kenyans had longer gastro Achilles tendon at rest (p < 0.01) as compared with ten control subjects matched in height. Conversely, the stretching and shortening amplitudes of the tendinous tissues of the medial gastrocnemius (MG) muscle were significantly smaller in the Kenyans than in controls during the contact phase of hopping. This applied also to the fascicle length changes, which were smaller and more homogeneous among Kenyans. These limited musculo-tendinous changes resulted in higher maximal hopping height and in larger power despite their reduced body weight. The associated finding of a greater shortening to stretching ratio of the MG tendinous tissues during contact could imply that the Kenyan MG muscle–tendon unit is optimized to favor efficient storage and recoil of elastic energy, while operating at optimal muscle fascicle working range (plateau region).

Keywords

Stretch-shortening cycle Elastic energy Running economy Ultrasound Stiffness

Copyright information

© Springer-Verlag Berlin Heidelberg 2012