Self-arrest is perhaps the most important skill that we practice in snow school. The British Mountaineering Council put together a nice video on the self-arrest techniques that one should practice.
Though this video is quite good, there are a couple of things that we teach differently
It is breezed over in the video, but the best way to self-arrest is to avoid falling. Good snow climbing technique should be practiced on low-angle slopes so that when you are on high-angle slopes it comes as second nature.
We teach the piolet canne (cane) position as the baseline position. We only hold the piolet in the self-arrest position when it appears that a fall is likely. As the piolet canne position is the most stable walking position and it provides the most security, we like to see people move up the mountain in this position. One should practice self-arrest starting from the piolet canne position.
There is some debate on whether you should put your feet up or not. The concern -- as the guide in the video points out -- is that if you put your feet down and your crampon points catch, that you might flip head-over-heels. On the other hand, it might stop you more quickly. We teach people to put their toes into the snow to arrest the fall.
There is some controversy about whether to use a leash on an ice axe or not. Most of our guides choose not to use a leash on standard mountaineering routes like the Coleman/Deming on Mount Baker or on the Emmons Glacier on Mount Rainier .
Many people like wrist-leashes because they limit the possibility of dropping the axe. Our guides prefer them for steep terrain. There are two downsides to the constant use of a leash. First, it adds time to a turn, because the axe must be on the uphill side of your body. Moving the wrist-leash from one hand to the other many hundreds of times throughout the day adds time to the clock. Second, if you fall and lose control of the axe, it may become a liability. The last thing that you want in a fall is to be punctured by the axe.
Some people like to attach the ice-axe leash to their harness. This is a very bad place to attach a leash. Any loss of control during a fall could lead to a catastrophic torso puncture injury.
People are very adamant about wanting to use a wrist-leash while climbing for fear of dropping the axe. But really, how common is it for a climber to drop an axe? Not common at all. An ice axe is like a mountaineer's weapon. How many soldiers in the heat of battle drop their weapons? While mountain climbing is definitely not as intense as a war, it can be a dangerous pursuit and most climbers are unlikely to drop the most important tool they carry.
In preparing this blog, I watched a number of videos about self-arrest techniques. There were quite a few bad examples and indeed, some that were just flat dangerous. If you practice self-arrest, always wear a helmet and do not attach the leash of the axe to yourself. Always practice in a place where there is a good run-out. And be conservative in your practice of the head-first/stomach technique as this is a very easy one to get hurt practicing