View Full Version : abdominal exercises and spinal unloading

02-06-2007, 12:13 AM
Dear Colleagues:

We performed an experiment that involved abdominal exercises (3 sets of
three 3 series of 20s with interval of 30s) and measured spinal length
immediately after. We measured spinal shrinkage using a precision
stadiometer (Rodacki et al., 2001, Boocock, 1996) that allows assessment
of small stature changes.

Interestingly we found stature increases, which indicate an acute spinal

Abdominal exercises are thought to produce compressive forces (McGill,
1998, Phys Ther 78 (7) p. 754-765) that reach high values (varying from ~
1700 to 3500 N). Thus, we are struggling to explain our stature growth
after exercising, which were very consistent between subjects. These gains
at the end of the exercises were greater than that observed during the
same period of time (4.5 min) in a resting posture (Fowler position),
which is a well known unloading posture used to relief LBP.

How can the intervertebral discs to increase height under compressive
forces? This is opposite to what we have found in the literature and seems
to be at least puzzling.

Any comments on possible underlying mechanisms will be welcome.


André Rodacki
Universidade Federal do Paraná
Cuririba – Paraná – Brazil
mail to: rodacki@ufpr.br