Dear Opensim experts:
I am now developing an ankle model with ligaments using Opensim. Have some confusion about the definition of force_length_curve. Could you please tell me what is the x value of the force_length_curve in the definition of ligaments (shown below)? Is it (L-L0)/L0 or L/L0, where L is the stretched length of the ligament, and L0 is the resting length, or is it any other definition?
<SimmSpline name="force_length_curve">
<x> -5 0.998 0.999 1 1.1 1.2 1.3 1.4 1.5 1.6 1.601 1.602 5</x>
<y> 0 0 0 0 0.035 0.12 0.26 0.55 1.17 2 2 2 2</y>
</SimmSpline>
Thank you very much in advance
Xijin