Here’s a different study from the kind I normally cite:
Researchers in Sweden followed 75 junior elite basketball players, ages 14 to 20, over the course of a year. At the outset, they measured each player’s range when flexing his or her foot toward the shin.
The less flexible subjects had as much as a 30 percent risk of developing “patellar tendinopathy” (also known as “jumper’s knee”), compared with a 2 percent risk among the players who were more flexible. A dramatic difference, surely.
So what accounts for this? Could the study itself be flawed? Is it significant that the subjects don’t represent the broad population, but rather a taller-than-average subgroup of still-growing teenagers who were subjecting their knees to harsh physical demands?
Maybe. But what if -- at least for this population, and this condition -- the structuralist analysis makes the most sense. And, moreover, what if they should stretch (something I generally don’t believe is worthwhile)?
Now here’s the crazy thing about me: At any time, I’m willing to concede that all of what I believe may not be true (or, more likely, some of it may not be true). The epigraph to my book, remember:
The greatest obstacle to discovery is not ignorance -- it is the illusion of knowledge.
So it behooves curious, truth-seeking creatures to embrace flexibility of thinking, instead of stubborn certainty. Anyone who reads this blog a lot probably thinks of me as “that guy who hates structuralism.” Which isn’t quite true.
I dislike structuralism as the grand omni-explanation for nagging knee pain. It basically had nothing to do with my knee pain or how I fixed it. And, after doing a lot of research on the matter, I’m pretty sure it has nothing to do with a lot of other cases of chronic knee pain.
Still, show me a man with one leg six inches shorter than the other, who decides to take up running regularly, and I’ll show you a man who’s on his way to developing knee (and other) problems. At the extremes, structure certainly does matter.
Then you have the rest of us.
There is an enormous amount of variability among human beings. Obviously, we easily perceive the difference between the physique of person A vs. person B. But the concept of variability also applies to within the same individual as well, with regard to symmetry.
A famous example relates to eyes: We all typically have one eye bigger than the other. But this touch of asymmetry is surely true to some degree of our arms, legs and other bilateral structures as well. And some of us have another kind of variability: stronger quads than normal vis-a-vis calf muscles, or weaker gluteus vs. hip muscles -- or whatever.
Extreme deviations from the norm will naturally cause problems (e.g., the leg that is six inches longer than the other). Minor differences (such as a leg only 1 cm longer than the other) have been shown usually not to matter. Could, however, a certain amount of deviation from the norm, for certain anatomical structures, predispose a person to injuries/problems, at least somewhat?
Hmm. It sure seems likely. It passes the common sense “smell” test, if you will.
Given that, imagine two people, Jack and Tom. Jack can train by running 50 miles a week, no problem. But say that Tom -- because of a small difference in leg lengths, a slightly abnormal curvature of his spine, thicker bones, and a few other factors -- can run only 35. But he gets inspired by his friend Jack and starts training like him, running 50 miles weekly, and winds up with painful knees.
Now comes the interesting part. I’ve created a scenario where structure does matter (some). But what’s the most sensible way to treat poor Tom?
(1) Painstakingly go through and try to identify all the structural influences that may have predisposed him to the injury, correct them when possible (obviously you can’t change the thickness of his bones), then cross your fingers that you identified all the important factors and hope he gets better?
(2) Get Tom to work within an “envelope of function” so he doesn’t overstress his joints, and try to slowly expand that envelope over time, so he is comfortably running whatever number of miles a week his particular body can handle?
To me, #2 seems generally like a much smarter, more practical approach -- even if you believe that biomechanical (or structural) factors contributed in some way to his injury.