The complete frequency spectrum of physiological tremor can be recreated by broadband mechanical or electrical drive.

Two frequency peaks of variable preponderance have been reported for human physiological finger tremor. The high-frequency peak (20-25 Hz, seen only in postural tremor) is generally attributed to mechanical resonance, whereas the lower frequency peak (8-12 Hz, seen in both postural and kinetic tremor) is usually attributed to synchronous central or reflexive neural drive. In this study, we determine whether mechanical resonance could generate both peaks.

The ability to voluntarily control sway reflects the difficulty of the standing task.

Standing sway can be reduced simply by conscious effort but the extent to which this ability changes with stance conditions is unknown. Here, the influence of stance width and vision upon the ability to voluntarily reduce sway was investigated. 14 subjects were asked to stand either relaxed or still.

The effect of voluntary sway control on the early and late components of the vestibular-evoked postural response.

Electrical stimulation of the human vestibular nerve evokes a postural response which, unlike visually evoked sway, is unaffected by stimulus predictability. However, responses can be modified by changes in the level of background sway. Here, the effect of voluntary changes in sway magnitude upon the response to vestibular stimulation is investigated.