SLIP ON SNOW, INAPPROPRIATE EQUIPMENT/TECHNIQUE
Alberta, Rocky Mountains, Mount Lefroy
On the morning of July 7, 1990, a party of two were descending the west face of Mount Lefroy, unroped. While glissading, sitting and wearing crampons, one of them accelerated out of control. One of his crampons caught in the snow, flipping him over and fracturing his ankle. He then managed to self-arrest and was helped down to Abbot Pass hut by his partner. The injured climber was airlifted from the hut later that morning by the Banff Warden Service.
Ankle fractures are common in falls on snow and ice with crampons as they are not suitable for sliding. It is generally better to not wear them while glissading, since the use of feet is required for sliding and for self-arrest. (Source: Marc Ledwidge, Warden Service, Banff National Park)