Brief Research ReportsToward improving the specificity of perturbation-based training through assessment of dynamic balancing responses: a series of N-of-1 studies in subacute strokeZadravec, Matjaž; Olenšek, Andrej; Rudolf, Marko; Bizovičar, Nataša; Goljar, Nika; Matjačić, ZlatkoAuthor Information Research and Development Unit, University Rehabilitation Institute, Republic of Slovenia, Ljubljana, Slovenia Received 16 April 2021 Accepted 21 May 2021 Correspondence to Matjaž Zadravec, PhD, Research and Development Unit, University Rehabilitation Institute Republic of Slovenia, Linhartova 51, SI-1000 Ljubljana, Slovenia, Tel: +386 1 4758 206; e-mail: [email protected] International Journal of Rehabilitation Research: September 2021 - Volume 44 - Issue 3 - p 276-281 doi: 10.1097/MRR.0000000000000482 Buy Metrics Abstract Perturbation-based balance training (PBT) has been shown to improve reactive balancing abilities in chronic stroke. To inform future investigations in the subacute phase of stroke, the objective of this series of N-of-1 studies was to investigate the range of balancing responses to unexpected mechanical perturbations applied to the pelvis during walking on an instrumented treadmill before and after PBT training. Three subacute stroke subjects were assessed on each occasion with clinical tests and biomechanical measurements following perturbations applied in forward, backward, inward and outward directions. After 15 daily sessions of PBT, most clinical mobility outcomes showed improvements in all three subjects. Assessment of reactive balancing also showed improvements in all subjects when responding to perturbations in backward and inward directions whereas the changes following perturbations in forward and outward directions were subject-specific. The results suggest that PBT should be individually tailored to target balance deficiencies identified through a serial biomechanical assessment. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.