Kinesiology, Vol. 37 No. 2., 2005.
Original scientific paper
Age-related changes in contractile properties of plantar flexor muscles in physically active women
Saima Kuu
Jaan Ereline
Helena Gapeyeva
Ivo Kolts
Mati Paasuke
Abstract
Twitch contractile properties of the plantar flexor muscles were compared between the groups of women of the 3rd, 5th, 6th and 8th decade participating in regular recreational physical activity. An isometric twitch was evoked by supramaximal electrical stimulation of the tibial nerve in the popliteal fossa by a rectangular pulse of 1 millisecond duration. A significant decrease was found in the twitch peak force, the maximal rates of force development and relaxation from the 6th decade onwards. A significant prolongation in twitch contraction time was observed from the 5th decade onwards. The 3rd decade group showed a significant postactivation potentiation, while the three older groups did not. No significant age-related changes were observed in the isometric twitch peak force and voluntary strength ratio, and the twitch half-relaxation time in women participating in regular recreational physical activity. It was concluded that the marked decrease in twitch force-potentiation and prolongation of the contraction time of the plantar flexor muscles in physically active women seem to begin after 40 years of age, while a reduction in the maximal voluntary and twitch force-generating capacity, and twitch contraction kinetics occurs after 50 years of age.
Keywords
ageing; human skeletal muscles; isometric twitch; physical activity
Hrčak ID:
4125
URI
Publication date:
23.12.2005.
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