First, a pilot study was conducted with untrained elderly ("Effects of stochastic resonance therapy on postural control in the elderly population" (KEK Bern: No.228/09, Clinical Trial Registry: NCT01045746). Following, a second pilot study was conducted with frail elderly (Application of Whole-body Vibration With Stochastic Resonance in Frail Elderly: The Effects on Postural Control Clinical Trial Registry:NCT01543243).