Transversus Abdominis Paradox

February 8, 2002

Here is a summary of some very interesting information that was sent to me

from top international researchers in the field of TVA activity and spinal

stability. For obvious reasons, no names are being mentioned at this stage

because their work is due to be published soon in a peer-reviewed journal.

Their information, together with Gray's recent feedback from that Spinal

Congress in Montreal decisively deposes many of the current guruesque beliefs

about TVA action and activation.

It will be interesting to see how those promulgating all those beliefs will

now respond. Will they openly admit their errors, will they subtly remove

the incorrect material from their web articles, course material and lectures

or will they declare that they were really saying " much the same thing, but

in different words " , which led to everyone misunderstanding what they

actually stated? Let's wait and see!

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TRANSVERSUS ABDOMINIS AND SPINAL STABILITY

TVA as activated through the abdominal " sucking-in " technique may not improve

spinal stability, as has been hypothesized, because reducing the moment arm

of the abdominal wall reduces the potential energy of the spinal column.

Furthermore, unstable behaviour occurs in the two shear directions and the 3

rotational axes, something which the TVA muscle is not really equipped to do.

However, if one executes an abdominal bracing action which activates the TVA

together with the obliques, this can significantly enhance stability in all 6

degrees of freedom for the lumbar joints. In fact, in terms of maintaining

spinal stability through a wide variety of tasks, the most important muscles

to ensure adequate stability CONTINUALLY CHANGE and no single muscle may be

singled out in that regard.

What does this imply? --- Train motion/motor patterns that involve all

muscles rather than emphasizing only one. This having been stated, it is

relevant to note that the Australian researchers in this field have shown

that they can correct delayed onset times of TVA activation with hollowing

training - this has merit for muscle re-education in clinical settings, which

is what they have always said - it is apparent that various others have

misinterpreted this to mean that this is the appropriate technique to build

spine stability in general.

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Dr Mel C Siff

Denver, USA

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