Vibrating insoles have interested researchers keen to investigate the benefits of biofeedback to aid people with balance has led to several studies. Boston researchers reported vibrating insoles could improve balance in patients with neuropathy found in people with strokes or diabetes. The vibration was adjusted to a sub-sensory level which appeared to sensitise neurons, making them more sensitive to stimuli that are present during standing. Previous studies had shown that sub-sensory mechanical noise delivered to the feet via the insoles could help people maintain better balance. Further research tested the effects of the vibrating insoles on sway parameters. The insole contained three vibratory devices embedded in elastic insoles (one below the heel and two below the forefoot areas). Each vibratory device operated independently and had a pressure switch that activated the underlying vibratory actuator. The vibratory device delivered a 70-Hz suprathreshold vibration pulse upon touch by the heel or forefoot, and the vibration pulse was deactivated upon respective push-offs. The sway patterns were significantly reduced and balance control improved with noise input. More recent research was undertaken on people with mild Parkinson’s disease. The gait pattern (walking) is affected by impaired in proprioceptive processing in the striatum so the pilot study was set up to assess the effects of enhanced proprioceptive feedback using step-synchronized vibration stimulation of the soles. The researchers reported augmented sensory feedback improved parkinsonian gait steadiness in the short-term setting. Further research was undertaken to develop more sensitive insoles. A C2 electromechanical tactor, a piezo actuator or the VBW32 skin transducer was activated by a custom-made noise generator, built in a cork insole and this was then amplified. Researchers concluded this design of vibrating insole may prove useful for further research into wearable technology for medical purposes.
Hijmans JM, Geertzen JH, Schokker B, Postema K. 2007 Development of vibrating insoles Int J Rehabil Res. 2007 Dec;30(4):343-345.