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The torque–velocity relationship in large human muscles: maximum voluntary versus electrically stimulated behaviour
journal contribution
posted on 2013-06-18, 13:51 authored by Matthew PainMatthew Pain, Fraser Young, Jinwoo Kim, Steph ForresterSteph ForresterThe in vivo maximum voluntary torque–velocity profile for large muscle groups differs from the in vitro
tetanic profile with lower than expected eccentric torques. Using sub-maximal transcutaneous
electrical stimulation has given torque–velocity profiles with an eccentric torque plateau ~1.4 times the
isometric value. This is closer to, but still less than, the in vitro tetanic profiles with plateaus between
1.5 and 1.9 times isometric. This study investigated the maximum voluntary and sub-maximum
transcutaneous electrical stimulated torque–angle–angular velocity profiles for the knee extensors and
flexors in a group of healthy males. Fifteen male subjects performed maximum voluntary and submaximum
electrically stimulated (~40% for extensors and ~20% for flexors) eccentric and concentric
knee extension and flexions on an isovelocity dynamometer at velocities ranging from ±50° s-1 to
±400° s-1. The ratio of peak eccentric to peak isometric torque (Tecc/T0) was compared between the
maximum voluntary and electrically stimulated conditions for both extensors and flexors, and between
muscle groups. Under maximum voluntary conditions the peak torque ratio, Tecc/T0, remained close to
1 (0.9 – 1.2) while for the electrically stimulated conditions it was significantly higher (1.4 – 1.7 ;
p<0.001) and within the range of tetanic values reported from in vitro studies. In all but one case
there was no significant difference in ratios between the extensors and flexors. The results showed
that even the largest muscle groups have an intrinsic Tecc/T0 comparable with in vitro muscle tests,
and it can be ascertained from appropriate in vivo testing.
History
School
- Sport, Exercise and Health Sciences
Citation
PAIN, M.T.G. ... et al, 2013. The torque–velocity relationship in large human muscles: maximum voluntary versus electrically stimulated behaviour. Journal of Biomechanics, 46 (4), pp.645-650.Publisher
© ElsevierVersion
- AM (Accepted Manuscript)
Publication date
2013Notes
NOTICE: this is the author’s version of a work that was accepted for publication in the Journal of Biomechanics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published at: http://dx.doi.org/10.1016/j.jbiomech.2012.11.052Publisher version
Language
- en