Influence of the muscle-tendon unit's mechanical and morphological properties on running economy
| Autor: | Kiros Karamanidis, Gianpiero De Monte, Savvas Stafilidis, Gert-Peter Brüggemann, Gaspar Morey-Klapsing, Adamantios Arampatzis |
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| Rok vydání: | 2006 |
| Předmět: |
Adult
Male Physiology Video Recording Isometric exercise Kinematics Aquatic Science Running Tendons Oxygen Consumption medicine Cluster Analysis Humans Knee Aponeurosis Treadmill Muscle Skeletal Molecular Biology Ecology Evolution Behavior and Systematics Mathematics Analysis of Variance Skeletal muscle Anatomy Biomechanical Phenomena Tendon medicine.anatomical_structure Insect Science Running economy Animal Science and Zoology Quadriceps tendon Ankle Muscle Contraction |
| Zdroj: | Journal of Experimental Biology. 209:3345-3357 |
| ISSN: | 1477-9145 0022-0949 |
| DOI: | 10.1242/jeb.02340 |
| Popis: | SUMMARYThe purpose of this study was to test the hypothesis that runners having different running economies show differences in the mechanical and morphological properties of their muscle-tendon units (MTU) in the lower extremities. Twenty eight long-distance runners (body mass: 76.8±6.7 kg, height: 182±6 cm, age: 28.1±4.5 years) participated in the study. The subjects ran on a treadmill at three velocities (3.0, 3.5 and 4.0 m s-1) for 15 min each. The \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\dot{V}}_{\mathrm{O}_{2}}\) \end{document}consumption was measured by spirometry. At all three examined velocities the kinematics of the left leg were captured whilst running on the treadmill using a high-speed digital video camera operating at 250 Hz. Furthermore the runners performed isometric maximal voluntary plantarflexion and knee extension contractions at eleven different MTU lengths with their left leg on a dynamometer. The distal aponeuroses of the gastrocnemius medialis (GM) and vastus lateralis (VL) were visualised by ultrasound during plantarflexion and knee extension, respectively. The morphological properties of the GM and VL(fascicle length, angle of pennation, and thickness) were determined at three different lengths for each MTU. A cluster analysis was used to classify the subjects into three groups according to their \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \({\dot{V}}_{\mathrm{O}_{2}}\) \end{document}consumption at all three velocities (high running economy, N=10;moderate running economy, N=12; low running economy, N=6). Neither the kinematic parameters nor the morphological properties of the GM and VL showed significant differences between groups. The most economical runners showed a higher contractile strength and a higher normalised tendon stiffness (relationship between tendon force and tendon strain) in the triceps surae MTU and a higher compliance of the quadriceps tendon and aponeurosis at low level tendon forces. It is suggested that at low level forces the more compliant quadriceps tendon and aponeurosis will increase the force potential of the muscle while running and therefore the volume of active muscle at a given force generation will decrease. |
| Databáze: | OpenAIRE |
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