ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

efore the joint moment reaches zero. It should be also noted that the fast changes in the
joint moment were modeled without allowing doublets and triplets to occur in MUs
(two or more impulses coming before refractory period, which is assumed to be equal to
the contraction time). This admission effectively limits the maximum contraction speed
of a muscle to the speed obtained by a simultaneous firing of all of MUs in the same
moment - (Fig.2, the upper right picture). So, changes of the joint moment with higher
speed then the one predetermined by the MUs' composition can be achieved only with
highly coordinated antagonist co- contractions.
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Acknowledgments. This study was partly supported by the Bulgarian National Science
Fund, Grant No. DMU 02/05 (ДМУ 02/5), and by the Bilateral Agreement between the
Bulgarian Academy of Sciences and the Polish Academy of Sciences.