Is Hip Weakness Just Another Structuralist Bugbear?

A longtime reader who uses the moniker “Knee Pain” first got me thinking about weak hips and knee pain. Physical therapists were blaming weak hips for her pain. To me, that reasoning smelled a bit funny, right away.

My skepticism about “structuralism” immediately kicked in. In brief, my thinking about the structuralist tendency to blame imbalances and crookedness for knee pain goes like this:

1. At the extremes, structure definitely matters. If your right leg is two inches shorter than your left, you will have problems running a marathon for sure.

2. The majority of people, by definition, aren’t at the extremes, so structuralist explanations aren’t significant, or aren’t very significant, for most of us.

3. Structuralist reasoning doesn’t correctly explain the majority of knee pain problems.

Anyway, “Knee Pain” inspired me to write a couple of loooong posts more than a year ago that I think are among my best, which are here and here.

A big point in the first one: weak hips are probably not a cause of knee pain, but a result of it. Just because 30 knee pain patients happen to have weak hips does not allow you to conclude, “Ah hah, their weak hips caused their knee troubles!” In my corner of the world (financial markets), people like to quote a saying from the realm of statistics: “Correlation does not imply causation.” And pity the investing fool who doesn’t understand that elemental truth.

Anyhow, that’s a bit of a long windup to the introduction of a sort of meta-meta study done recently that supports what I suspected. It consisted of a review of 24 papers that looked at the relationship between hip strength and knee pain.

Michael Skovdal Rathleff, Ph.D., from the Department of Health Science and Technology at Aalborg University in Denmark, and his colleagues found “moderate-to-strong evidence from prospective studies indicates no association between isometric hip strength and risk of developing PFP [patellofemoral pain].”

As for why so many people with bad knees have weak hips ... well, that too is pretty much what I figured as well, according to Rathleff:

Hip weakness may not be the cause of knee pain — in fact, it is more likely to be a result.

Now, to be clear: Rathleff, who is quoted at some length in this article, isn’t saying hip strength doesn’t matter at all. In fact, he speculates that better hip strength, say, may allow a runner to withstand more loading on his or her knee joint before developing pain. This, to me, is the part of the structuralist perspective that does make some sense. Whatever you’re doing (running, walking, high jumping, etc.), a weakness in a muscle or tendon or other structure that is involved in that activity can affect your performance. Seems logical enough.

But it’s a long way from accepting that proposition to blaming those weak hips for your knee pain. It may make more sense to fault your knee pain for your weak hips instead.

Six Things I Like About Doug Kelsey’s New Book

I first mentioned Doug Kelsey’s latest book, The 90 Day Knee Arthritis Remedy, here. Kelsey, as anyone who read Saving My Knees knows, is the person that I credit the most with helping me figure out how to fix my knee pain -- and giving me the hope that I could be successful.

I planned to write a book review but -- yawn -- those are so 20th century, right? :) Plus, I can’t pretend impartiality here; I clearly owe him a large debt.

So instead, I give you this list of what I liked most about the book.

(1) The writing includes many examples. I like this style for a few reasons:

It makes for smoother reading.

It helps reinforce a sense of authority -- he can cite so many relevant examples because he’s seen so many patients.

It’s effective when showing how conventional wisdom for treating bad knees falls short, as with “Sue,” whose condition doesn’t improve when Kelsey, early in his career, tries applying the standard muscle-strengthening approach to fix her pain.

(2) He attacks foolish myths and exalts logical truths. For example, he talks about how, many years ago, he was perplexed by the idea that cartilage is inert and just wears out and nothing can be done -- end of story. He realizes something: This makes no sense. And it makes no sense, understandably, because it’s simply not true.

(3) You want exercises? You got exercises.

The book has plenty, with photos and video links too. Kelsey even includes multiple exercises to choose from when you have a highly sensitive and easily overwhelmed knee joint.

(4) The writing is smartly footnoted.

So Kelsey’s not just saying, “Here’s what I think” but “Here’s what I think and here’s some hard evidence why I think that.”

(5) There’s a little something for everyone.

There are abundant exercises if you’re just interested in therapeutic movement. There’s an analysis of dietary supplements if that’s what you want to know about. There’s Kelsey’s easy-to-digest explanation of the biomechanics of the knee joint.

(6) Plus, something I really like at the end: Kelsey concludes by taking a long look at “stumbling blocks.” Why, after trying so hard, have you failed to get better? This is the section that emphasizes the importance of getting your head right. How do you deal with doubt, impatience, failure to focus, worry? For some people, this part will be even more important than the description of all the exercises.

Last thing: I saw that “TriAgain,” who’s made some great, interesting contributions to this blog, made some remarks about what he saw as flaws in the book. I just wanted to say that, to be fair, Kelsey’s not a professional writer and he most probably didn’t have a professional editor helping to shape his prose. I happen to like Kelsey’s style, but that’s just me.

Also, try not to be too hard on him if he doesn’t respond to questions (or suggests you may need a “consultation,” probably at some cost). :) I can tell you, as someone who wrote a what-to-do-about-bad-knees book, that even though I lack the expertise to advise anyone, readers have approached me about essentially becoming their coach and sounding board. I always try to decline with tact and modesty, because really, I’m not qualified. So I imagine someone like Kelsey -- who clearly is very qualified -- gets scores of questions and requests. It would be overwhelming, I’m sure, for him to try to engage with everyone who wants to.

Still, I’m sure Doug Kelsey is as open to comments as I am, so anyone wishing to express an opinion on The 90 Day Knee Arthritis Remedy, whether good or bad, feel free to leave your thoughts below.

More Evidence That Running Doesn’t Destroy Your Knees

What group would you expect to suffer the worst repercussions from the relentless pound-pound-pound act of running?

What about marathoners -- and not only marathoners, but first-timers?

Surely, they must be asking for trouble, right?

Apparently not.

A study of five men and five women (yes, small sample size) showed that:

High-impact forces during long-distance running are well tolerated even in marathon beginners and do not lead to clinically relevant cartilage loss.

The researchers from Germany’s Freiburg University Hospital measured cartilage volume and thickness, using the very precise 3-D quantitative MRI, before the runner’s training began and immediately after the marathon. The small changes that were detected were not judged to be meaningful.

Incidentally, the subjects averaged 40 years of age, with a mean BMI of 25.9.

To be sure: running a marathon, especially if you’ve never done one before, can be disastrous for your knees. But the good news appears to be, with some sensible training, it doesn’t have to be. Running isn’t bad for your knees per se. Running dumb is what’s bad.