If you are a lower limb amputee, these might just be the two most important things you can learn. Honestly, I think they're even more important than learning to walk on prosthetics, 'cause if for some reason you never actually do walk again, or just while you're learning or waiting to learn and still using crutches or a walker, you still might find yourself in situations where you can fall. You can even fall out of a wheelchair.
I didn't need to learn to fall. Not only am I a big klutz who used to fall all the time everywhere I went on dry land with my two original legs intact, but I ice skated for years when I was a kid and falling safely is something they taught me right off the bat. Higgy, a farm girl, ACA member, and frequent poster at Lady Amp's message board, says it's the same when you learn to ride horses. However, if you don't have either of these or anything similar (like skiing or dancing, for example) in your background, listen up.
The very best way to learn to fall if you don't already know how is to ask your physical or occupational therapist to teach you. He or she can take you to a place where there's lots of padding on the floor and you can go over it and over it under his or her supervision until you have skill and confidence. He or she can also teach you to get down onto the floor gently and to get back up from the floor on your own power at the same time. If you leave it up to others to volunteer instruction in these topics, you might never learn them. You may have to ask for instruction specifically and directly sometime during the course of your rehab. If you are a recent amputee but well enough to be learning to walk again, it's time. Don't wait.
Not everyone has a physical or occupational therapist or access to one at will, and not every therapist knows how to teach this. Also, for all I know you might be past needing any therapy and yet still not know how to fall safely and get back up on your own power. In case one of these scenarios reflects your reality, I will try to describe the process I use to the best of my ability.
Falling: Find or create a soft place to practice. Heap cushions on the floor, go to a place full of soft sand like an empty playground sandbox or a very soft, clean beach, or go out into the barn and use a giant pile of hay (pitchfork free, of course!). If you can, have someone physically strong hang out with you to supervise and help you (or to call 911 if something goes terribly, terribly wrong).
Take a few deep, slow breaths. Relax. Remember, you are choosing this and you are in control -- and even if you're not, you're going to land on something soft and not hurt yourself. Then just kind of let it happen. Tell your companion to push you unexpectedly if you have to, but once you're falling, once you're committed to downward motion, just let go and allow yourself to fall.
This is the most important thing to remember. Do not flail. Do not stick out an arm to try to break your fall. If you do, you are likely to sprain or break your finger, hand, wrist, arm, shoulder, etc. (not here so much, not if you've prepared your surface well, but definitely out in the world, in real life, on pavement for example). Do not try to break your fall with your missing leg and end up landing on your stump instead. It will hurt like blue blazes if the cut is recent and can cause terrible damage in any event. Of course, your instinct will be to try all of these things. This is why you must try to practice doing it right in a safe environment until you have habits which can override these instincts.
You don't have to just fall on whatever's facing the ground, though. As you are descending, try to kind of roll into your fall. Each of us is built differently, but some of us, especially we, um, shapely women, are endowed with built-in cushioning. Yeah, I do mean your butt. You don't want to land on your hip or your tailbone if you can avoid it, but you can control where you land by relaxing as you fall and just rolling into it. If you are a left-leg amputee, maybe try to roll so that you land on your right buttock and thigh, and vice versa of course if you are a right-leg amputee.
At first this will seem very difficult, especially if part of how you got your limb amputated involved a head injury. Panic is natural but can slow your mind as much as a concussion, so remember to breathe and try to relax. Also, as someone once told me, "When I fall, it happens so quickly that I don't have time to think about it." It's okay. If you are relaxed, you are less likely to sustain injury. Also, again, the purpose of this exercise -- and of practicing this exercise, over and over again -- is to make proper, safe falls habitual so you don't have to think about it when faced with one which comes as a surprise. When you know what you're doing, or even just when you can stay calm, time expands and you can see your choices, make plans, and direct your own actions much better.
Getting Back Up: I am only missing one leg and have no other injuries, I have great balance, and I am very, very strong, so getting back up is very easy for me. People with one or more other injured limbs or with some kind of debilitating condition will have a tougher time. However, if you ever want to be independent -- and that really is your choice -- practicing your balance, building your upper body strength, and learning to get yourself up off the ground all by yourself whenever you want are things you are just going to have to do. It's not just about falling. Think about all the fun things we do on the floor, on the grass, on our hands and knees (erstwhile as they may be). How will you weed your garden if you can't sit on the ground because you won't be able to get back up again on your own? How will you be able to lie on your stomach in front of the fireplace drinking wine with an attractive member of the opposite sex? What if you want to eat dinner at a traditional Japanese restaurant with low tables on the floor? See what I'm saying? This is something you've just got to figure out, build strength for and practice in order to be free and have a rich life.
Something to learn before getting up and besides falling is how to get down gently. I had to ask her specifically to teach me this, but my PT (who has something like 40 years of experience with amputees) had me start from the living room couch and practice next to it until I was strong enough not to need the couch to help me get up. To do this on your own, select a piece of furniture like a couch which is kind of low to the ground. Build "stairs" out of cushions next to the seat you will start from. Then you can sit down and just slip your bottom from your seat down to the floor in gentle stages, undramatically and painlessly. Make sure you've chosen a piece of furniture which is stable enough to support your weight while you practice rising.
On the ground? Good. Now kind of roll over onto your sound knee. You will not be using your amputated side at all for this process. Using only your sound leg and both hands/arms, get yourself into a position like a sprinter, so that you have three points of support off the ground, two hands and your sound knee or foot. Simultaneously transfer your weight onto your sound foot while rising. If you lose your balance, either let yourself fall by rolling back onto your bum on the sound side (recommended) or grab onto the couch for support if you don't have that much control. In fact, if you are nervous about going straight to your sound knee, practice rolling over so that your torso is supported by your hands on the couch, not the floor, then gradually adapt to doing this on the ground, away from the couch. It's actually easier to do it all on the ground once you have the hang of it.
If you have good balance on your sound leg, and if it is strong, you may actually find it easier to do this without your prosthetic on than while wearing it, because the prosthetic is a bit of dead weight. Of course, even if you're wearing a skirt or loose shorts, it might be impractical to expect to be able to take off your leg and put it back on at will in public. I asked to be taught how to do it before I even got my prosthetic, though, because I was spending most of my time alone at home after surgery and could envision myself falling and being unable to get up with no one around to help me, a stupid prospect. Also, if you don't have a strong whole leg and/or good balance, practicing this without your prosthetic on might be a good way to build both. Then the skills and strength will be there when you need them whether you're wearing your leg or not and whether you're able to take it off or not.
It's common for a person to simultaneously sustain injury to an arm on the same side of the body as a leg lost in an accident. You may be in this situation, trying to learn these skills before your injured arm has healed enough to support your weight. In this case, it is even more important for you to learn and practice in the company of someone strong enough physically to help you, preferably an experienced physical therapist.
Let's say you're missing an arm and a leg, though, either on the same or opposing sides. Or let's say you're healed but your arm is still kind of weak and no one did show you how to get up by yourself. Well...it's tough. And if you're still injured, it's a little dangerous because landing the wrong way can make your injuries worse. But it can be done safely; people in these situations do actually do it. I don't know how to do it without props of some sort. If anyone out there does, please post a comment or a link.
Using props, though, it's fairly easy. I've done it myself, deliberately holding one arm still. Practice next to your couch. You can balance yourself on your sound arm and leg while angling your residual limb and buttock up and onto the couch. Once you're seated this way, it's easy to just stand up, if standing is your goal. In "the wild," you would have to crawl or drag yourself up to something stable about this height (about a foot or a foot and a half) to accomplish the same effect.
Finally, if you do not have good balance or the limb or body strength to get yourself up without assistance, even once you have learned the mechanics, it would be wise to go about with a cane until you are stronger. A cane will not only help you avoid falls and brace yourself against falling. It can also serve as a prop to help you get up.
For those of you in the process of jettisoning all the extra accessories which come with traumatic injury, several companies make lightweight walking sticks for hikers which telescope, folding down to about a foot in length for storage, and which also have interchangeable tips, one cane-like and one more spikey like a ski pole for different types of terrain. If you stuff one in your purse (if you carry a big enough purse) or backpack or something, you will always have something you can lean on to get up, no matter where you are, and whether or not you are alone. You will also have a tool for helping you over rough terrain, and if you use two, you will be helping reduce strain on whatever joints you have left while also working your arms, a motion which can turn a vigorous walk into a truly aerobic exercise.
These types of walking sticks come with two types of handles, cane-like and ski-pole like. I'm not sure what the weight limit is, but I believe they can support someone over 200 lbs. You can find them or things like them at The Walking Company, REI, and L.L. Bean, among many other places. These companies also tend to carry things like short, fold-up tripod stools and other forms of low seating which you can stash in a backpack and use as hoisting props when you need them.
Get busy practicing! Get creative! Then, get out there! Just work hard and get your skills up so you won't ever have to be afraid to get down -- and then get back up again.