Anatomy Trains

We got to tour the biomechanical lab at the University of Ulm today. I am both fascinated (on an intellectual level) and repelled (on a human level) with such research. It seems to me that people are going to a lot of trouble to reaffirm Wolff’s elegant Law (en.wikipedia.org/wiki/Wolff’s_law), which my students have heard me paraphrase many times, to be carved in gold over the door if I ever build a school: The Body Responds to Demand. Wolff was talking about bone, and others (Davis, I think) have applied it to certain connective tissues, but Wolff got it first and got it right – so much of the Anatomy we now learn originated in Germany, building on the foundations set in Padua and Bologna by Vesalius and his compadres. See Spalteholtz and Hoepke, among others.

The current amour with tissue ‘remodeling’ in these labs is just elaborations on the mechanisms and limits of Wolff’s Law. It has been fascinating in terms of understanding the mechanism by which mechanical tension / compression in the extracellular matrix is conveyed to the nucleus to alter gene expression (again, follow Don Ingber, or read that latter part of the first chapter in the 2nd edition of Anatomy trains for my take on mechanobiology). The altered gene expression in turn allows the ECM and the body to respond within biological limits to the new load.

I was fascinated to learn how fast this happens: astronauts in space lose 200-300 mg of calcium per day from their bones, and there is up to 40%-60% loss of bone mass in a paraplegic’s paralyzed limb – apparently the limits are pretty wide. I can imagine that would mean that with the same old usual genes, we would be pretty much planet-shaped (round) after an extended period in space.

Now, I know a number of Americans are attempting to reach this shape via fast food, but not being in space (other than in their anti-‘socialist’ little heads. (if only you knew how crazy all the Tea-Baggers look from Europe, painting Hitler mustaches on Obama’s face for this tiny transitional step toward what every European knows: Hitler was very, very much worse (and truly fascist) than Obama, and socialism in health care is a very good and economical idea) Being big and round on the planet Earth is really hard on your knee ligaments and your heart, but in space, adopting a round shape would be a sound adaptation.

But it is those strained knee ligaments – in sports as well as obesity – that concern the bio-engineers here in this state of the art facility. Our loud Russian friend Leonid, a pig-tailed Sue Hitzman, Kinesis UK’s James Earls and his fiancée and Pilates teacher Ines and some others sat around a table (in ‘laboratory chic’) examining a cadaverous knee. It had been stripped of muscle, and the two bones set into cones of bright yellow plastic, which will be held by the machine.

The machine, a modern torture instrument in looks, can hold the joint complex very firmly, and then apply multiple repetitions of flexion-extension or tibial rotation while maintaining true knee movement ( which is anything but simple – sliding and gliding and ‘screwing home’ (that’s the actual term) in the last degrees of extension – all accounted for in this machine. But they can add extra torsion or valgus or varus into the equation and then measure what that does to specific ligaments or fascia.

You might be shaking your head in wonder or disgust (there was a big portrait of Isaac Newton on the wall – had they never heard of Einstein or Wiener?), but how the hell else are they going to figure out how to make good artificial ligaments or better surgical procedures?

Another machine pulls on tendons to test recovery from stress and what happens in tendinous injury. Really intriguing problem: how do you hold onto a tendon, which is really slippery, to raise the tension to 50,000 Newtons (5000 kilos, more or less)? The homely answer is sandpaper between two metal plates. In this little detail I suddenly felt heartfelt empathy for these researchers, however much I rebel into being a proponent of holism when I see their reductionist approach and the endless beeping machines.

They are of course sincere (and in this case well-funded), but the elegant and homely solution to this problem (as well as the whimsical sculptured chairs in the lobby) earned my slightly grudging respect. They are still studying the body in parts, and there is still more to learn from this path, even though my own path takes me down the road toward what can be learned for the synergetic interaction of whole systems. As I have said before, scientists have the luxury as well as the discipline to reduce each question to a narrow single variable.

On a daily basis, the working therapist must juggle a thousand variables which cannot be either put out of the way or ignored – of fear, of relationships, of predilections and stubborn beliefs, of the need to lift children and tend to parents – in our clients. So we live in a no man’s land between science and art and craft. A scientist in a lab can dismiss our ‘unscientific’ attitude all he or she wishes, but let him be faced with the range of human suffering and striving every day, and see how many of his neat delineations survive in the rough and tumble of real therapy, real life, and hands-on-the-body application.