I have never been able to lower the heels on a mature horse with clubbed feet. Any time I tried, they went lame and we had to let them stand at their natural angle. I have a mare with an 80 degree angle on one foot. Her feet were normal until she was almost 2. She was briefly lame and from that point on, her right front got more and more clubbed looking. We had her x-rayed and she had a little rotation. Vet said to try lowering her heel and the instant she went lame we were to stop lowering her heel. Well, she went lame right away, so she has an 80 degree perfectly sound foot.
This mare has so many conformation problems, it is hard to say what caused what. I would say that the upright pasterns and clubbed feet are not related to the injury. When both feet are clubbed and both pasterns are that upright, it is usually from nutritional deficiencies during pregnancy and as a foal or are inherited from bloodlines known to produce bad legs and feet.
Her knees (or at least her left knee) is a poster child for an off-set cannon or bench knee as it is sometimes called. This is a major inherited conformation fault.