Wednesday, June 9, 2010

Barefoot running, Chi Running, and the 3 Laws of the Kinetic Chain

A good friend recently asked me what I thought about Chi Running.

I like it.

Chi Running is one of many approaches that teach runners to run softer and absorb more forces in their proximal muscles.  The idea is that by having a strong core, particularly in the buttocks, less forces will be absorbed in structures that are not designed to handle high loads, including the knees and back.

This is similar in many ways to barefoot running.  Not everyone can handle barefoot running, but for those that do like running barefoot, the reason it works is that it teaches you to run more softly.  When you run with a heavily cushioned shoe, you can hit the ground with a very forceful heel strike.  This is not possible when you run barefoot- it simply would hurt too much to slam your heel into the ground.

This is, in my opinion, the reason why all the new barefoot simulator shoes on the market (including MBTs and Skecher Shape-Ups) can be helpful- because they have a rocker bottom sole, if you try to have a forceful heel strike, you roll forward, which dissipates the force.

Back when I was a Sports & Spine fellow in Chicago, my colleague (the late, great Jim McLean) and I noticed that we could explain essentially every musculoskeletal condition through 3 very simple rules, which I now refer to as "3 Laws of the Kinetic Chain":
1. Forces have to go somewhere
2. Range of motion has to come from somewhere
3. If the body cannot absorb forces or obtain range in a way that is anatomically appropriate, it will do so in way that is pathological

A great example is running with bad form.  Every time your foot hits the ground when you are running, the ground pushes back against your body in what is called a ground reaction force.  This ground reaction force can be several times your body weight, and it doesn't just disappear into the ether- those forces have to go somewhere.

So where do you want those forces to go?  Ideally, you want those forces to go into the biggest, baddest muscle you got- that is the gluteus maximus (your butt).  Other good choices are the quadriceps (the front of the thigh) and gastrocnemius (the diamond shaped calf muscle).  The more you can train your body to absorb forces into these structures while you run, the less force will be transmitted into your spine, hips, or knees.

Barefoot running is a method where your body will naturally train itself to use these muscles, because if you try to run by slamming your heels into the ground, it hurts too much.  This works ok if you can adjust your stride appropriately, but many people find this too painful to tolerate.

Some commercial products, most notably the Vibram 5-Finger shoes, have been developed that help protect the feet while you are barefoot running.

Chi Running is an approach that helps teach you to engage your core while running, which is the same general concept.  As a general approach, I think it is fine.  If I was seeing a patient in my Sports & Spine clinic, I would try and see if I can be more specific as to exactly which muscles the patient should engage, but as a first iteration, Chi Running is a very reasonable approach.

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