Toward improving the specificity of perturbation-based training through assessment of dynamic balancing responses: a series of N-of-1 studies in subacute stroke

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.

Real-time cross-step detection using center-of-pressure based algorithm

“…The CoP data was obtained during our previous studies, assessing dynamic balancing responses, in which participants experienced perturbing force impulses applied to the pelvis while walking on an instrumented treadmill [3,16,27,29]. The perturbing force impulses, directed mediolaterally, provoke reactive balance responses that often led to cross-stepping behaviour following the onset of the perturbation.…”

“…Both thresholds T U and T L are also limited between minimal T min and maximal value T max as shown in Eq. (3). By utilizing Eq.…”

“…Gait analysis plays a crucial role in understanding human locomotion and assessing the effectiveness of rehabilitation therapies [1][2][3]. Accurate and reliable real-time detection of gait events, such as heel strikes (HS) and toe-offs (TO), is essential for monitoring various gait parameters as well as for provision of realtime biofeedback during training of walking.…”