I recently began to lease a 13 year old TB, retired from the track at 7, who has only been ridden intermittenly over the past 6 years with his current owner. The owner used to ride him 3-5 days a week but broke her back around 5 years ago and since then he has been ridden approx. 1 time a month by her husband or friend.
So basically...this horse has the basics but needs fine tuning and some getting in shape.
He apparently has done some eventing at the novice level back in the day, so I know that he is capable of jumping and has some dressage experience. Since I began leasing him 2 months ago I have been riding him ~4x a week and doing only flatwork. He has made major progress since then!
So my question is: What are some exercises I can do in the arena to continue to strengthen his hind end in addition to doing hills? Also, I have jumped him over a few oxers at 18" or so, but I am unsure of how much "getting in shape" he needs before I can actually start 'jumping' him over more than an oxer a day. The flat work I have been doing usually lasts 30 min a day and isn't too strenuous, but gives him a medium workout. Also, I should mention that he has a pre-existing stifle injury from 6 years ago that has been cleared with the vet with the advice to just strengthen with hills. When I am doing flat work his left stifle will occasionally 'give' at the canter, especially around a corner.
One more thing... at the canter he leans in and gets really low around the corners of the ring. Any advice as to how I can get him to straighten up and be collected? I try to keep my body upright and my weight in my outside stirrup to counteract this, but I am not sure if this is the correct thing to do.
Thank you all so much! I really appreciate any advice!