In my previous blog I talked about the simplest and most effective way for walkers to reduce impact to their knees and hips. So, in all fairness to you runners, this post is for you.

Since runners, as a rule, are a bit more injury-prone than walkers, the simplest way to avoid knee pain or knee injury is not as simple as it is with walking. I’ve read that running can increase your body weight upon impact by 6-10 times depending on whether you’re running on flat ground or running downhill. That’s an incredible amount of weight for your knees and hips to bear with every foot strike. So, it behooves us all to do everything we can to lower that multiple. If I weight 145 lbs. that means I’m putting 870 lbs. of pressure on my knees every time my foot hits the ground.

There are two reasons for this increase in impact to your knees. Part of that increase in weight comes from the fact that you’re leaving the ground between strides and as you return to earth, your body is accelerated by the pull of gravity. The other part of that weight increase happens because of the braking effect created if your foot happens to land in front of your center of mass. For most runners I’d have to say that is the biggest culprit of increasing impact.

So what’s the simplest solution?

Don’t step in front of your hips when you run. You heard me right… and you’re also correct if you’re thinking, “That’s easier said than done.” It’s not really that difficult to do, but it does take some patience and practice. It all comes down to learning how to run with a midfoot strike because it’s the best way to prevent your foot from landing out in front of your body. You can further reduce the amount of impact to your knees by landing with your foot even slightly behind your center of mass. This will minimize any chance of braking as your feet hit the ground.

If you’ve read the ChiRunning book you already know about landing with a midfoot strike and how that’s accomplished. If you haven’t read the book, I highly suggest you check it out. Another part of this equation is keeping your hips loose and your pelvis rotating. This will keep you running level across the ground and prevent the impact that comes from excessive bouncing.

If you can change where your foot lands and minimize your bounce you can seriously reduce the impact to your knees. I was recently tested at the gait lab at the University of Virginia and found that my vertical GRF (ground reaction force) was only 2.4 times my body weight. That’s a far cry from 6-10 times mentioned earlier!

My long range goal is, of course, to get that number down to zero… so I can run on water.

Happy trails,
Danny

Because I’m a lifelong advocate of fitness walking and injury-free walking, I’m always trying to come up with the simplest way to get walkers to move along the ground in a way that produces the least amount of impact to the feet, knees, hips and lower back. The answer to this dilemma is different depending on whether you’re doing ChiWalking or ChiRunning. I’ll begin with you ChiWalkers.

When I watch people walk I’d conservatively estimate that over 90% of all walkers lock their leading knee as their heel touches the ground in front of them. The problem with this (and most people don’t know this) is that when your heel strikes the ground ahead of your center of mass, it creates a braking effect on your forward motion. So you’re essentially pushing yourself forward with your rear leg while you’re simultaneously stopping yourself with your leading leg. We call it “driving with the brakes on” and it’s not only an inefficient way to move down the road, but it can create long-term impact damage to your feet, knees, hips and lower back.

According to the Joint Implant and Surgery Foundation there are over 200,000 hip replacements performed in the U.S. every year! I was totally shocked at this number. Here’s a small section of an article on hip replacements that I’ve borrowed from the JISF.org website:

“Hip joint load is a function of body weight, activity level, muscular force, and the distance from the body’s center of gravity to the center of the femoral head. Publications have stated that the hip joint force increases up to 2.5 times body weight with speed in level walking.”

Let’s see… two and a half times my body weight is 290 lbs. That means that when I walk at any kind of speed on a level surface there’s a force of 290 lbs. going to each of my hip joints with every step I take. Now, if I’m reaching forward with my stride and locking my knee, that means that that same amount of force is also going into my heels (plantar fasciitis & ankle problems), my knees (300,000 total knee replacements each year according to the NIH), my hips (you’ve seen the numbers), and lower back (The U.S. spends $50 billion each year on lower back pain). You’d think that here in the 21st century we could come up with a way to prevent some of this. Well, there is something remarkably simple that you can do the next time you find yourself walking somewhere. Are you ready for this earth-shattering piece of inside information? OK, here it is….

Don’t lock your knees when you take a step forward. That’s right. It’s pretty simple. Just make sure your knees are always bent as your foot comes down onto the ground ahead of you. Here’s how you’ll be helping your hip joint specifically. When you lock your knee the impact of your footstrike travels in a direct line from your heel to your hip because all of your bones are lined up in a straight line. On the other hand, if you bend your knees, that impact is dispersed through your feet, ankles, and knees before it reaches your hip…and the resulting impact to your hip becomes almost negligible.

Of course, if you’re used to walking with your knees locked, this means a change in what is probably a longstanding habit. Remembering to do it is the hardest part, but it is much easier to do if you can remember to always work on walking with your posture well-aligned with your shoulders and head slightly forward of where you are used to carrying them. It’s just a very slight forward tilt of your upper body whenever you’re walking.

Another way to accomplish the knee bend when you walk is to shorten your stride and quicken your cadence. You’ll sense that you’re taking smaller, quicker steps, but your legs will feel very different as will the impact on your hips and knees. It might feel a bit strange at first, but if you go back and read the statistics about knee and hip replacements and think of the alternatives…you might be more willing to watch your step.

For more information on injury-free walking and fitness walking please visit the ChiWalking website.