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I must confess to being profoundly astonished by a recent list
posting (Joe Faust) regarding standardization of center of mass
locations in high jumping. While the reaction board method does
indeed yield a good estimate for the vertical mass centroid location
of a specific subject lying on the board in a well defined position,
a general standardization value of 56 % of the barefoot tallness for
ALL types of high jumpers must be regarded highly questionable. The
standardization of a value of 70.5 % of T (specified to an accuracy
of HALF A PERCENT!) for the vertical mass centroid location at the
moment of lift-off is really difficult to understand considering the
comparatively large variability in the body configurations at
take-off, in addition to the variabilities introduced by the
different body morphologies of the athletes.
H. Hatze, Ph.D.
Professor of Biomechanics
University of Vienna
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posting (Joe Faust) regarding standardization of center of mass
locations in high jumping. While the reaction board method does
indeed yield a good estimate for the vertical mass centroid location
of a specific subject lying on the board in a well defined position,
a general standardization value of 56 % of the barefoot tallness for
ALL types of high jumpers must be regarded highly questionable. The
standardization of a value of 70.5 % of T (specified to an accuracy
of HALF A PERCENT!) for the vertical mass centroid location at the
moment of lift-off is really difficult to understand considering the
comparatively large variability in the body configurations at
take-off, in addition to the variabilities introduced by the
different body morphologies of the athletes.
H. Hatze, Ph.D.
Professor of Biomechanics
University of Vienna
---------------------------------------------------------------
To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl
For information and archives: http://isb.ri.ccf.org/biomch-l
---------------------------------------------------------------