Novel Vibrating Foot Orthoses for Improving Tactile Sensation in Type 2 Diabetes with Peripheral Neuropathy

Abstract

Improving tactile sensation by vibrating insoles was recommended to prevent foot ulcers in diabetic peripheral neuropathy (DPN). Lack of an insole design for diabetics was a challenge. Clinical trials on applying vibrating insoles with noise and stochastic resonance (SR) stimulating tactile were also required. In this study, vibrating foot orthoses (VFO) with a total contact design based on orthotics were proposed to provide proper insoles for diabetes. This study aimed to determine if VFO were beneficial at enhancing tactile in DPN. VFO were developed in combination with individual's custom-made foot orthoses and stimulation signals-integrating random 0-100 Hz square wave pulse signals with pseudorandom white noise by a SR approach. Sixty patients with mild-to-severe DPN were randomized to conduct crossover experiments: using and without VFO for 60 minutes stimulation at 90% of individuals' vibration perception threshold (VPT) level. VPT values when using VFO at the 1st and 5th metatarsophalangeal joints of the left foot decreased by 9.35% (P <.001); 9.04% (P <.001), and of the right foot decreased by 7.63% (P <.001); 7.24% (P <.001), respectively. Without VFO, there was no significant difference. Subgroups of mild and moderate DPN tended to benefit greatly from utilizing VFO. VFO can improve tactile in DPN. VFO may contribute to restoring/prolonging tactile and protective sensations, also decreasing peripheral nervous system deterioration. VFO might be useful for neurorehabilitation, and help prevent foot ulcers and disabilities.