Instrumented Functional Test for Objective Outcome Evaluation of Balance Rehabilitation in Elderly Fallers: A Clinical Study

Abstract

<b><i>Introduction:</i></b> Observational tests, e.g., the Berg Balance Scale (BBS) are widely used for balance evaluation in the elderly fallers. However, they do not allow objective outcome evaluation of rehabilitative interventions. This study aimed to investigate, in a clinical setting, the use of inertial measurement units (IMUs) integrated into the BBS test for objective outcome evaluation of balance rehabilitation in elderly fallers compared to conventional BBS scores. <b><i>Methods:</i></b> Thirty-six elderly fallers were recruited from the in-patient population of a geriatrics Clinic. Participants performed the BBS test while wearing 3 IMUs placed on the sternum, sacrum, and tibia of the dominant leg following admission to the clinic. Subsequently, they completed a rehabilitation program for 2–4 weeks. They performed a similar test before their discharge. The physical therapist recorded the BBS scores at both sessions, and the sensor data of the 2-min quiet standing task (BBS task 2) were extracted for objective balance evaluation. Moreover, eleven young adults were recruited to perform a 2-min quiet standing test while wearing the same IMUs. Center-of-pressure (COP) and segmental center-of-mass (COM) accelerations were calculated to estimate time-domain, frequency-domain, and intersegment coordination biomarkers of balance. <b><i>Results:</i></b> COP time- and frequency-domain measures, COM acceleration time-domain measures, and intersegment coordination measures could identify age-related changes in balance of seniors compared to young adults (<i>p</i> &#x3c; 0.05). Moreover, balance biomarkers of senior adults exhibited a reduced sway acceleration and jerkiness in the medial-lateral direction post-rehabilitation (<i>p</i> &#x3c; 0.05). Although the total BBS scores increased post-rehabilitation, sway displacement and velocity did not significantly improve. We observed a significant association between pelvis-leg coordination at high sway oscillations and the total BBS scores pre- and post-rehabilitation. <b><i>Conclusion:</i></b> IMUs enable not only the characterization of underlying causes of impaired balance but also the identification of improved and yet impaired aspects of balance post-rehabilitation. Hence, IMUs allow us to characterize risk factors post-rehabilitation in elderly fallers, whereas the BBS scores only show changes in overall balance. It is crucial to objectively evaluate the effectiveness of such interventions to reduce future falls and their adverse consequences. Therefore, instrumented balance assessment is recommended since it can provide quantitative and objective measures for clinical outcome evaluations.