Twitch/tetanus ratio and its relation to other properties of motor units.
The ratio of single twitch tension to maximal tetanic tension (Tw/Tet ratio) represents one of the physiological properties of single motor units. In our study, in agreement with the results of other studies, the mean Tw/Tet ratio of slow motor units was lower than that of fast motor units. But we found that the Tw/Tet ratios of the slow motor units with twitch tension between 0.75 and 1.5 g were higher than those of fast motor units with twitch tension in the same range. A significant linear relation between Tw/Tet ratio and twitch tension was obtained for the three types of motor units. This relationship could be due to the increasing number of muscle fibres within a motor unit with the twitch tension.
Celichowski
J
J
Department of Neurobiology, Academy of Physical Education, Poznań, Poland.
Grottel
K
K
D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009132:Muscles / Q000294:innervation* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar