View Full Version : maximum vertical GRF

John R. Hutchinson
09-20-2000, 02:42 AM

Alexander et al. (1979, reference below) used a simple
formula to estimate the maximum value of the vertical component of
the ground reaction force (at mid-stance) on a single limb of a
running quadruped:

F = (3.14159 * p * mass * g) / (4 * duty factor)

where p is the proportion of body weight that the limbs (fore/hind)
support. For a biped, of course, p would be 1; in most quadrupeds
fore and hind p would respectively be ~0.6 and 0.4.

Has anyone in the literature commented on this formula since
then, especially with revisions of the formula? Please reply
off-list and I can post a summary if it gets interesting. Thanks!

Alexander et al. 1979. Mechanical stresses in fast locomotion
of buffalo (Syncerus caffer) and elephant (Loxodonta africana).
Journal of Zoology 189:135-144.
John R. Hutchinson
Department of Integrative Biology Phone: (510) 643-2109
3060 Valley Life Sciences Bldg. Fax: (510) 642-1822
University of California
Berkeley, CA 94720-3140

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