## Biotensegrity Book

The book entitled: **Biotensegrity: the structural basis of life** is now available for purchase from Handspring publishing and contains much information on the origins of tensegrity and the biotensegrity concept, the underlying principles and their implications for functional anatomy, biomechanics and clinical practice.

However, the preparation necessary for writing it included wading through a considerable amount of information before finally deciding what to include, and the mathematics was kept to an absolute minimum; but there was a glaring mistake.

There are only two equations in the whole book and I got the most important one wrong! I am not sure how it happened because everything was checked over and over again – but it was wrong. Nobody noticed, or at least they didn’t tell me until six months later, but there it was, staring me in the face… and maybe you as well.

The offending equation was contained in figure 4.4, which shows that a two-kilogram fish suspended from a three-metre long rod would require a balancing force that exceeds the strength of the lumbar erector spinae muscles if considered as a lever system.

Assuming that the distance from the centre of the lumbar vertebrae to the spinal musculature is about five centimetres (0.05 metres), the amount of force that would be necessary for these muscles to balance the fish (according to the standard lever model) would be 120 Kg; but the maximum strength of these muscles is only 35 Kg, which shows that the standard lever model is inadequate to explain the reality.

The later printings now show the revised illustration; and in case you are interested, the erroneous calculation was: (2 x 3)/0.05 = 600 Kg and the strength of the back muscles was incorrectly given as 400 Kg; outrageous!

Many apologies and hope you enjoy the rest of the book.