backing out of the trailer

Hey guys!
Ok here is the issue
My horse won't back out of the trailer, we had him do it once, but it took 5 people and two lead ropes, and it was very dangerous, the only way I can get him out of the trailer is to lead him out and the other day he almost fell so
When you try to back him out he steps to the side and actually pinned my cousin to the side of the trailer once, and hurt my uncles arm another time, he is very hard to take places and he rarely goes anywhere which means I don't get to go anywhere either,
He will back off the wash bay and step off backwards, but he wont step backwards out of the trailer, I think its because he can't see what he is stepping on to but I don't know how to get him to realize its ground
So what can I do? Has anyone had a horse with this issue? If so, what did you do to ger him/her out of the trailer?
Thanks!

I'm not sure what type of trailer you have but if you have a center divider you could take it out and let him turn around to go out. If not I would just leave him in there with no food till he decides to come out. Leave him alone for an hour or 2 and see what happens. Once he comes out put him right back in.
Another thing to try. If you can't for safetys sake get in front of him to tap his chest or do other backing cues, you might try getting a long rope around his chest or driving reins on his halter. Then stand behind him outside the rear of the trailer and give the back cue. Take your time and don't get upset. If you have a sursingle it would be a good idea to put one on before loading to help keep the driving reins in place. Once the horse is out do it again and again. Hope this helps.

What type of trailer you have would be helpful to know (slant loads unload differently than stright :) )

If you're using a straight load trailer, i've always used a lungeline attached to the halter, and run it back to the "exit point". Ask him to back out, and I find that if you place your hand on their rumps (not a smack or anything, just resting there), most will realize that's the cue to back out. Of course, you may have to encourage him by gently pulling on the lunge line, but eventually, he'll get it. After he comes off, reward and repeat.

Vida also had great advice... :)

I agree with the driving reins. That's how I've taught a couple of horses to back out. First, though, make sure they understand to back when they are not in the trailer. Then get them in the trailer with it in a spot where they have the lowest drop off possible. Then attach the driving reins to either side of the halter, and ask them to back, making sure that they stay straght at all costs. It may only be one step at a time, and it will take a while, but every step they take ease up on the pressure, and let them stand for a second, and talk to them. Then ask for another step back. For me, whenever they get to where they are fixing to step off, I start saying easy as a way to cue them in that there is something behind them. It won't make any difference initially, but after a while they will figure it out and start feeling for the drop-off when you say it. Be prepared to use the driving reins or lunge lines for a long time, because this is a hard habit to break, but one that has to be. Best of luck with it.

The trailer he gets hauled in is a stock trailer
Ok ill try some of those, I also had another idea come to me last night that I could try which includes telling off my uncle, so ill try that one if these ones don't work lol
With the driving reins we did that with two lead ropes, but it took two people on each lead rope and one person pushing on his chest on the inside and my horse was so scared he was wet when my uncle shoved him out of the trailer I was jumpy so I know he must have been scared out of his wits
Thanks guys!

Our first trailer was a step down trailer and our new one has a ramp. When we first got it the horses loaded great but had a hard time backing down the ramp. It really helped them when one of us would stand to the side and encourage them saying "back" and then "easy" when they got to the ramp. Fras wanted to back down sideways and I started just holding my hand where she could see it to keep her from stepping off the side. They are both used to it now but the first few unloadings where a little scary. It does take time and patience so its something you want to work on when your not going someplace. Good luck, I'm sure you will get it down like an old pro. :)

Since you said he backed out of the wash rack fine I would train him in the wash rack when you back him up by saying back , back,back and then when he needst o step down off the rack even tho its not a big a drop as a trailer say step, step .step then carry that over to the trailer

OK. Here is what I did to teach my horse to back up (that was a trainer's suggestion). We taught her to walk in and back up from stall. Sounds like an easy thing to do. :) But(!) she completely freaked out when the trainer tried to back her out of stall: didn't want to go, tried to jump on top of him and so on (took us 5 mins to BACK her out the stall). Took an hour to make her walk in stall, stand, back out quietly. Next day I made stall more narrow imitating the trailer (put barrels along the wall). And again made her walk in, and then back out when I wiggled the rope slightly. In any case it was preparation for the trailer, which was just safer for both of us - me and horse, than trying same thing in trailer.

I would reccomend doing some in-hand trail work. Back the horse over tarps, poles, etc. My horse didn't know how to unload when he was a baby...I did a lot of ground work and taught him to pick up his hind feet when I said "step." 13 years later...I still have to say "step" or he won't put that 1st foot down out of the trailer...he will just look around at me like "is it safe!" But as soon as I say the word he comes on down perfectly.

Kitten val, that's a very good suggestion!