Hongwu Wang, Raghuveer Chandrashekhar, Kyle W Ruffing, Roger B Fillingim
Targeted force-based manipulation via wearable FVT offers a highly feasible mechanism for pain relief and changes in gait biomechanics in DPN. By uncoupling neuropathic pain from functional ambulation, this intervention provides preliminary, hypothesis-generating evidence that supports the need for further investigation in fully powered trials.
BACKGROUND: Diabetic peripheral neuropathy (DPN) disrupts somatosensory feedback, causing chronic pain, altered gait mechanics, and elevated fall risk. While force-based manipulations are known to modulate nociception and proprioception, their biomechanical effects and clinical efficacy in DPN remain underexplored. This secondary analysis investigated the effects of a wearable, force-based focal vibration therapy (FVT) on pain relief, estimated fall risk category, and gait performance in adults with DPN.
METHODS: We analyzed data from our single-blinded, parallel-group pilot trial of 28 participants (Experimental Group [EG], n = 25; Sham Control Group [CG], n = 3). Participants completed a 4-week home-based intervention. Clinical outcomes included the Timed Up-and-Go (TUG), Berg Balance Scale, and Brief Pain Inventory (BPI-DPN). Spatiotemporal, kinematic, and kinetic gait parameters were captured via 3D motion analysis. Given the small control sample, analyses prioritized within-group standardized effect sizes (Cohen's d z ) and clinical Minimal Clinically Important Difference (MCID) responder thresholds.
RESULTS: The force-based intervention yielded exceptional compliance. In the EG, FVT significantly reduced pain interference with walking (p = 0.015, d z =-0.54), and 44.4% of highly symptomatic participants achieved a clinically meaningful (≥3-point) reduction in worst pain. Functionally, continuous TUG times significantly improved (p = 0.033, d z =-0.93), resulting in 33.3% of high-risk patients successfully transitioning to a low fall-risk category (compared to a descriptive 0% in the CG). Biomechanically, these functional gains were accompanied by changes in gait biomechanics that may reflect improved gait performance, specifically, increased gait speed, reduced total double-support time (p = 0.014, d z =-0.53), and increased initial ground reaction forces, achieved without requiring compensatory proximal joint moments.
CONCLUSION: Targeted force-based manipulation via wearable FVT offers a highly feasible mechanism for pain relief and changes in gait biomechanics in DPN. By uncoupling neuropathic pain from functional ambulation, this intervention provides preliminary, hypothesis-generating evidence that supports the need for further investigation in fully powered trials.