Anecdotally a few patients have reported to me that changing from rear foot to forefoot running cured their knee problems.  However these same patients often end up seeing me for calf, shin or ankle problems.  Why?
 
I will start with a caveat that my findings are clinically, not research based.  That is I’m a treating athletes in a clinic instead of measuring them in a lab.  While there is a growing body of research on the matter findings appear to be mixed on the benefits of forefoot vs. rear foot running.  

Years from now as the body of knowledge has matured findings will be less murky, but I suspect that even then there won’t be clearcut answer.  Instead it’s more likely that we will find that the 2 running styles will predispose us to certain injuries and that we as the runner will need to decide which style suits us best.  Or maybe even a mix of forefoot vs. rear foot.

It makes sense anecdotally that the shorter forefoot stride will reduce impact and rotational / twisting forces on the knees.  Quite simply less momentum (read less impact) is developed with a shorter stride.

However by landing on the forefoot the runner is forcing the calf, Achilles and foot and ankle flexor group to work more than double time.  How so?  With a rear foot stride the Achilles and calf are fairly relaxed at impact (heel strike), but with a forefoot style the Achilles and calf take over the role of temporarily decelerating the leg. With a rear foot strike the much larger and powerful quad acts as a decelerator.  Whereas with a forefoot strike the calf, a much smaller muscle than the quad is being forced into the decelerator role when forefoot striking. 

Decelerating requires an eccentric or “lengthening contraction” of the muscle.  What an oxymoron?  Really it's just a controlled lengthening of the muscle.  This type of muscle contraction requires more force than a shortening or concentric contraction.  Think about the last time that you got really sore from a work out.  Chances are that it was activities that involve eccentric (lengthening) contractions like lunges, squats or push-ups.

While I'm not advocating one style of running over another (forefoot vs. rearfoot) it does makes sense to contemplate which style might make more sense for you.  If you have a history of Runners knee then consider a forefoot style whereas if you have problems below the knee then maybe it's worth trying rear foot.  Or consider a mix of the two.  Horses for courses.

Karl Bebendorf, DPT, OCS