One of my favorite reads on Conformation is "Conformation, the relationship of form to function" by Marvin Beeman, DVM. It can be found on the AQHA website. It touches a lot on different conformation flaws in regards to what they can cause later on down life's road. In the case of being forward, it doesn't seem to be a huge deal according to him, especially not in comparison to the opposite. The way I understand him, horses that are over in the knee may seem shaky or week, but it isn't necessarily true and at least the knee is still bent in the direction it is meant to bend in. He also said it's preferred to calf kneed which puts the horses weight and power directly on the navicular bone causing slight calf kneed horses to be more prone than horses over at the knees. baby cinny.jpg
I was looking at the one and only foal picture I have of Cinny (the one on his registration) and even in that picture, though he isn't square and has his weight only on one foreleg, the leg the weight is on appears to be over at the knee to the same degree he currently is. I also know he has had one owner besides his breeder, and while owned by her he did pretty much nothing until I bought him at age 7. She had him broke to ride at 2, put him back in the dry lot, attempted to start riding him on trails in which he consistently and violently bucked her off so he sat another year until someone wanted to buy him.... me. So as for previous overwork, strain, etc.... unless you count chasing his brother around the dry lot, he hasn't really had any ha ha.
I brought him along slowly, ground work, ground work, ground work. Then walking under saddle, then trot, I don't think we even cantered until about 9 months after buying him except an occasional 3 or 4 strides he broke in to or just to see what he would do....but again, only a few strides. Mainly it was because he pretty much had NO balance. I bought him in April of 2010 and it took until Jan 2011 for him to really be balanced enough to carry out a nice, smooth, balanced canter.
My 12 year old wants to possibly use him hunter/jumper in a year or so, and I need to think about where the concussion and weight will end up when he lands on those knees. I think I may have to really limit her heights on him.