Changes in passive tension after stretch of unexercised and eccentrically exercised human plantarflexor muscles.
Exp Brain Res
; 193(4): 545-54, 2009 Mar.
Article
en En
| MEDLINE
| ID: mdl-19043681
ABSTRACT
The study measured the effect of stretch on passive mechanical properties in unexercised and eccentrically exercised plantarflexor muscles, to obtain insight into how stretch might serve athletes as a warm-up strategy. Passive torque, voluntary contraction strength and muscle soreness were measured before and after a large amplitude stretch given before and after a period of eccentric exercise and at 0, 1, 2 and 24 h later. Stretch of the unexercised muscle led to a 20% fall in passive torque which recovered within an hour. About 40% of the fall could be recovered immediately with a voluntary contraction. After eccentric exercise there was a rise in passive torque by 20% at 2 h post-exercise. This rise was postulated to result from an injury contracture in muscle fibres damaged by the exercise. It was accompanied by a fall in maximum voluntary torque and the development of muscle soreness at 24 h. Stretch of the exercised muscle led to a fall in passive torque and rise in pain threshold. It is proposed that in response to a stretch there is a fall in passive tension in the muscle due to stable cross-bridges in sarcomeres which could be recovered with a voluntary contraction and an additional component attributable to the elastic filament, titin. The size of the fall was not significantly different between exercised and unexercised muscle. These observations provide a physiological basis for the effects of passive stretches on skeletal muscle and help to explain why they are used as a popular warm-up strategy.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Músculo Esquelético
/
Ejercicios de Estiramiento Muscular
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Contracción Muscular
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Tono Muscular
Límite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Exp Brain Res
Año:
2009
Tipo del documento:
Article
País de afiliación:
Australia