I have this problem with the ring finger:
If I am going to do a middle barre', for example on the fifth fret, and I try to reach the seven fret on the high E, with the ring finger, the two fingers tend to make a triangle and I can't put them vertical and parallel. (I really hope to gave the idea!)
I have to use the right hand to rotate the ring finger but I can't stay in that position more than few seconds.
Any tips to improve this ?