Apr 28, 2011

The tension in your body - Icosahedron

6 dowels + 12 tacks +
24 rubberbands = 1 icosahedron

I'm so excited to share my tensegrity model! With just six dowels, 24 rubberbands and 12 thumb tacks, I was able to assemble this icosahedron (20-sided shape of equilateral triangles) in about 5 minutes. No glue or nails are used to hold this sturdy structure together. The equal tension of the rubberbands around the ends of the dowels (held in place by the tacks) keeps it all together, even if I press down on it or stretch the individual components apart.

I built the model using instructions provided in the 2nd edition of Anatomy Trains: Myofascial Meridians for Manual and Movement Therapis, by Tom Myers (Myers, 2009). Throughout the manual, Myers employs photographs of Thomas Flemons's beautiful and complex biotensegrity models, available at www.intensiondesigns.com. This one is much, much simpler, but still lots of fun to play with, and useful as a tool to illustrate how our bodies work and relate to stress (that is, mechanical stresses).

Keeps its shape, even if you squish it!
Tensegrity is the words 'tension' and 'integrity' smooshed into one. The basic idea is that (structural) integrity is maintained through tension. The term tensegrity was coined by designer, engineer and futurist, R. Buckminster Fuller (of soccer ball-esque buckyball fame) and was used to describe the profound sculptures of Kenneth Snelson (Oregon-born, no less).

Other common instances of tensegrity are tents, spiderwebs and suspension bridges. But what's cool about this tensegrity model is its independence from external support - it holds itself together, despite external forces (like if I were to throw it as hard as I can against the ground), through its intrinsic balance of tension and compression forces. And it does so with the absolute minimum of materials. This means the structure is optimally efficient to handle stress, because it distributes stress equally across the whole system. Put another way, "tensegrity structures are mechanically stable not because of the strength of individual members but because of the way the entire structure distributes and balances mechanical forces." (Ingber, Donald E, "The Architecture of Life", Scientific American Magazine, Jan. 1998)

The cat inspects the 20-sided contraption
So as a massage therapist, what can I say about the relationship of the body to mechanics, architecture and the distribution of forces in an icosahedron? Put another way, if a client comes to me, describing pain in her left hip, why might I begin a series of treatments working on her feet, or perhaps her right hip, and not work directly on the area of pain?

Going back to the icosahedron model, if you push one of the dowels, or pinch a rubberband, you can can see the whole structure respond. If you continue tweaking it more and more, this increased strain is nonetheless distributed around the whole figure. Finally, when there is so much stress that it breaks, likely as not, the breaking point won't be where you were stressing it the most, but will be at the weakest point of the structure, perhaps far away from where you were tweaking it. The idea is, the same thing happens in the body. To relieve pain in the hip, we have to look at and treat the body as a integrated whole. If we do not find and relieve the imbalanced lines of tension around the hip, then dysfunction causing pain in the hip will not be resolved.

Thanks for reading!

All content authored by Kate Barkume, Licensed Massage Therapist, Portland, Oregon

No comments: