A COMPARISON OF 3 VIBRATORS IN STATIC POSTUROGRAPHY - THE EFFECT OF VIBRATION AMPLITUDE ON BODY SWAY

In static posturography, proprioception is often disturbed using vibra tors applied bilaterally to the calf muscles. The effect of vibrator a mplitude on body sway was compared in static posturography using bilat eral vibrators on the calf muscles of 30 healthy male military conscri pts at frequencies of 50 and 90 Hz. Postural stability was measured in terms of BSV (body sway velocity), and maximal displacements of the c entre of force (MAXY, MAXX) in the anterio-posterior and lateral direc tions. In comparing the effects of vibration to base stance without vi bration, BSV seemed to be the most sensitive parameter. A vibration of 50 and 90 Hz significantly influenced BSV values with the two most ec centric lends, an effect which could not be confirmed using any other parameter. This result could be obtained even with a small amplitude ( around 0.7 mm free/0.3 mm fixed) in our healthy subjects. The BSV effe cts may be even more pronounced in clinical work with patients with po stural disorders. Thus, when proprioceptive stimulation is used in pos turographic measurements, differences in the tested magnitude of the s timulation amplitude with a constant frequency will significantly affe ct postural stability, even In healthy subjects. Copyright (C) 1996 El sevier Science Ltd for IPEMB.