Jack Hoffman lives for adventure. At 72, he fl ies airplanes, skis, and rides motorcycles and snowmobiles. He has hand-built houses, mined for gold in Alaska, and is currently restoring an antique gas pump. Over time, the cumulative impact of this “work hard, play hard” life has taken a toll on his back. He can’t point to a single injury that led to his years of back pain. “It just disintegrated,” Jack says.