Knee Pain on Uneven Surface

I can train for half marathons on pavement and on trails, but as soon as I change it up to gravel or loose dirt my knee swells and the pain it causes is unreal. Any ideas why this happens?

Member Question

I can train for half marathons on pavement and on trails, but as soon as I change it up to gravel or loose dirt my knee swells and the pain it causes is unreal. I tried doing this a couple months ago and thought it was a basic knee injury, so I tried again yesterday and I was only able to run six miles before all the pain. Any ideas why this happens?

Answer by Sara Brown, DO
Member AMSSM

When running on uneven surfaces, the angle of your leg can change dramatically and put more pressure on the ligaments and meniscus (the shock-absorbing cartilage in between the bones of the leg).  In addition, gravel and loose dirt provide an unstable surface for foot strike, which may require greater work of the tendons that help to stabilize the knee joint.  Although you have not provided much information on your knee health, it is possible that running on loose dirt can result in degenerative tearing of your meniscus, which is associated with pain and swelling of the knee. 

Degenerative meniscus tears do not require surgery and often the associated pain and swelling resolves by simply avoiding aggravating activities. Other causes of your knee swelling could be a flare up of osteoarthritis or from tendinosis due to overusing the tendons in an effort to control motion at the knee.  Strengthening the muscles in your core and legs can help to stabilize the knee and dissipate some of the forces.

The research regarding risk factors for running injuries has shown an association between increased injuries in female runners who run on concrete. Other than that, there is no evidence linking training surfaces to running injuries.  In my clinical experience, I have not found a direct relationship between a certain running surface and increased injuries either.  Although, it does make a lot of sense that an unforgiving surface such as concrete would be harder on the body.

Sara Brown, DO
Chicago Primary Care Sports Medicine
www.chicagosportsdoctors.com

---

Reference:
Fields KB, Sykes JC, Walker KM, et al. Prevention of Running Injuries. Curr. Sports Med. Rep. 2010;9(3):176-182.