View Full Version : RE: ICR debate

unknown user
06-18-1991, 11:41 PM
Dear biomecha(cli)nicians,

In response to Tom Cahalan's request, here is the summary of my standpoint
in the ICR debate.

1. When estimating internal forces from kinematic/kinetic data, use the
ICR as the reference point for moment calculations. You do this
automatically for the muscle and joint forces, when using the correct
methods. So, you must also do it for the external (ground reaction) forces.
The moment equilibrium equation requires that all moments are calculated
with respect to the same point.

2. When using kinematic/kinetic data to calculate net joint moments, forces
or powers, use a reference point that is close enough to the ICR so as not
to hamper the (clinical) interpretation. In practice, you would use a
point where you can reproducably attach a marker for the kinematic analysis.
Here, standardization, reproducability and ease of use is more important
than mechanical correctness.

That's it; short and (I hope) clear.

-- Ton van den Bogert, University of Utrecht