We teach self arrest a lot.
You could argue that we teach this skill more than any other. Every single course that goes out onto a glacier will spend at least some time covering this foundational skill. Some will spend all day, whereas others may only spend a short period of time. But it happens on just about every mountaineering trip...
There are a lot of different elements to a successful self-arrest and this particular post wasn't written to address them all. Instead, this post was written to discuss the one area of self-arrest where there is a fair bit of contention: toes up or toes down.
One school of thought is that when you arrest, you need to kick your toes up off the ground. This is so that if you are wearing crampons, they won't catch and flip you over.
The second school of thought is that you should kick your toes into the snow to help arrest the fall. In this school of thought, your toes should go in immediately to provide more resistance to the slide. However, this school also believes that you should only do this if you are not wearing crampons. This school believes that you should not kick your toes in if you are wearing crampons for fear of injury or flipping over.
The third school of thought is that you should always kick your toes into the snow, regardless of whether or not you are wearing crampons. The theory here is that stopping is the most important thing and that it's worth the risk of getting flipped over or injuring your ankles to stop.
Most AAI guides teach a combination of the second and third schools of thought. Programs that teach the first concept are definitely in the minority these days. The number one focus of any self-arrest activity is to stop a slide and most of the time, that means using your feet as part of the arresting system.
The real question comes when we look at the most obvious break between the second and third schools of thought. In the second, you kick your feet up while wearing crampons and in the third, you put them into the snow no matter what. Each of these styles of thinking are a little bit too rigid. In alpine climbing there are seldom absolutes. Both concepts have validity in one venue or in another. The problem is that it depends on snow conditions.
If you are on hard, solid ice or neve, then it's usually better to kick your feet up into the air. If you are on semi-solid terrain with occasional harder sections, then it's probably better to kick your toes in. This "it depends" approach isn't what most people want to hear. They want to hear a black and white answer; in part because a black and white answer is easier to remember in the heat of the moment.
Strategical thinking when moving in the mountains, in any kind of terrain, should always be composed of two questions. What is is the likelhood of a fall? And, what are the consequences of a fall? If these questions are always at the forefront of your thinking, then a black-and-white answer may not be so important. If you are constantly strategizing what you'll do in the event of a fall, then it is likely that you will react appropriately when the right skill is needed.
There is no easy closure on this question. There will always be people who argue vehemently for one of the three schools of thought. When all is said and done, none of the arguments matter. All that matters is that you can stop yourself when you fall.
--Jason D. Martin