Bitte aktivieren Sie JavaScript in Ihrem Browser um unseren Internetauftritt optimal nutzen zu können.

J Appl Physiol., 2002; 92(2): 469-78, PMID: 11796653

Energetics and mechanics of human running on surfaces of different stiffnesses

Jahr: 2002

Kerdok AE, Biewener AA, McMahon TA, Weyand PG, Herr HM
Harvard Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02138, Massachusetts. kerdok@fas.harvard.edu

Abstract

Mammals use the elastic components in their legs (principally tendons, ligaments, and muscles) to run economically, while maintaining consistent support mechanics across various surfaces. To examine how leg stiffness and metabolic cost are affected by changes in substrate stiffness, we built experimental platforms with adjustable stiffness to fit on a force-plate-fitted treadmill. Eight male subjects [mean body mass: 74.4 +/- 7.1 (SD) kg; leg length: 0.96 +/- 0.05 m] ran at 3.7 m/s over five different surface stiffnesses (75.4, 97.5, 216.8, 454.2, and 945.7 kN/m). Metabolic, ground-reaction force, and kinematic data were collected. The 12.5-fold decrease in surface stiffness resulted in a 12% decrease in the runner"s metabolic rate and a 29% increase in their leg stiffness. The runner"s support mechanics remained essentially unchanged. These results indicate that surface stiffness affects running economy without affecting running support mechanics. We postulate that an increased energy rebound from the compliant surfaces studied contributes to the enhanced running economy.

GID: 80; Letzte Änderung: 16.12.2007