Another Lesson in Biomechanics, or, The Foot Bone is Not Connected to the Eye Bone

Thought I'd offer a little more insight into the inner-workings of our feet. We clubbies can't know too much, is my view, as the more you know, the better your understanding and communications will be with the docs you deal with.

Today, lets look at this whole idea of "range of motion." Simply put, this just means how many degrees of motion is available to a particular joint versus how many such a joint should have within a so-called normal range. For example - your elbow joint has a normal range of roughly 150 degrees. It would not be possible to have much more than that, as your biceps sort of get in the way. But injury can cause that amount to diminish, or someone with a very loose ligament structure might be able to hyper-extend their arms such that the amount might be greater. This is just to help it be understood that your range may be different than the "normal" range for any given joint.

This is especially true for post-club feet. And not only in our subtalar joints. The mid-tarsals, the calcaneal-cuboid, and the ankle joints will almost certainly display reduced and constricted ranges of motion. By constricted I mean that the joint might be capable of being stretched to a normal range, but in functional terms it is either too painful, or the arthritic changes make it increasingly stiffer, and thus have a lesser range available.

Now, remember - no joint operates in a vacuum - they are all working in a chain, as it were. Each joint has some level of influence on other joints, and not merely the ones on either side. The subtalar joint, as the most pertinent example, has an effect on nearly every joint proximal (further up the body) and also distally (toward the end of the foot, in this instance.) This is due to the function this particular joint plays for all phases of gait, or ambulation. Other joints, such as the calcaneal-cuboid, can influence the subtalar joint, both in its range of motion, and in its biomechanical alignments during each moment of that motion.

Here's an example: take a small box, like a box of tissues, and place it on a table. Take a small plastic cup, and place it on top of the tissue box, then place a small plate on top of the cup. Right now, everything is stable. You can shake the table, and the stack might jiggle or vibrate, but if you centered everything, the stack will probably remain upright.

Now, take a spoon, and insert the handle of the spoon beneath the tissue box, any side will do. The curvature of the spoon handle will cause the stack to tip a small amount. Now, shake the table again. The stack might remain intact, but the small plate will almost certainly shift, because you have altered the relationships between each object. Take another spoon, and insert it beneath the small cup, but on the opposite side as the first spoon beneath the tissue box. Again, shake the table. Now, you can see the instability of the stack has increased.

The place where two bones meet at a joint is called the articular space, or the articular surfaces. This is where one bone articulates - moves - against the other. The shape of each of those bone's articular surfaces is what determines certain aspects of range of motion, as well as direction and quality of motion. If, for example, there is a bone spur on or at the edge of an articular surface, it will alter the normal motion available to that joint. Likewise, alterations in tendon or ligament strength, placement, or tension (laxity, for example) will change the range and quality of motion.

Clubbies have, by definition, altered joint articulation, or patho-mechanics. Patho-mechanics is just a ten-dollar word for things not working normally. That is, they vary from "normal" biomechanic functioning. We have had our feet stretched, casted, surgerized, braced, twisted, tightly encased, and abused in myriad ways. All in service of "fixing" our feet. Unfortunately, there has never been a way to be certain, from one clubby to the next, if the articular surfaces were optimally aligned. Getting a foot to "plantigrade," that is, the sole of the foot on the ground, has been the primary measure us success with club foot treatments, and that can be accomplished without ever acquiring excellent, or even good, alignment. Add to this the action of stretching, casting, bracing, and encasing the small, growing foot. The relative strength of the tendons, ligaments, and muscles on opposing sides of the joints will nearly always be less than ideal, and sometimes downright wrong.

This is why those of us clubbies who did not have the best of all possible outcomes face an increased propensity for arthritis in the joints of our feet, not to mention ankle and knee problems. There is even cause to believe, (though no real evidence, as no studies into the question have ever occurred) that we face a higher-than-average probability for hip replacements down the line. Again, these are all a function of reduced and restricted ranges and quality of motion in some or all the joints of our feet.

I realize my posts are often depressing as all get out, and I apologize for that. But for too long, folks lie us have had to grope in the dark for answers and for better understanding of what we face, and why things just didn't work as well for us as for some other clubbies. So that is why I do this blog.

On a somewhat different note, I think I better understand why so few of you dear readers have wanted to tell your own stories. For me, its been the focus of a significant part of my work life, as well as my daily experience. Plus, I do a lot of writing, so I have few inner prohibitions about being open on this issue of being a clubby. But I suspect many of you have had what I also had - lots of negative input - teasing, maybe bullying, and the constant reminder of your feet making you "different" than your peers. So I'll try not to pester you anymore for your story. If you wish to share, it is certainly welcome, but if not, that's fine, as well. The last thing I want to be, to other clubbies, is a pressure from yet another direction.

So, Happy Thanksgiving. Enjoy the meal, and your friends and family. And thank your feet for carrying you this far, so far. It wasn't their fault, and it isn't yours. It's just what we were given, and we can't be blamed for that.

And as far as I've been able to determine, there is no such thing as an eye bone. There is, however, the occasional sharp stick in the eye, of which I have a wee bit of familiarity.