Haptic-based perception-empathy biofeedback system for balance rehabilitation in patients with chronic stroke: Concepts and initial feasibility study.

BACKGROUND: Most individuals have sensory disturbances post stroke, and these deficits contribute to post-stroke balance impairment. The haptic-based biofeedback (BF) system appears to be one of the promising tools for balance rehabilitation in patients with stroke, and the BF system can increase the objectivity of feedback and encouragement than that provided by a therapist. RESEARCH QUESTION: Studies in skill science indicated that feedback or encouragement from a coach or trainer enhances motor learning effect. Nevertheless, the optimal BF system (or its concept) which would refine the interpersonal feedback between patients and therapist has not been proposed. Thus, the purpose of this study was to propose a haptic-based perception-empathy BF system which provides information regarding the patient's center-of-foot pressure (CoP) pattern to the patient and the physical therapist to enhance the motor learning effect and validate the feasibility of this balance-training regimen in patients with chronic stroke. METHODS: This study used a pre-post design without control group. Nine chronic stroke patients (mean age: 64.4 ±â€¯9.2 years) received a balance-training regimen using this BF system twice a week for 4 weeks. Testing comprised quantitative measures (i.e., CoP) and clinical balance scale (Berg Balance Scale, BBS; Functional Reach Test, FRT; and Timed-Up and Go test, TUG). RESULTS AND SIGNIFICANCE: Post training, patients demonstrated marginally reduced postural spatial variability (i.e., 95% confidence elliptical area), and clinical balance performance significantly improved at post-training. Although the changes in FRT and TUG exceeded the minimal detectable change (MDC), changes in BBS did not reach clinical significance (i.e., smaller than MDC). These results may provide initial knowledge (i.e., beneficial effects, utility and its limitation) of the proposed BF system in designing effective motor learning strategies for stroke rehabilitation. More studies are required addressing limitations due to research design and training method for future clinical use.

The effect of a haptic biofeedback system on postural control in patients with stroke: An experimental pilot study.

BACKGROUND: Impaired balance in patients with hemiparesis caused by stroke is frequently related to deficits in the central integration of afferent inputs, and traditional rehabilitation reinforces excessive visual reliance by focusing on visual compensation. OBJECTIVE: The present study investigated whether a balance task involving a haptic biofeedback (BF) system, which provided supplementary vibrotactile sensory cues associated with center-of-foot-pressure displacement, improved postural control in patients with stroke. METHODS: Seventeen stroke patients were assigned to two groups: the Vibrotactile BF and Control groups. During the balance task (i.e., standing on a foam mat), participants in the Vibrotactile BF group tried to stabilize their postural sway while wearing the BF system around the pelvic girdle. In the Control group, participants performed an identical postural task without the BF system. RESULTS: Pre- and post-test measurements of postural control using a force plate revealed that the stability of bipedal posture in the Vibrotactile BF group was markedly improved compared with that in the Control group. CONCLUSIONS: A balance task involving a vibrotactile BF system improved postural stability in patients with stroke immediately. This confirms the potential of a haptic-based BF system for balance training, both in routine clinical practice and in everyday life.