Make sure the proper axis is using the proper morph
Uncheck the axis you don�t need and set up the morph values you took note of earlier.
Two things to keep in mind here, you maybe have to switch the max/min values of the rotation is negative. (Like my example here) and you will probably also have to pad the values a bit to keep it from hitting the 0 and 100 mark.
All ready to go, nice bicep and elbow
And now the morph is at 0, the arm looks just like how I modeled it at the rest pose.
There you go. Easy corrective morphing in Lightwave 7.5