ISSN:
1439-6327
Keywords:
Aging
;
Reflex
;
Muscle contraction
;
Ankle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Contractile properties of the ankle plantarflexor muscles were compared between groups of young (¯x=26y) and elderly (¯x=82y) women. The H-reflex muscle contraction in the elderly group was characterized by a significant slowing of torque generation, as compared to the young women (means for average rate of torque development were young=0.16 Nm ms−1±0.02 (SE), elderly=0.09 Nm ms−1±0.02,P〈0.05). However, the proportion of the total motor unit pool activated by the reflex was similar for the young and elderly groups at 63% and 70%, respectively. Maximal voluntary isometric torques were significantly lower (71%) in the elderly (young ¯x=135.3 Nm±9.3, elderly ¯x=39.2 Nm±2.9,P〈0.01). These results are consistent with, and extend, previous reports showing decreased strength and speed of contraction in elderly muscle. Given that the average body weight was similar for the young and elderly groups, it was concluded that the aged plantarflexor muscles exhibited considerable impairment in ability to generate stabilizing torques about the ankle joint.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00643514
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