We spend quite a bit of page-space in Tread Lightly discussing the incidence and possible causes of barefoot/minimalist running transition injuries. Thus, it is with some interest that after reading Steve Magness’ recent post on studies presented at the annual meeting of the American College of Sports Medicine that I hopped onto the meeting website and came across the following presentation:
The abstract of the study, conducted by Allison Altman of the University of Delaware and Irene Davis from the Spaulding National Running Center at Harvard Medical School, reads as follows:
There are more than 16 million runners in the United States. Of these runners, up to 79% are injured each year. It has been suggested that an increasing number of runners are converting to barefoot running to avoid injuries by running with a softer landing pattern. However, the alteration in mechanics associated with this conversion may increase the risk of injury during the transition. PURPOSE: To determine the injury patterns associated with the transition from shod to barefoot running. METHODS: 109 barefoot runners were recruited from online advertisements. These runners were between 18-50 yrs and were running at least 10 miles/week. Injuries associated with barefoot transition were reported to a web-based survey. Injuries were divided into musculoskeletal injuries (MS_INJ) and injuries to the plantar surface of the foot (PL_INJ). MS_INJ were further divided into those that were professionally assessed where a clear diagnosis was noted, and those that were self-reported. RESULTS: 17% (18/109) of the runners sustained a MS_INJ during their transition with half of those (9/109) seeking medical attention. 15% (16/109) of barefoot runners sustained PL_INJ. 37 total injuries were reported, with 21 being MS_INJ, and 16 were PL_INJ. The most common MS_INJ were foot, arch, calf and lower leg pain. Of the PL_INJ, blisters were the most common. Cuts, thought to be a significant risk with barefoot running, only occurred in 2/109 runners. CONCLUSION: Overall, the occurrence of transition injuries was relatively low. Conditioning of the arch and lower leg muscles, coupled with a gradual toughening of the plantar surface of the foot should help to reduce these injuries during transition.
And below is the table showing the injury results:
Table 1. Injuries reported during transition to barefoot running.
|Plantar fasciitis||2||Pain on top of foot||4|
|Posterior tibialis strain||2||Achilles pain||2|
|Dorsal foot pain||1||Calf pain||2|
|Fibular stress fracture||1||Shin pain||2|
|Gastroc-soleus strain||1||Arch pain||1|
|Metatarsal stress fracture||1||Total (#injuries/#runners)||11/9|
|Ankle joint impingement||1|
|Iliotibial Band Syndrome||1|
|Plantar Surface Injuries||#INJ|
Now, it’s important to note that meeting abstracts such as the one above are necessarily short, don’t provide a lot of information regarding methodology, and are not equivalent to a peer-reviewed journal article. As such, extreme caution is warranted when it comes to interpretation. But, the results of this study are rather interesting, and I suspect will be fodder for some interesting discussion and debate.
Almost every time I read a news article about barefoot running I see a quote from a medical professional claiming that they are seeing something equivalent to a wave of “barefoot running” related injuries. I put barefoot running in quotes because it’s very difficult to distinguish whether they are talking about people getting hurt while actually running with nothing on their feet, or whether these injuries are occurring in people wearing “barefoot-style” shoes, or even just one particular type of “barefoot-style” shoe. This, to me, is a very important distinction, and is why I hate it when the word barefoot is misused. Barefoot means nothing on the feet. Period.
Now, if I had to guess, and this is totally speculation since I have no data to support this, most of the injuries seen in clinics are probably occurring in people running in barefoot-style footwear. Why? A couple of reasons. First, if my observations at races over the past few years are representative of anything, there just aren’t that many full-time barefoot runners out there. Second, as often pointed out by regular barefooters, barefoot running is a great self-limiter. It is hard to do too much too soon as a new barefoot runner because your plantar skin will let you know very quickly that it has had enough. And if you do go too far and damage your soles, it’s likely that you will need to allow things to heal up before you try again. As such, a very gradual buildup is almost a requirement for true barefoot running.
On the other hand, barefoot-style shoes prevent the friction that can damage the plantar surfaces. Thus, it is easier to do too much too soon because the skin does not act as a limiter, and if you don’t allow time for musculoskeletal adaptation to occur, a more serious injury than a blister is quite possible. This is why an extremely gradual adaption is so critical during a minimalist transition – you need to maintain immense self-discipline to avoid doing too much too soon.
Assuming that all of the 109 individuals followed in this study were running truly barefoot, the results suggest that transition injuries for barefoot runners are in fact fairly uncommon (only 17% of the 109 runners reported one, and only half of those actually had to see a medical professional for their problem). The dreaded metatarsal stress fracture that we hear so much about – only a single case formally diagnosed among the 109 runners. Plantar fasciitis? Only 2 individuals. Not a single diagnosed case of Achilles tendinopathy. Only 4 instances of self-reported calf or Achilles pain. The most common injury reported was, as might be expected, blisters.
It should be emphasized that this study is based on survey data, and we know little about the sample or the exact methodology. I am a bit suspicious by the low incidence of self-reported calf pain, as well as the rarity of blistering, even if it was the most common injury. It is possible that if the study subjects were die-hard barefooters, they might be under-reporting injury incidence. But, given the dire reports of injury risk we sometimes hear from the medical community (almost all anecdotal by the way), one wonders what the truth is. It will be very interesting to read the full study if/when it comes out.
So, rather than go on, I though it might be more interesting to post a few questions relating to this study and barefoot running injury risk and see what you think (wild speculation is encouraged!):
1. Given the results of this study, do you think injury reports coming from the medical community about barefoot running transition injuries might be exaggerated?
2. Do you suspect most injuries (e.g., metatarsal stress fractures) reported by the medical community are happening to barefoot runners, or is the moniker “barefoot runner” being used too loosely to include runners in “barefoot-style” shoes like the Vibram Fivefingers.
3. Do you suspect that injuries are less likely in a true barefoot transition than in a transition to barefoot-style shoes?
4. Do you think that injuries might be under-reported in a study like this (e.g., does the low incidence of blisters or calf pain concern you when it comes to believing these results?).
Any and all thoughts are welcome!