Running

Run, run, run as fast as you can…

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So this year's running plan is looking the goods. Eugene Marathon is on in May and then there is Newport in June. And then Hood to Coast in August.Training to date has gone well esepcially thanks to Club Sport, a gym we joined last month.

Last year went well with two marathons, the latter in Portland with what I think is the ultimate pair of shoes. I have been experimenting with minimal shows for some time but these Vibram Five Finger Speeds from the UK seem to do the trick. They are 4 – 5 ounces and held up great in the relentless rain of Portland Marathon last October. No blisters, nothing.

The shoe experimentation all started thanks to Dr Ray Maclanahan, a Portland podiatrist who got me back running just as we arrived in the US after a 5 year break.  I was happy to see in this post below from Runblogger that Ray is having a broad impact. The below are notes from a recent running injury prevention conference. It also lays out what we all really know in our hearts (!) – we were born to run. And the big bulky running shoes are the problem not the solution (Sorry Nike).

1. Running is good for humans – it has been shown to significantly reduce both mortality and disability risk.

2. Running doesn’t ruin our knees, in fact it might actually benefit knee cartilage over the long term (see this NY Times article for more)

3. Lots of runners get hurt – range is 20-80% depending on the study.

4. Most running injuries are overuse injuries that can be attributed to stubborn and obsessive runners doing too much too soon. In doing this, runners exceed their body’s stress threshold and something gives. The end result is an injury. I wrote a post largely devoted to the topic of overuse injuries in runners a few months ago.

5. Many running injuries are associated with some kind of change in a runner’s training. Could be a change in shoes, running surface (e.g., running on the treadmill all winter then resuming the same mileage on the roads when it warms up, mileage, volume of speedwork, etc).

6. From pre-1970 to today, running shoes have gotten progressively bigger and bulkier, with lots of added cushion, proprietary “technology”, and raised heels.

7. There is no scientific evidence supporting the efficacy of “big, bulky shoes” (Blaise’s phrase describing the modern running shoe) with extensive cushioning and a large heel lift for the prevention of running injuries. However, we also have no direct evidence that big, bulky shoes cause injuries, or that minimalist shoes or barefoot running are better at injury prevention.More studies are needed!!!

8. Most “technological features” in modern running shoes are likely nothing more than marketing gimmicks designed to appeal to customers and sell more shoes. Little objective and/or publicly available evidence is available to support the efficacy of proprietary technology in shoes.

9. Big, bulky shoes change how we run. They cause us to run in a very different way than we do when we run barefoot, which is how the human body evolved to run (see Lieberman et al., 2010, Kerrigan et al., 2009, and Squadrone and Gallozi, 2009 for some recent examples of how shoes change our gait). In general, barefoot running causes us to run with a shorter, quicker stride and a forefoot landing. Many additional examples of studies looking at barefoot vs. shod gait are available, and a number of them are cited in this post by Phil Shaw).

10. Higher vertical impact loading rates (how fast impact is applied to the body – think punching a wall with your bare fist vs. a boxing glove) have been linked to injuries like lower extremity stress fractures (see this review paper by Zadpoor and Nikooyan, 2011). Conversely, Nigg, 1997 reports results of what appears to be an unpublished graduate thesis suggesting that impact force and loading rate are not linked to injury, and that increased loading rate was actually associated with fewer injuries. However, this analysis looked at short term injuries and did not look at injuries by specific type. I am hesitant when trying to interpret results from research that has not been published in a peer-reviewed journal, and currently am trying to get ahold of the thesis. In contrast to Nigg’s findings, Davis et al. report results of a prospective study in a conference abstract showing that vertical impact peak and vertical loading rate are linked to a higher incidence of running injury. More studies are needed!!!

11. Forefoot striking has been shown to reduce vertical impact peak (many studies, Lieberman et al., 2010 is a recent example) and vertical impact loading rate (Oakley and Pratt, 1988; Williams et al., 2000) relative to heel striking. Data showing no difference between forefoot and rearfoot impact loading rate is out there (e.g., Laughton et al., 2003), but data are limited that involve people well acclimated to multiple landing types. Data on loading rates are sometimes difficult to interpret if runners are not acclimated to a barefoot running style – for example, De Wit et al., 2000 showed dramatically increased vertical loading rate in barefoot runners compared to shod runners, but their barefoot runners were heel striking. One would fully expect a barefoot heel strike to exhibit a higher loading rate since little cushion other than the heel fat pad is present to slow down force application. Lieberman et al., 2010 showed that habitually barefoot runners overwhelmingly land on the forefoot, which suggests caution when interpreting studies of barefoot heel strikers (who were probably unaccustomed to running barefoot).

12. Big, bulky shoes dramatically increase torques on the knee and hip joints compared to running barefoot (Kerrigan et al., 2009). In particular, running in shoes increases a knee varus torque, which forces the leg into a more bowlegged position and compresses the medial portion of the knee (a primary location for osteoarthritis). We don’t yet know the significance of this to injury risk, or how much additional torque is too much. However, if one can avoid torqueing joints by emulating barefoot running, this might not be a bad thing.

13. Simply increasing cadence (stride rate) may provide positive benefits in terms of joint loading. For example, Heiderscheit et al. 2011 showed that running with a faster cadence/higher stride rate (5-10% increase) reduced loading on the knee and hip, allowed for a more level carriage of the center of mass (less vertical oscillation),shortened stride length, and created less braking impulse. Read my post on the Heiderscheit paper here.

14. Studies that have assigned shoes to runners based on static measures of the foot (e.g., arch height, foot posture index) have shown little benefit when shoes are assigned either appropriately vs. inappropriately based on the static measure (Ryan et al., 2010; Knapik et al., 2009; Knapik et al., 2010a; Knapik et al., 2010b). These results show that either static measures are not a good way to assign shoes (so much for the wet footprint test!), or that pronation control is not a good basis on which to choose a shoe. For summaries of this work, read my post on thepronation control paradigm or a great article on the topic from Gretchen Reynolds of the NY Times.

15. Pronation control is not a good basis on which to choose a shoe, and should not be the foundation upon which such decisions are made (as is currently the situation). Read Nigg, 2001 for more. Benno Nigg also just published a book in which he tears apart the pronation control paradigm.

16. Our feet are screwed up. Ray McClanahan talked about how our shoes are too narrow, and narrow shoes disfigure the foot. If you look at your foot and notice the big and little toes pointing toward the middle of the foot, it likely means that your foot has molded to the shape of a shoe with a narrow, pointed toebox. The picture at left from Edward Munson’s book “The Soldier’s Foot and the Military Shoe” provides a very visual example of this. He believes that mis-alignment of the big toe compromises our stability and can lead to problems with the running gait. One simple way to see just how narrow your shoes are – take out an insole and stand on it (weight-bearing). Notice how much your foot spills over the sides of the insole. That is the portion of your foot that gets restricted by your shoe.

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