Ouch!

Running injuries are a part of running.  Nearly everyone whom I have run with this year has altered their running schedule based on some type of injury.  The 2011 Running USA National Runners Survey asked participants which injuries they've experienced in the last 12 months.  Blisters were the most common problem.  Knee complaints were the second most common injury.  These injuries were self-reported and did  not necessarily require medical attention.

Blisters	28.6%
Knee	22.3%
None	19.4%
Iliotibial Band Syndrome (ITB)	16.9%
Plantar Fasciitis	12.8%
Shin Splints	12.4%
Foot	12.1%
Hips	12.0%
Hamstring	9.8%
Calf	9.8%
Low Back	9.4%
Achilles Tendon	9.2%
Ankle	7.9%
Quadriceps	1.9%

A study in the British Medical Journal described the running-related injuries seen in a Canadian Sports Medicine Clinic from 1998-2002.  The study showed that knee injuries were the most common running-related injury when runners sought medical attention.