Use Of An Instrumented In-shoe Sensor For Propulsion Biofeedback In Able-bodied And Gait-impaired Individuals

PURPOSE: Post-stroke hemiparesis and diabetic peripheral neuropathy (DPN) commonly result in reduced propulsion during gait, measured as anterior ground reaction force (AGRF). Reduced propulsion results in decreased gait speed and impaired functional ambulation. The loadsol® (novel electronics inc., Saint Paul, MN) is an in-shoe sensor that may be able to provide propulsion biofeedback in a clinical setting. METHODS: Seventeen able-bodied (AB) individuals (7 M, 10 F, age = 26.5 ± 3.5 y), 12 participants with chronic post-stroke hemiparesis (6 M, 6 F, age = 57.0 ± 12.0 y, 70.0 ± 57.2 months post-stroke), and 5 individuals with DPN (5 F, age = 57.4 ± 4.3 y) walked on a split-belt instrumented treadmill with 3-sensor (hindfoot, midfoot, forefoot) loadsols® in both shoes. Following a baseline (BS) walking trial, loadsol® was used to provide auditory and haptic biofeedback with a 3-10% increase in unilateral forefoot plantar force in the dominant foot in AB, the paretic limb in post-stroke participants, and the more impaired limb in DPN. Peak forefoot loadsol® plantar force (N) and peak forceplate AGRF (N) were calculated for each trial. One-way ANOVAs with post-hoc t-tests were performed to compare BS to biofeedback trials. RESULTS: Auditory and haptic biofeedback induced significant increases in plantar force measured by the loadsol® in AB (BS = 694.6 ± 203.3, auditory = 753.8 ± 216.7, haptic = 758.6 ± 202.8, p < .001), stroke (BS = 497.9 ± 167.3, auditory = 591.5 ± 156.7, haptic = 597.8 ± 147.4, p = .017), and DPN (BS = 533.5 ± 188.1, auditory = 730.2 ± 225.7, haptic = 657.8 ± 243.6, p = .044) and AGRF measured by the forceplate in AB (BS = 142.3 ± 57.4, auditory = 225.7 ± 136.8, haptic = 218.1 ± 133.4, p < .001), stroke (BS = 81.6 ± 34.4, auditory = 102.1 ± 39.3, haptic = 98.0 ± 40.9, p = .001), and DPN (BS = 91.5 ± 34.2, auditory = 148.6 ± 34.8, haptic = 140.5 ± 42.9, p = .002). There were no differences between audio and haptic biofeedback trials. CONCLUSIONS: Both auditory and haptic biofeedback delivered by the loadsol® resulted in increased propulsion during gait in AB, stroke, and DPN participants, showing that the loadsol® may be a feasible device to modify gait in individuals with decreased propulsion. NICHD K01HD107294, NIDDK P30DK111024