**"When the IK bends the knee, the value in the parameters actually does not change, the bending takes place more "behind the scenes". You cannot animate those hidden parameters, because there are no values to make keyframes of. And more than that, if you happen to have any dependent parameters derived from the numeric input parameters, those dependencies will not get evaluated when using IK or.....** **In general you should disable all of them for keyframes, except in some cases, like animating a robot figure with no dependent parameters or just a bunch of independent props."**

Thank you sir !
but I would add that this is definitely a shortcoming of posers faked implementation of IK and that a proper IK/FK solver, like the ones found in pro apps would always have keyframable track.

Cheerss

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