In this article, I’m going to be answering a common question about why we sometimes see a runner’s leg flick out to the side when running.
Thanks to Lucy for emailing with her question!
If this is something you’ve noticed in your own running gait, then please do read on…
Fixing the Leg Flick
Hi Lucy, thanks for the question. You’re certainly not the only runner with a noticeable ‘flick’ on one leg or both – it’s a common trait I see in athletes of all types.
Jeptoo is an excellent example of a runner who performs at the highest level despite what could be viewed as various biomechanical flaws in her running gait.
As the heel comes up behind and under the body when running, I’d like the foot to come through inline with the leg, when observed from behind.
Some runners, however, flick the foot outwards (as you describe), some flick the foot inwards towards the midline of the body.
Clearly, neither of these two flicking actions are what we want to see in a runner’s ideal form. Such a flick can be indicative of a number of different underlying flaws – often around the hips.
The following comments should be taken with the major caveat that I haven’t seen you run! Thus I’m talking in general terms based on what your question tells me…
Your question involves two key phrases which I feel are probably linked:
…but on the right leg when my heel comes up behind me it flicks to the right hand side.
My knees always seem to collapse inwards too…
Both the ‘flick out’ when the limb is swinging, and the ‘collapse inwards’ when the limb is in contact with the ground potentially point to the same dysfunctional factor at the hip: poor control of internal rotation and adduction.
I suggest you’d most likely benefit from targeted strengthening and control exercises working the external rotators and abductors of the hip, particularly Glute Medius.
Here’s a link to receive a useful downloadable resource to help you with your running form:
As I said, there are a number of other possible causes – but I’d need to see you face-to-face to look at your running to be able to comment further!