We are looking for a dynamic (or even a quasi-static?) biomechanical
model which integrates force plate information with motion analysis
data to determine joint forces and moments, particularly about the
L5/S1 region. We are using two force plates, with one foot on each
plate. Does anyone have a model that they would be willing to share
with us or know of a good, inexpensive commercially available model?

We also are looking for references or advice on how to determine the
location of the L5/S1 center of rotation from our markers. We have
placed markers on the skin over all major joints, including the L5
spinous process, the anterior superior iliac spine, and on the skin
over the left and right greater trochanters. Any information would
be greatly appreciated. Thanks in advance!

Chris Hamrick and Sean Gallagher
U.S. Bureau of Mines
Pittsburgh Research Center
P.O. Box 18070
Cochrans Mill Road
Pittsburgh, PA 15236

ph: 412-892-6673 (Chris) or 412-892-6445 (Sean)
fax: 412-892-6567
e-mail: hamrick@ergoserv1.usbm.gov or gallagher@ergoserv1.usbm.gov