Ski poles (sometimes called "stocks") are used by skiers to improve balance, speed and acceleration. They probably evolved from walking sticks carried while traveling, and possibly from spears as well.
In the days before turning techniques had been properly developed, one long pole was normally used on sloping ground. The skier would lean or sit on the pole in order to increase friction with the ground, so slowing or stopping.
In modern skiing one pole is held in each hand, and each pole has a circular "basket" attached close to the lower end to prevent the pole sinking significantly into deep snow. At the upper end of the pole a strap is attached, which is normally slipped over the wrist to prevent the loss of the pole in the event of a fall. When skiing the backcountry (off piste) in trees, the wrist strap is not normally used, since there is a risk of wrist injury if the pole should catch on an unseen branch or root. You can also ski without poles as some freestyle skiers do.
Alpine skiers sometimes use poles as well. While they serve the same purposes as they do in cross-country, they can also help with the timing of the more advanced ski turns. By making contact with the ground between each turn in a process known as "pole planting", Alpine skiers are given greater stability as they move their mass down the hill, creating more acceleration and a tighter turning radius, but more force can be efficiently channeled down the arms onto the legs to allow for use of hands while skiing.
A ski pole is the correct length for Alpine skiing if, when placed tip to the ground at rest, the skiers elbow forms a right angle. Longer poles are used for cross-country to enable a longer thrust. Poles used for ski touring may be telescopic, so that they may be adjusted to suit snow conditions or the steepness of the slope.
Some racers in the high speed skiing disciplines (Giant Slalom, Super Giant Slalom, downhill, speed skiing) use curved poles that are bent to shape around their bodies while they are in a tuck position, in order to minimize air drag.
Ski jumping and skiboarding are the only varieties of skiing in which no poles are used. Ski poles were first used to test the snow you would be skiing over. That way you could get a rough mental picture of what you were skiing over. Now ski poles should be used as a timing device not for balance.
There are also more convenient alternatives to the traditional wrist strap - for instance "trigger" mechanisms that will come off in case of a crash to avoid injury.
There is some debate about what styles of poles should be allowed. Swedish skier Gunde Svan added more fuel to the debate by introducing the unipole. During summer training, he sat in a canoe and paddled upstream using two paddles. When he became tired, he switched to just one paddle and found that it was much easier, so he tested skiing using a single long pole. At the 1985 World Championships, he brought his homemade unipole and used it on a training day. Later the same day, the unipole was banned.
Wipo Publishes Patent of Rigat Marco for "Connection Assembly between a Ski-Pole and the Hand of the Skier" (Italian Inventor)
Jan 02, 2013; GENEVA, Jan. 2 -- Publication No. WO/2012/176053 was published on Dec. 27.Title of the invention: "CONNECTION ASSEMBLY BETWEEN A...
US Patent Issued to Lekisport on April 19 for "Ski Pole Basket Comprising an Adjustable Supporting Surface" (German Inventor)
Apr 26, 2011; ALEXANDRIA, Va., April 26 -- United States Patent no. 7,926,849, issued on April 19, was assigned to Lekisport AG (Baar,...