Inducing Body Weight Supported Postural Perturbations during Gait and Balance Exercises to Improve Balance after Stroke: A Pilot Study (Preprint)

BACKGROUND Impaired balance-regulation after stroke put patients and therapists at risk for injury during rehabilitation. Body-weight-support systems (BWSSs) minimize this risk and allow patients to safely practice balance activities during therapy. Treadmill based balance perturbation systems with BWSSs are known to improve balance in patients with age or disease related impairments. However, these stationary systems are unable accommodate complex exercises requiring more freedom of movement. OBJECTIVE To evaluate the effect of a new balance perturbation module, which is directly integrated to a track-mounted BWSS, has on impaired balance secondary to acute stroke. METHODS This unblinded quasi-randomized controlled pilot study took place in a rehabilitation focused long-term acute care hospital. Participants were recruited from stroke rehabilitation inpatients with an admission Berg Balance Scale (BBS) score of 21/56 or greater. Over a two-week period, consented participants completed eight BWSS or BWSS with perturbation (BWSS-P) treatment sessions; study activities were incorporated into regular treatment so as to not disrupt their care. While both groups conducted the same balance and gait activities during their treatment sessions, the BWSS-P sessions included lateral and anterior/posterior resistive or assistive balance perturbations. Pre- and post-intervention BBS and Activities-Specific Balance-Confidence (ABC) assessments were the primary outcome measures collected. Institutional BBS data from fiscal-year 2018, prior to installation of the track mounted BWSS, was used as a historical standard-of-care (SOC) baseline. RESULTS Improved post-intervention BBS and ABC assessment scores showed all participants benefited from therapy (p<0.05). The BBS percent-change of the BWSS-P [mean(SD)n] [66.95%(43.78%)14] and BWSS control [53.29%(24.13%)15] were greater than the SOC group [28.31%(17.25%)30] (p<0.05), with no difference between BWSS groups (p=0.6669); ABC percent score-changes were also similar (p>0.800). CONCLUSIONS Both BWSS groups demonstrated similar BBS and ABC score improvements, indicating balance perturbations are not detrimental to post-acute stroke rehabilitation and are safe to use. This data provides strong rationale for conducting a larger follow-up study to further assess if this new perturbation system provides additional benefit to the rehabilitation of gait and balance impairments following stroke. CLINICALTRIAL ClinicalTrials.gov [NCT04919161]