Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Int J Sports Med ; 29(6): 512-8, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18027308

ABSTRACT

The higher oxygen consumption reported when shod running is compared to barefoot running has been attributed to the additional mass of the shoe. However, it has been reported that wearing shoes also modified the running pattern. The aim of this study was to distinguish the mass and shoe effects on the mechanics and energetics when shod running. Twelve trained subjects ran on a 3-D treadmill ergometer at 3.61 m . s (-1) in six conditions: barefoot, using ultra thin diving socks unloaded, loaded with 150 g, loaded with 350 g, and two shoe conditions, one weighing 150 g and another 350 g. The results show that there was a significant mass effect but no shoe effect for oxygen consumption. Stride frequency, anterior-posterior impulse, vertical stiffness, leg stiffness, and mechanical work were significantly higher in barefoot condition compared to shod. Net efficiency, which has metabolic and mechanical components, decreased in the shod condition. The mechanical modifications of running showed that the main role of the shoe was to attenuate the foot-ground impact by adding damping material. However, these changes may lead to a decrease of the storage and restitution of elastic energy capacity which could explain the lower net efficiency reported in shod running.


Subject(s)
Oxygen Consumption/physiology , Running/physiology , Shoes , Adult , Ergometry , Exercise Test , Humans , Male , Muscle Strength Dynamometer , Task Performance and Analysis
2.
Foot Ankle Int ; 19(11): 761-5, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9840206

ABSTRACT

This study was done to determine whether leg stiffness (Kleg) during running was related to rearfoot-to-forefoot angle in standing (RFAst) and running (RFArun). Footprints obtained from 32 subjects were used to calculate RFAst and RFArun, defined as positive when forefoot axis was abducted from rearfoot axis. A spring-mass model was used to calculate Kleg in running from ground reaction forces, measured by a force platform. The Kleg of runners (13.0 +/- 2.7 kN x m(-1)) was negatively correlated with RFAst (-8.4 degrees +/- 6.4 degrees) and RFArun (-0.4 degrees +/- 7.2 degrees). When runners were divided into opened foot (RFArun > 0; N = 19) and closed foot (RFArun < 0; N = 12) groups, the Kleg of opened foot runners was less than that of the closed runners. We suggest that foot structure is a factor responsible for the differences in leg stiffness observed in runners.


Subject(s)
Foot/anatomy & histology , Foot/physiology , Leg/physiology , Running/physiology , Adult , Biomechanical Phenomena , Dermatoglyphics , Elasticity , Humans , Male , Movement
3.
Foot Ankle Int ; 19(1): 32-7, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9462910

ABSTRACT

Factors making runners more susceptible to injuries were identified with a comparative study between a healthy control group (216) and runners (66) suffering from overuse pathology. On static and dynamic footprint, the angles alpha0 (static) and alpha1 (dynamic) between heel and forefoot have been measured. Analysis showed that the injured subjects have a more pronated foot than control group subjects. These results suggest that the pronating foot configuration would be an injury risk factor.


Subject(s)
Foot Injuries/physiopathology , Foot/physiopathology , Pronation , Running/injuries , Adult , Athletic Injuries/etiology , Athletic Injuries/physiopathology , Female , Foot/pathology , Foot/physiology , Foot Injuries/etiology , Foot Injuries/pathology , Humans , Male , Retrospective Studies , Risk Factors , Running/physiology
4.
Foot Ankle Int ; 18(3): 157-62, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9116896

ABSTRACT

The purpose of this study was to determine the possible mechanisms explaining the interindividual differences in foot orientations observed during running. Foot orientations, foot pressures, and ankle dorsiflexion and plantarflexion were simultaneously recorded on 12 male subjects running barefooted at 3.9 +/- 0.6 m.sec-1. The abduction of the forefoot was significantly related to the ankle dorsiflexion and plantarflexion velocities (P < 0.01 and P < 0.05, respectively). Because it was not possible, from pressure measurements, to determine differences in foot lever arm of runners, it is suggested that the interindividual variability of foot kinematics could not be explained by Bojsen-Møller's model, but could reflect differences in the lower limb stiffness control.


Subject(s)
Ankle/physiology , Foot/physiology , Movement , Running/physiology , Forefoot, Human/physiology , Humans , Male , Pressure
5.
Med Sci Sports Exerc ; 28(2): 225-32, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8775158

ABSTRACT

In this study, footprint and ground reaction forces (GRF) were simultaneously recorded from 32 male subjects running barefoot. Angle between the rearfoot and the forefoot in static (alpha S) and in running (alpha R) conditions, and orientation of both, rearfoot (alpha rf) and forefoot (alpha ff) with the direction of running (DOR), were measured and correlated to selected GRF parameters. The dynamic rearfoot/forefoot angle (alpha R) was correlated, positively with arch deformation (r = 0.58, P < 0.001), vertical Fz loading peak (r = 0.60, P < 0.001), mediolateral, and anteroposterior force rates (r = 0.47 and 0.48, P < 0.01), and negatively with stance time (r = -0.41, P < 0.05) and total course of the force application point path (r = -0.71, P < 0.001). Both a medial and a lateral rotation were observed on footprint between the rearfoot and the forefoot in the horizontal plane. A medially rotated forefoot ("closed foot") was associated to a rigid and inverted foot, whereas a laterally rotated forefoot ("open foot") was associated to a flexible and everted foot.


Subject(s)
Foot/physiology , Movement/physiology , Running/physiology , Adult , Biomechanical Phenomena , Humans , Male , Pronation
SELECTION OF CITATIONS
SEARCH DETAIL
...