Heath Woods doesn't get much business these days. A paramedic at Mount Snow in Vermont, he treats injured mountain bikers during the summer. Yet over a four-week stretch during which hundreds of riders braved the mountain's rocky woodland trails and craggy fields, he saw nary a soul. A few years ago, he bandaged half a dozen banged-up riders each weekend. Now, says Woods, 26, "the equipment is so much better, fewer riders are getting hurt."
Mountain-biking injuries have plummeted since the mid-'90s. About 48,600 people sustained such injuries in 1995, reports the U.S. Consumer Products Safety Commission. In 2001 the figure...