Research article summary (published 30 Aug 2006):

The effect of lower extremity fatigue on shock attenuation during single-leg landing.

Full Abstract

BACKGROUND: The forces that are imposed on the body due to landings must be attenuated primarily in the lower extremity. Muscles assist in the absorption of these forces, and it has been shown that a fatigued muscle decreases the body's ability to attenuate shock from running. The purpose of the study was to determine the effect of lower extremity fatigue on shock attenuation and joint mechanics during a single-leg drop landing. METHODS: Ten active male participants were recruited (eight used for analysis). Each participant took part in a fatigue landing protocol. This protocol included cycles of a drop landing, a maximal countermovement jump, and five squats, repeated until exhaustion. Accelerometers attached to the skin measured tibia and head accelerations. Lower extremity kinematics were collected using an electromagnetic tracking system and kinetics were collected using a forceplate. A repeated-measures ANOVA (P<0.05) was performed on each of the dependent variables across the cycles of the fatigue protocol. FINDINGS: Fatigue was induced, however there was no significant change in shock attenuation throughout the body. Hip and knee flexion increased and ankle plantarflexion decreased at touchdown with fatigue. Hip joint work increased and ankle work decreased. INTERPRETATION: This change in work distribution is thought to be a compensatory response to utilize the larger hip extensors that are better suited to absorb the mechanical energy of the impact. The results suggested that the lower extremity is able to adapt to fatigue though altering kinematics at impact and redistributing work to larger proximal muscles.

Author information

Author/s: Coventry, Evan (E); O'Connor, Kristian M (KM); Hart, Barbara A (BA); Earl, Jennifer E (JE); Ebersole, Kyle T (KT);

Affiliation: Neuromechanics Laboratory, Department of Human Movement Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Clinical biomechanics (Bristol, Avon) (Clin Biomech (Bristol, Avon)), published in England. (Language: eng)

Reference: 2006-Dec; vol 21 (issue 10) : pp 1090-7

Dates: Created 2006/11/06; Completed 2007/01/04; Revised 2008/11/21;

PMID: 16949185, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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MeSH headings (categories)

This article was linked to the MESH Headings shown below.

Acceleration Adaptation, Physiological - physiology Adult Energy Transfer - physiology Humans Lower Extremity - physiology

Male Muscle Fatigue - physiology Muscle, Skeletal - physiology Physical Endurance - physiology Postural Balance - physiology Stress, Mechanical

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