<P> Because the offsets are relatively small in slalom, ski racers take a fairly direct line and often knock the poles out of the way as they pass, which is known as blocking . (The main blocking technique in modern slalom is cross-blocking, in which the skier takes such a tight line and angulates so strongly that he or she is able to block the gate with the outside hand .) In modern slalom, a variety of protective equipment is used such as shin pads, hand guards, helmets and face guards . </P> <P> Traditionally, bamboo poles were used for gates, the rigidity of which forced skiers to maneuver their entire body around each gate . In the early 1980s, rigid poles were replaced by hard plastic poles, hinged at the base . The hinged gates require, according to FIS rules, only that the skis and boots of the skier go around each gate . </P> <P> The new gates allow a more direct path down a slalom course through the process of cross-blocking or shinning the gates . Cross-blocking is a technique in which the legs go around the gate with the upper body inclined toward, or even across, the gate; in this case the racer's outside pole and shinguards hit the gate, knocking it down and out of the way . Cross-blocking is done by pushing the gate down with the arms, hands, or shins . By 1989, most of the top technical skiers in the world had adopted the cross-block technique . </P> <P> With the innovation of shaped skis around the turn of the 21st century, equipment used for slalom in international competition changed drastically . World Cup skiers commonly skied on slalom skis at a length of 203--207 centimetres (79.9--81.5 in) in the 1980s and 1990s but by the 2002 Olympic Winter Games in Salt Lake City, the majority of competitors were using skis measuring 160 cm (63.0 in) or less . </P>

Why do they hit the gates in slalom