Busting myth busting. Static stretching and injury risk in runners.

Below you will see a picture from a 2007 handout I would give for talks about running injuries and stretching.  I had been anti-stretching for at least a decade.  At least, I was anti-people telling others they needed to stretch to prevent injuries. I’ve also written about it here, here and here.  It never made sense to me (it still doesn’t) so I enjoyed saying that the research at the time didn’t support stretching as an injury prevention method (again, it still doesn’t in runners)

From a 2005-2008 Injury Management Handout

But, where I was wrong was calling it a myth.  And many will still call it a myth today and we are still wrong.  

As Todd Hargrove (bettermovement.org) says it’s better to say it’s merely overrated.  

We can’t say its myth because the utility of whether stretching (either before a run or as part of fitness regime) hasn’t really been tested that well. What many of us (me included) have done was taken research in other sporting activities and applied those results to running (see this Lauersen 2018 paper).  Or what we have done is ignored some of the research that actually supported stretching as an injury prevention means. For example, a number of researchers for over a decade argued that stretching seems to reduce injury risk in activities where muscle strains are common (e.g sprinting and cutting).  This is explored in this paper here and supported in this paper as well.  If you just read the Lauersen 2018 paper you would think that stretching has no role in injury prevention. But here you have a group of researchers saying if you separate the type of injuries and the sport you will actually see a reduction in injuries. The papers can be seen in the table below.

But lets focus on endurance running

What I failed to do so long ago and for many years was to actually look at the quality of the evidence that specifically investigated the utility of pre-activity stretching and running injuries.  In the systematic reviews, primarily Leung 2011 and Baxter 2016 we see about 6 papers cited.  Let me highlight some of the massive limitations in those papers.

1. Pope et al 1998

• huge population of military recruits (not your typical distance runner)

• Performed 2 sets of gastroc and soleus calf stretches

• Held for 20 seconds.  Does 20 seconds seem like a lot?

• Both groups (control and intervention) stretched other lower limb and trunk body parts!
  
  
  Does this seem sufficient to say that stretching doesn’t prevent injuries? You have an extremely under dosed intervention and both groups actually stretched.

2. Pope et al 2000

• A big military population again.  

• Intervention group did 6 different muscle stretches but performed just one set of 20 seconds.

So, what do you think?  Is that a good dosage to make any conclusions?

3. Andrish 1974 - no comments, can’t find it.  No abstract

4. Liu 2008 - its in Chinese, no abstract, can’t find it and can’t read it

5. Hartig 1999

• they found a decrease in injuries. Go figure

6. Van Mechelen 1993

• static stretching was part of a warmup and cool down intervention

• They stretched the entire lower limb for 3 sets of 10s 

• They had a 46.6% compliance rate.
  
  Again, underdosed and a pretty poor compliance rate.  But, what I find most interesting is that many who might denigrate stretching in this study will then advocate dynamic stretching,  a warm up and cool down.  Yet, we see that those components were also “tested” and found wanting.  So, how about some consistency?

Consistency is the final theme here. 

Are we really being consistent in our criticism?  We seem to be holding stretching to a special standard for injury prevention.  Yes, there is very little and poor research suggesting that stretching can decrease injury risk in runners but there is also very poor or non existent research suggesting that our favourite injury mitigation strategies prevent running injuries.   All these things:

• acute to chronic work load ratio

• strength training

• “training error” avoidance

• Warmups and cool downs

…LACK EVIDENCE. 

…and all of those things I then recommended in my injury prevention guide from 2007 and still recommend them today.

From 2007 - nothing has really changed, eh?

… but everything above lacks good evidence. Just like stretching lacks evidence.  But we don’t go out and say they are Myths.  When a study pops up that fails to support our own biases we just say injury is complicated or we dissect the hell out of that study to say its shitty and therefore irrelevant - but I don’t we do this enough when a study conforms to our bias.  Take this paper on strength training and running related injuries.  This program was not effective in reducing injuries.  This study is probably superior to the vast majority of the stretching related studies but I’m guessing you won’t see people calling strength training for injury prevention a myth. You’ll hear that it is currently unsupported and lacks research (true) but we still advocate it.

PRACTIAL IMPLICATIONS

None.  Sorry, you got this far and I throw that out.  Nothing has changed for me in 20 years but my stridency. I still don’t tell people to stretch to prevent injuries.  That is an unsupported claim. I personally don’t believe it’s necessary to stretch as a runner. But, at the same time I acknowledge that I truly don’t know if it’s ineffective or effective.  No one does.  I would rather have people spend their time strength training, napping, hanging out with friends.  All things that may or may not prevent injuries but definitely have good secondary benefits. I still make the same recommendations for injury prevention but I try to be more cautious and consistent in my criticism and self reflection.