The effects of wearing textured versus smooth shoe insoles for 4-weeks in people with diabetic peripheral neuropathy: a randomised controlled trial

Purpose: To determine whether short-term wear of textured insoles alters balance, gait, foot sensation, physical activity, or patient-reported outcomes, in people with diabetic neuropathy. Materials and Methods: 53 adults with diabetic neuropathy were randomised to wear textured or smooth insoles for 4-weeks. At baseline and post-intervention, balance (foam/firm surface; eyes open/closed) and walking were assessed whilst barefoot, wearing shoes only, and two insoles (textured/smooth). The primary outcome was center of pressure (CoP) total sway velocity. Secondary outcomes included other CoP measures, spatiotemporal gait measures, foot sensation, physical activity, and patient-reported outcomes (foot health, falls efficacy). Results: Wearing textured insoles led to improvements in CoP measures when standing on foam with eyes open, relative to smooth insoles (p ≤ 0.04). The intervention group demonstrated a 5% reduction in total sway velocity, indicative of greater balance. The intervention group also showed a 9-point improvement in self-perceived vigour (p = 0.03). Adjustments for multiple comparisons were not applied. Conclusions: This study provides weak statistical evidence in favour of textured insoles. Wearing textured insoles may alter measures of balance, suggestive of greater stability, in people with diabetic neuropathy. Plantar stimulation, through textured insoles, may have the capacity to modulate the perception of foot pain, leading to improved well-being.IMPLICATIONS FOR REHABILITATION Short-term wear of textured insoles can lead to improvements in centre of pressure sway measures when standing on a compliant supporting surface. Wearing textured insoles may have the capacity to help relieve foot pain leading to enhanced self-perceived vitality in people with diabetic peripheral neuropathy.