<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Dear Musculoskeletal
Modeling Research Community,</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">We would like to inform
you that the data for the Fourth Grand Challenge Competition to Predict In Vivo
Knee Loads has now been posted on the Simtk.org website (<a href="https://simtk.org/home/kneeloads" target="_blank">https://simtk.org/home/kneeloads</a>).
We apologize that we were unable to post the competition data sooner, but bugs
in the Vicon Nexus software prevented us from completing the data processing as
quickly as we had anticipated. The competition will be held at the 2013 ASME
Summer Bioengineering Conference in Sunriver, Oregon (<a href="http://www.asmeconferences.org/SBC2013/">http://www.asmeconferences.org/SBC2013/</a>).</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">The goal of the Grand
Challenge Competition is to advance the field of musculoskeletal modeling by
quantitative evaluation of model-based estimates of muscle and contact force in
the knee during gait by using in vivo tibial contact force data collected from
subjects implanted with force-measuring knee replacements. An overview of the
competition data, including the two gait cycles to be used for the fourth
competition, is contained in the file “Competition Data Description.pdf.” The
data for this year’s competition includes subject-specific geometric bone
models that span from the pelvis to the toes. Motion capture, ground reaction,
EMG, and tibial contact force data were collected while the subject performed
overground and treadmill walking under a wide variety of conditions. CT, strength,
and fluoroscopic data were also collected and will be released at a later date.
A subject-specific OpenSim model is currently in development and will be
released in approximately 2-3 weeks.</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Competitors who wish to
participate in the Grand Challenge Competition need to submit an abstract to
the 2013 ASME Summer Bioengineering Conference by January 11th, 2013. Competitors
will also submit their predicted medial and lateral tibial contact forces for
the specified gait trials. The contact force predictions will be submitted by
email to Allison Hall (<a href="mailto:allisonlhall@ufl.edu">allisonlhall@ufl.edu</a>)
by February 4th, 2013.</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">The research team
encourages others to use the data and models from all four Grand Challenge
Competitions for their own research, publications, and grant proposals. If you
use any competition data or models in any publications, please cite the
following journal article:</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Fregly, B.J., Besier,
T.F., Lloyd, D.G., Delp, S.L., Banks, S.A., Pandy, M.G., and D'Lima, D.D.
(2012) Grand challenge competition to predict in vivo knee loads. Journal of
Orthopaedic Research 30(4):503-513.</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">We hope to see broad
participation from the musculoskeletal modeling research community for this
year’s competition. Please post any questions you have about the competition on
the Public Forum of the Simtk.org competition website.</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Best regards,</font></p>
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<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Allison Hall, University
of Florida</font></p>
<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Darryl D’Lima, Shiley
Center at Scripps Clinic</font></p>
<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">Thor Besier, University
of Auckland</font></p>
<p class="MsoNormal" style="margin-bottom:0.0001pt"><font face="arial, helvetica, sans-serif">B.J. Fregly, University
of Florida</font></p><br>