Contribution of mono- and biarticular muscles to extending knee joint moments in runners and cyclists.
J Appl Physiol (1985)
; 94(6): 2241-8, 2003 Jun.
Article
em En
| MEDLINE
| ID: mdl-12533502
ABSTRACT
Motor actions are governed by coordinated activation of mono- and biarticular muscles. This study considered differences in mono- and biarticular knee extensors between runners and cyclists in the context of adaptations to task-specific movement requirements. Two hypotheses were tested 1) the length-at-use hypothesis, which is that muscle adapts to have it operate around optimal length; and 2) the contraction-mode hypothesis, which is that eccentrically active muscles prefer to operate on the ascending limb of the length-force curve. Ten runners and ten cyclists performed maximal, isometric knee extensions on a dynamometer at five knee and four hip joint angles. This approach allowed the separation of the contribution of mono- and biarticular extensors. Three major differences occurred 1) compared with runners, monoarticular extensors of cyclists reach optimal length at larger muscle length; 2) in runners, optimal length of the biarticular extensor is shifted to larger lengths; and 3) the moment generated by monoarticular extensor was larger in cyclists. Mono- and biarticular extensors respond to different adaptation triggers in runners and cyclists. Monoarticular muscles seem to adapt to the length-at-use, whereas biarticular muscles were found to be sensitive to the contraction-mode hypothesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Corrida
/
Ciclismo
/
Músculo Esquelético
/
Articulação do Joelho
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Appl Physiol (1985)
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Holanda