A Novel Body Weight-Supported Postural Perturbation Module for Gait and Balance Rehabilitation After Stroke: Preliminary Evaluation Study

Abstract

Background: Impaired balance regulation after stroke puts patients and therapists at risk of 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 to accommodate complex exercises that require more freedom of movement.

Objective: This study aims to evaluate the effect of a new balance perturbation module, which is directly integrated into a track-mounted BWSS, on balance impairments secondary to acute stroke.

Methods: This unblinded quasi-randomized controlled preliminary study was conducted 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 (out of 56) or greater. Over a 2-week period, consented participants completed 8 BWSS or BWSS with perturbation (BWSS-P) treatment sessions; study activities were incorporated into regular treatment to avoid disruption of their normal care. Although both groups conducted the same balance and gait activities during their treatment sessions, the BWSS-P sessions included lateral, anterior, and posterior balance perturbations. Pre- and postintervention BBS and Activities-Specific Balance Confidence (ABC) assessments were the primary outcome measures collected. Institutional BBS data from the year before installation of the track-mounted BWSS were retrospectively included as a post hoc historical standard of care comparison.

Results: The improved postintervention BBS and ABC assessment scores showed that all participants benefited from therapy (P<.001 for all pre- and postintervention comparisons). The average BBS percent change for the BWSS-P sample (n=14) was 66.95% (SD 43.78%) and that for the BWSS control sample (n=15) was 53.29% (SD 24.13%). These values were greater than those for the standard of care group (n=30; mean 28.31%, SD 17.25%; P=.02 and P=.005 respectively), with no difference among the BWSS groups (P=.67). ABC score changes were also similar among the preintervention and postintervention BWSS groups (P=.94 and P=.92, respectively).

Conclusions: Both BWSS groups demonstrated similar BBS and ABC score improvements, indicating that balance perturbations were not detrimental to postacute stroke rehabilitation and were safe to use. These data provide strong rationale and baseline data 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.

Trial registration: ClinicalTrials.gov NCT04919161; https://ichgcp.net/clinical-trials-registry/NCT04919161.

Keywords: Activities-Specific Balance Confidence Scale; balance perturbation; body weight support system; gait and ambulation; long-term acute care hospital, Berg Balance Scale; occupational therapy; physical therapy; postural balance; postural perturbation; stroke rehabilitation.

Conflict of interest statement

Conflicts of Interest: None declared.

©Amanda Meyer, Henry Charles Hrdlicka, Erica Cutler, Jill Hellstrand, Emily Meise, Kaitlyn Rudolf, Pete Grevelding, Matthew Nankin. Originally published in JMIR Rehabilitation and Assistive Technology (https://rehab.jmir.org), 01.03.2022.

Figures

Figure 1

Participant flowchart. Of the 336 patients admitted for stroke rehabilitation that were assessed for study eligibility, 14.9% (50/336) were approached for study inclusion. Ultimately, 64% (32/50) of participants were enrolled in the study and assigned to either the body weight support system (BWSS) control or body weight support system with perturbation (BWSS-P) groups. During the study, 13% (4/32) of participants withdrew from the study early; 50% (2/4) because of early discharge, 25% (1/4) because of a flare-up of a pre-existing orthopedic condition, and 25% (1/4) because of an acute ankle sprain. Data from 9% (3/32) of participants was excluded from the final analysis.

Figure 2

Perturbation level progression. From the body weight support system, the highest perturbation level achieved was recorded for each participant, after each therapy session. Each participant who completed the study successfully increased their perturbation level between the first and last study-related therapy session (A). The perturbation level progression for the participants that completed the study could be broken down into three categories: low responders (B), moderate responders (C), and high responders (D). P values shown are for the comparison of session 1 and session 8 perturbation levels.

Figure 3

Berg Balance Scale assessment (BBS). Participant’s pre- and postintervention BBS assessment scores were used to track their improvement and response to the therapy. In addition to the body weight support system (BWSS) control and body weight support system with perturbation (BWSS-P) protocols, data from 2018, before the implementation of the BWSS, served as a historical standard of care (SOC) comparison group. Raw scores were first examined in aggregate (A). BBS percent change was calculated for each participant to show the magnitude of change between pre- and postintervention scores (B). In panel A, P values are shown only for comparisons that are significantly different or of clinical interest. Box plots represent the median and the 25% and 75% quartiles, respectively. The whiskers extend 1.5 and −1.5 of the IQR, respectively; circle symbols reflect data points beyond the 1.5 interquartile ranges; + symbols represent the mean; SOC: n=30, BWSS control: n=14 to 15, BWSS-P: n=13 to 14.

Figure 4

Activities-Specific Balance Confidence (ABC) scale assessment. The ABC scale was given to participants before and after the intervention to gauge their confidence in performing daily tasks. The box plot represents the median and the 25% and 75% quartiles, respectively. The whiskers extend 1.5 and −1.5 of the IQR, respectively; + symbols represent the mean; body weight support system (BWSS) control: n=14 to 15, body weight support system with perturbation (BWSS-P): n=13 to 14.