I was riding in a lesson last wednesday on a horse I have been leasing for a month. I've been riding him 2x a week, with one of those being a lesson, and having no problems. This past wednesday I was riding him in a lesson as usual. He seemed to be acting a little 'off'. He was being a little more forward than usual and 'jumped' forward at one point, I blamed that on a branch I heard crash behind us in the trail area. So, I was cantering poles and he was being a little fast. He went over the first pole and was getting too fast so I was going to turn him in a circle before the second one to slow him down a little. Only he swapped his lead over the first pole. I was turning him left and he was on his right lead, I couldn't turn right because there was a fence to a pasture there. So I didn't turn him too tight because I didn't want him to slip or fall since he was on the wrong lead. Before I could get him to turn completely, he took off across the field at a gallop. This horse is normally LAZY and needed a crop when I first started riding him or you couldn't get him to GO. So I was pulling back on the reigns trying to slow him and I heard my instructor say he was trying to change his lead but I was holding his reigns too tight, so I released them a little. All he did was speed up, so I grabbed up the reigns to give another go at getting him to STOP. When I did that he came to an abrupt halt which threw me forward, I recovered in a split second and sat back up but then he made a sharp turn to the right and took off at a gallop again and down I went. I hit the ground pretty hard...but it didn't seem too hard at first. I landed and looked up to see my horse galloping back to the barn with his head in the air neighing as loud as he could. I felt my neck was a little stiff, which has happened before when I came off. Just knocks my spine out of whack a little and it's sore for a couple days. They caught him and I got back on and just trotted a few circles and back over the poles (so he would know he couldn't get away with what he did). That night I didn't get much sleep because my neck was SO sore. I have bruises and scratches on my elbows and I think my helmet must have hit the bridge of my nose, which is now swollen and red. I've fallen before, as I mentioned, so this wasn't a big deal in that respect. BUT what has me a little concerned is that I wasn't even jumping. Just doing flat work. I normally jump. I'm just thinking that I'm getting older (34) and I don't bounce as well as I used too. I'm a little concerned that I might REALLY get hurt one time! My instructor said I should have tried to keep him in the 'area' we were riding in, rather than allowing him to gallop off as he did...not that it was my intention to do so. I don't really know who to 'blame' for this 'accident'. Partially I think my instructor should have seen that there was something 'off' with the horse and done something to prevent it from happening to begin with. I have since found out that this horse was sold and returned because the people who bought him said he was 'crazy'. Obviously it was MY fault for not being able to control him properly. My lease with him is over so I'll be back riding a different horse next week anyway. Any advice? Words of wisdom? Tell me it was a freak accident and I shouldn't be so worried!