New Study on What Shoes do to Your Knees


The news media is picking up the results of a new study showing that running shoes are worse on your knees than running barefoot. The stories also mention that even high-heeled shoes are better (though, in all fairness, this is a bit of comparing apples to oranges).

The L.A. Times story is here. They had done a story back in October featuring Barefoot Ken Saxton of, so the writer of the new article wasn’t too surprised by the study results.

The Daily Telegraph also has a story. In this article is it made clear that the study showed that running in running shoes is worse than walking in high heels.

The lead author of the study, Dr. D. Casey Kerrigan, has been doing these sorts of studies for a long time. “Knee osteoarthritis and high-heeled shoes” and “Women’s shoes and knee osteoarthritis” are the two studies she was involved with that showed the effect of high heels on walking.

The new study, The Effect of Running Shoes on Lower Extremity Joint Torques”, shows that knee varus torques and knee flexion torques are about 40% higher in running shoes than barefoot, and hip internal (or medial) rotation torques are about 50% higher. It was published in the journal of The American Academy of Physical Medicine and Rehabilitation: PM&R, Volume 1, Issue 12, Pages 1058-1063 (December 2009).

The knee varus torque refers to the left/right forces on the knee as you run or walk. The knee flexion torque refers to the front back motion. These sorts of stresses on the knee bones and cartilage are implicated in osteoarthritis of the knee. The hip medial rotation refers to rotation of the thigh about the hip.

The study itself ends with a rather odd sentence:

The use of athletic footwear in running as a means to protect the foot from acute injury and the potentially debilitating effect of switching to barefoot running on foot health excludes such an alternative.

Huh? This statement appears to be without foundation, and just perpetuates the usual fears about going barefoot. I’m not even sure what they mean by “acute injury”, but I can guess that they mean something like stepping on glass. That is extremely rare, and even more rarely “acute”. In fact, most of the “acute” foot injuries are bloody blisters, caused by shoes, not going barefoot. It is also not clear what they are thinking about barefoot running having a “potentially debilitating effect” on “foot health”. What is telling, though, is that this statement does not have any citations associated with it (as they did with their other remarks that actually were based upon other studies).

Oh, and the recommendation of the study? Come up with new footwear designs. That is, after all, what Kerrigan’s company, JKM Technologies, does. I’m sure that didn’t affect the results of the study, but it does show a certain blindness towards a possibly more effective (and cheaper) solution: running barefoot.


3 Responses to “New Study on What Shoes do to Your Knees”

  1. Pete F Says:

    I am an avid barefooter and proponent to being healthy barefoot however, One thing concerns me about the recent increase in popularity with regards to running (or living for that matter) barefoot. Its very rare to find anyone who writes about the benefits of running barefoot to mention (other than “don’t stem on anything sharp”) that most shodies are not properly conditioned to engage in any serious barefoot activity. What I mean by this is that wearing shoes all day, every day, for ones entire life leaves your feet soft, tender, weak, and barely capable of functioning with any degree of capability just because you ask them to.
    You can believe that being barefoot is better for you so please DO give it a try, but please DO NOT go out and try to run a marathon or walk the Appalachian train barefoot without FIRST doing a bit of research. While sifting through the loads of information available – common sense should be your guiding light. If it seems to make sense to you, then it probably does. Also make sure you take it slow and allow yourself to get conditioned properly before attempting anything involving any degree of endurance.
    What Id really hate to see is thousands of people try to change over into barefootedness, do it wrong, get hurt, and give barefooting a bad name.
    Barefooting is a great way to live and get or stay fit but like everything else in life, anything worth doing usually takes time to perfect.

  2. Darren Says:

    Good points about taking it slow when taking those first steps away from a lifetime in shoes to experiencing the unfamiliar feedback of walking barefoot.

    I always tell first-time barefoot hikers that they will likely experience some soreness in the calves and possibly elsewhere in the first couple days after their initial barefoot hike. This is no cause for alarm; it’s no different that the soreness someone would experience after going to the gym and working upper body muscles for the first time in months or years.

    Bottom line: The more one exercises their feet, the stronger they get. The best way to exercise the feet is through exercising barefoot. If there weren’t so many companies trying to sell shoes for specific types of exercising, this would probably be an easier concept for most people to grasp.

  3. Adan Denne Says:

    i see some women who choose womens shoes that are brightly colored and very stylish ;”:

Comments are closed.

%d bloggers like this: