The Knee Bone, the Thigh Bone, and Adventures in Structuralism

After my last post, I got this comment:

Hi Richard, what do you think of the hip (especially abductor) strengthening exercises that are now being commonly prescribed for chondromalacia/PFPS? Seems like the dominant advice is shifting away from quad strengthening and towards hip strengthening. Have you tried it or done any research on it?

After reading this, that children’s song, “Dem Bones,” began running through my head:

The leg bone's connected to the knee bone,

The knee bone's connected to the thigh bone,

The thigh bone's connected to the hip bone …

Truly, we are all biological marvels. The way locomotion has evolved is astounding. I don’t profess to have much of an understanding of how, exactly, we walk and how this process can be both fluid and stable, but I know that it’s complex. Walking, running, jumping … our bodies have to recruit a bunch of different muscles and rely on certain supportive tissues to accomplish these activities.

Unsurprisingly, there appear to be some physical therapists who are fascinated by the biomechanical interplay that lies behind the movement of our lower limbs. They are fascinated by the connections, by how one thing seemingly remote from our knees (our butt muscles, e.g.) can influence a joint that is a couple of feet away.

A lot of them are structuralists (not my word, rather, the writings of Doug Kelsey first introduced me to the concept). Structuralism is the subject of this rather long post. Kelsey defines it as "a school of thought that believes the genesis of musculoskeletal complaints is from one or more biomechanical abnormalities."

And, for a structuralist trying to diagnose the source of patellar pain, abnormalities of interest include “a laterally tracking patella, weak medial quadriceps, tight hamstrings, tight iliotibial band, tight calf muscles, weak or tight hip rotator muscles and over pronation of the foot,” he informs us. (There’s our hip!)

One glaring problem with the structuralist story of knee pain, though, is that nobody has ideal biomechanics, yet most of us do just fine anyway. For example, I’m pretty sure I have a mild leg-length discrepancy. Yet it didn’t bother me for decades. Then, in my forties, I wound up with serious, chronic knee pain.

So was it because of my leg-length discrepancy? Or because I had been cycling recklessly up small mountains in Hong Kong, then piled on a long endurance hike on top of that one day, and that pushed my knees over the tipping point?

I think you’ve figured out where I stand on this. I’m not a fan of structuralism. There could be cases where it makes sense, but I would expect them to be a small minority. If your knee hurts – d’oh – why not start with where the pain is coming from? The knee? That’s more logical to my brain anyway.

I urge you to read that earlier post I linked to about structuralism, and especially take note of a study cited that looked at knee cap mistracking. Hell, that’s an instance of structuralism that even seems to make sense. A mistracking kneecap should cause issues, right?

But a study was done. And it found, basically, that whether a kneecap tracked improperly was no predictor of knee pain. You could have knee pain and a perfectly tracking kneecap, or no pain and a mistracking kneecap.

Physical therapists, in my experience, have been the biggest fans of structuralism. I had one who liked to have me do one-legged dips to check my alignment. I don’t think he ever figured out anything about my alignment. However, by putting so much force on what were bad knees at the time, he did manage to set me back in my healing.