The force-frequency relationship is altered in regenerating and senescent rat skeletal muscle
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Updated: Oct 28, 2026

Myo-mechanical Analysis of Isolated Skeletal Muscle
Published on: February 22, 2011
D R Marsh1, L R Hinds, W S Lester
1Department of Integrative Biology and Pharmacology, University of Texas Medical School, Houston 77030, USA.
Abstract:
Maximal tetanic tension was elicited at 200, 150, and 150 Hz in control tibialis anterior muscles and at 150, 100, and 100 Hz in 14-day regenerating muscles of young (3 months), adult (18 months), and old (31 months) Fischer 344/Brown Norway F1 rats, respectively. In contrast to young rats, increasing stimulation frequency from 50 to 150 Hz did not elicit significantly greater tetanic tension in control or regenerating muscles of old rats. At higher stimulation frequencies, tetanic fade was prevalent in control and regenerating muscles of adult (250-300 Hz) and old rats (200-300 Hz), but was only present at 14 days of recovery in regenerating muscles of young rats (300 Hz). The decreased efficacy of rehabilitative and physical medicine procedures in adult and elderly patients who have suffered skeletal muscle injury could be explained, in part, by the postulate that tetanic fade is indicative of inadequate synaptic transmission.
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