For the SOT'ers among us, this is an interesting study.
>
> Della Volpe R, Popa T, Ginanneschi F, Spidalieri R, Mazzocchio R,
> Rossi A
> Changes in coordination of postural control during dynamic stance
> in chronic low
> back pain patients. Gait Posture. 2005 Nov 24.
> Sezione di Neurofisiologia Clinica, Dipartimento di Scienze
> Neurologiche e
> del Comportamento, Universita' di Siena, Policlinico "Le Scotte",
> Viale Bracci,
> I-53100 Siena, Italy.
>
> The human postural system operates on the basis of integrated
> information
> from three independent sources: vestibular, visual and
> somatosensory. It is
> conceivable that a derangement of any of these systems will
> influence the overall
> output of the postural system. The peripheral proprioceptive system
> or the
> central processing of proprioceptive information may be altered in
> chronic low
> back pain (CLBP). We therefore investigated whether patients with
> CLBP exhibited
> an altered postural control during quiet standing. Dynamic
> posturography was
> performed by 12 CLBP patients and 12 age-matched controls.
> Subject's task was
> to stand quietly on a computer-controlled movable platform under
> six sensory
> conditions that altered the available visual and proprioceptive
> information.
> While the control of balance was comparable between the two groups
> across
> stabilized support surface conditions (1-3), CLBP patients
> oscillated much more than
> controls in the anterior-posterior (AP) direction in platform sway-
> referenced
> conditions (4-6). Control experiments ruled out that increased sway
> was due to
> pain interference. In CLBP patients, postural stability under
> challenging
> conditions is maintained by an increased sway in AP direction. This
> change in
> postural strategy may underlie a dysfunction of the peripheral
> proprioceptive
> system or the central integration of proprioceptive information.
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