Stress fractures are ridiculously common among runners, but this post will specifically address the apparent rash of metatarsal stress fractures afflicting minimalist and VFF runners, including myself.
First off, the term “barefoot” needs to be clarified. In every case I’ve found the runner wasn’t actually barefoot. We were all running in minimal shoes: Vibram FiveFingers, Nike Frees or something similar.
I noticed several consistencies among runners’ accounts of their injuries:
- Running in Vibram FiveFingers or other minimalist shoes, not barefoot.
- Running faster than normal (races, speed work, or just having too much fun)
- Mostly older than 35 years old (past the age of peak bone mass)
- Injury occurs months after transitioning to minimalist or barefoot running
So here’s my theory:
The majority of stress fractures affecting minimalist runners are not impact-related, but rather result from overloading weak metatarsals with increased toe push-off. These injuries arise several weeks or months after switching to natural running because the runner’s muscles strengthened faster than their bones.
Metatarsals are most susceptible to injury because they’ve been immobilized and weakened by conventional shoes. The second metatarsal, being the longest, endures the most stress.
Skin protection offered by VFFs and minimal shoes likely increases the risk of injury, friction on bare toes would have limited activity before the bones could have been hurt.
As I’ve been researching this, I’ve found a lot of stories similar to my own:
- Joe (me, 40 years old)
Proximal stress fracture of the second metatarsal after running much faster than usual in VFFs.
- Bob at Downtown runner (51 years old)
Second metatarsal stress fracture in VFFs during a short race while running at a personal record pace.
- Caitlin (34 years old)
stress fracture of the second metatarsal while doing speed work in Nike Frees.
- David Abel (mid-thirties?)
Second metatarsal stress fracture after running a very fast half marathon in VFFs.
- Elliot Fuller (age unknown)
Likely stress fracture after a fast VFF run. From his description, it’s another proximal second metatarsal injury.
- Curtis M (age unknown)
stress fracture in VFFs while doing speed work.
- Kristin (age unknown)
second metatarsal stress fracture in VFFs after a faster than normal 5k.
- Sherri Leimkuhler (age unknown)
Metatarsal stress fracture after running “a 5K race in one of my best times ever.” Sherri is the sports columnist at the Carroll County Times.
- Phil Hart (40+ years old)
Third metatarsal stress fracture after sprinting the last half mile of a short run in VFFs.
If you’re a near-barefoot, minimalist or VFF runner and have suffered a stress fracture, please email me or leave a note in the comments.