Hindlimb suspension inhibits air-righting due to altered recruitment of neck and back muscles in rats.
Jpn J Physiol
; 54(3): 229-42, 2004 Jun.
Article
em En
| MEDLINE
| ID: mdl-15541201
ABSTRACT
Effects of 9-week hindlimb suspension and 8-week recovery on air-righting reaction in response to drop from a supine position were studied in adult rats. The righting time in rats at the end of suspension (approximately 220 ms) was longer than the age-matched controls (approximately 120 ms, p <0.05). The unloading-related change in righting time was accompanied by lowered activities of electromyogram (EMG) and altered recruitment of both neck and back muscles at a specific stage of drop. After 8 weeks of reambulation, righting time recovered toward the control level (approximately 153 ms, p <0.05), but the EMG activity of back muscle was still less than controls. In contrast, the EMG of neck muscle during fall was even increased. The differences in the characteristics of the muscle fibers between two groups were minor. It is suggested that inhibition of recruitment, rather than the changes in the fiber characteristics, of neck and back muscles is one of the major causes of the slow air-righting.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Recrutamento Neurofisiológico
/
Dorso
/
Músculo Esquelético
/
Fibras Musculares Esqueléticas
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Elevação dos Membros Posteriores
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Movimento
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Contração Muscular
Limite:
Animals
Idioma:
En
Revista:
Jpn J Physiol
Ano de publicação:
2004
Tipo de documento:
Article