Pose distortion using AimSpace1D

I made three one frame animations for a simple aim space. The character blueprint has the look height being set by the mouse movement. I then pass that to the animation blueprint through a blueprint interface function. However, when it’s blended with the idle/run state, I get this:

http://imgur.com/IkLkdzA

This is the AimSpace1D:

http://imgur.com/Qg5MKrW

What did I do wrong to get my result? If it makes a difference, the idle/run is from the default UE4 guy, retargetted to my skeleton.