Unpredictable gait perturbation training improves balance and gait abilities more than gait training without perturbations in individuals post-stroke

Abstract

Balance perturbation training is a promising rehabilitation approach, but limited research is available on its effectiveness for balance post-stroke. The aim of this study was to compare the effects of training with and without unpredictable gait perturbations, on dynamic balance and gait abilities in individuals post-stroke. Nineteen stroke individuals were assigned to two groups: perturbation training (PT) and no-perturbation training (nPT), and attended 9 training sessions over 3 weeks using a split-belt treadmill. For PT, perturbations were produced by changing the speed of one of the belts during stance phase every 8 to 16 steps. The intensity of the perturbations increased progressively between sessions according to participants’ tolerance. The duration of the training sessions in nPT, i.e. without perturbation, was matched with a PT subject with similar speed. The effects of the training programs on dynamic balance (Mini-BESTest), balance confidence (ABC Scale), gait speed [10-meter walk test (10MWT)], knee extensors strength (dynamometry), and reintegration into social activities [Reintegration to Normal Living Index (RNLI)] were evaluated and compared using Anovas and t -tests. Mini-BESTest [+4.0 (±5.2)/28 points, P = 0.005], ABC scale [+4.4% (±6.0), P = 0.026], 10MWT at faster speed [+0.17 (±0.15) m/s, P = 0.009], non-paretic knee extensors [+37.2 (±41.7) Nm, P = 0.056], and RNLI [−3.4 (±2.9)/11, P = 0.04] increased significantly with PT, with no significant changes on 10MWT at self-selected speed (0.13 (±0.19) m/s, P = 0.065) and maximum strength generation on the paretic side (+32.7 [±41.3] Nm, P = 0.081). Mini-BESTest, gait speed (self-selected and faster) and maximum knee extensors strength of paretic side in PT changed significantly in comparison to nPT which did not show any improvement. Results support the clinical effectiveness of unpredictable gait perturbation training over walking on the treadmill in improving gait and dynamic balance after stroke. Impact on fall risk should be evaluated in a future clinical study.