Immediate effects of footwear with vibration applied to the swing phase of the gait cycle on dynamic balance in patients with diabetic peripheral neuropathy

Abstract

Sensory and sub-sensory foot vibration have beneficial effects on the static and dynamic balance of patients with diabetic peripheral neuropathy (DPN). Previous foot vibration during walking was applied at sub-sensory threshold in both stance and swing phases of the gait cycle in DPN. This study aimed to investigate the effects of footwear with vibration above the sensory threshold applied to the swing phase of the gait cycle on the dynamic balance of DPN. Fifteen patients with DPN and 10 matched healthy control participants were enrolled in this study. Dynamic balance assessment was investigated by the sit to stand and turn tests while electromyography activity (root mean square, RMS) of the vastus lateralis (VL), tibialis anterior (TA), and peroneus longus (PL) muscles were recorded at baseline, after 10 min of wearing the vibratory sandal without vibration, and after 10 min of wearing the sandal with vibration. Repeated measure analysis of variance was conducted for data analysis. Wearing the vibratory sandal slightly increased the speed of weight transfer in both groups and COP sway in DPN (P > 0.05), and close to significant decrease of turn sway (P = 0.07) in both groups. There were significant differences of the PL RMS in turn test (P = 0.03) in DPN and peak RMS of the PL after 10 min of wearing the sandal with vibration in both groups (P < 0.05). The results of the present study demonstrated that PL activity was significantly influenced by the vibratory sandal as its tendon passing across the sole and in direct contact with the source of the vibration.