wow, Oakleaf! here's a quote from that LATimes article:

"Injuries decimate runners. Studies indicate that about half of all runners are injured every year. The London-based Sports Injury Bulletin puts it at 60% to 65%. The cause? "The heel strike," says Santa Monica physical therapist Robert Forster, who provides videotaped running-form analysis at his training facility, Phase IV. "During running, you land with an impact of five times your body weight. When you land on your heel, the shock goes right into your joints. To lessen the shock, you have to land 'softer' -- and that means on your forefoot or midfoot with a bent leg, not on your heel with a straighter leg."