European Journal of Applied Physiology

, Volume 83, Issue 4, pp 416–426

In vivo human triceps surae and quadriceps femoris muscle function in a squat jump and counter movement jump

Authors

  • Taija Finni
    • Department of Biology of Physical Activity, University of Jyväskylä, P.O. Box 35 (LL 227), 40351 Jyväskylä, Finland e-mail: finni@pallo.jyu.fi Tel.: +358-14-2602075; Fax: +358-14-2602071
  • Paavo V. Komi
    • Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, 40100 Jyväskylä, Finland
  • Vesa Lepola
    • LIKES-Research Centre for Sports and Health Sciences, 40100 Jyväskylä, Finland
ORIGINAL ARTICLE

DOI: 10.1007/s004210000289

Cite this article as:
Finni, T., Komi, P. & Lepola, V. Eur J Appl Physiol (2000) 83: 416. doi:10.1007/s004210000289

Abstract

An optic fibre method was used to measure in humans in vivo Achilles (ATF) and patellar tendon forces (PTF) during submaximal squat jumps (SJ) and counter movement jumps (CMJ). Normal two-legged jumps on a force plate and one-legged jumps on a sledge apparatus were made by four volunteers. Kinetics, kinematics, and muscle activity from seven muscles were recorded. The loading patterns of the tendomuscular system differed among the jumping conditions, but were similar when the jumping height was varied. Peak PTF were greater than ATF in each condition. In contrast to earlier simulation studies it was observed that tendomuscular force could continue to increase during the shortening of muscle-tendon unit in CMJ. The concentric tendomuscular output was related to the force at the end of the stretching phase while the enhancement of the output in CMJ compared to SJ could not be explained by increases in muscle activity. The stretching phase in CMJ was characterised by little or no electromyogram activity. Therefore, the role of active stretch in creating beneficial conditions for the utilisation of elastic energy in muscle was only minor in these submaximal performances. The modelling, as used in the present study, showed, however, that tendon underwent a stretch-shortening cycle, thus having potential for elastic energy storage and utilisation. In general, the interaction between muscle and tendon components may be organised in a manner that takes advantage of the basic properties of muscle at given submaximal and variable activity levels of normal human locomotion.

Key words Muscle mechanicsTendon forceMuscle-tendon interactionPowerOptic fibre

Copyright information

© Springer-Verlag Berlin Heidelberg 2000