Two-Week Rehabilitation with Auditory Biofeedback Prosthesis Reduces Whole Body Angular Momentum Range during Walking in Stroke Patients with Hemiplegia: A Randomized Controlled Trial

A review of concurrent sonified biofeedback in balance and gait training

BACKGROUND

Sonified biofeedback is a subtype of auditory biofeedback that conveys biological data through specific non-verbal sounds. It can be designed to provide augmented biomechanical feedback in near-real-time when provided as "concurrent" biofeedback. As a practice that developed spanning across engineering and the arts, sonified biofeedback can extend beyond simple tones and beeps, towards more fully incorporating music in movement training. Sonified biofeedback may leverage the motivational aspects of music in movement training, the neuroplasticity benefits demonstrated from participation in music-based interventions, and neurological auditory-motor coupling, all while providing task-relevant cues to facilitate motor (re)learning. Sonified biofeedback may also provide similar benefits as rhythmic cueing (e.g., rhythmic auditory stimulation), or added benefits because sonified biofeedback does not impose a strict isochronous rhythm when it follows rhythms that are driven by outputs of the motor control system. In this review paper, the unique opportunity presented by concurrent sonified biofeedback as a movement training tool for balance and gait is introduced and discussed.

RESULTS AND DISCUSSION

This review paper brings together prior research from clinical, engineering, and artistic design sources using sonified biofeedback in balance and gait training across diverse end-users to highlight trends, reveal gaps in knowledge, and provide perspective for future work in the area. The goal was to review progress and critically assess research using sonified biofeedback during movement training for postural control or gait. 49 papers were selected based on their experimental investigation and statistical analyses of the effects of using sonified biofeedback to assist in movement training for feet-in-place balance tasks (20 papers) or gait tasks such as walking and running (29 papers). The sound design choices, experimental design features, and movement training results are summarized and reviewed. All but two studies reported at least one statistically significant positive effect of training with sonified biofeedback in biomechanical, clinical, or psychosocial measures. Conversely, only seven studies shared any negative effect on one biomechanical, clinical, or psychosocial measure (with five of these studies also reporting at least one other positive effect). After describing these encouraging findings, this review closes by sharing perspectives about future directions for designing and using sonified biofeedback in balance and gait training, and opportunities for more cohesive growth in this practice. One such suggestion is to pursue sonified designs and experimental designs that can translate to the neurorehabilitation field. This includes strategically selecting control groups and evaluation tasks to understand if improvements from training with one task transfer to additional relevant movement tasks. Additionally, it is important that future publications share details about the design processes and sound designs so researchers can more readily learn from one another.

CONCLUSIONS

Overall, this review shares the positive impact of using sonified biofeedback in balance and gait training. This review highlights the evidence of existing successes and potential for even more impactful future positive effects from using sonified biofeedback to help diverse populations with a spectrum of balance and mobility challenges and goals.

Feedback Interventions in Motor Recovery of Lateropulsion after Stroke: A Literature Review and Case Series

Lateropulsion is a post-stroke phenomenon marked by an active push of the body across the midline towards the more affected side and/or a resistance of the weight shift towards the less affected side. Within the mechanisms of treatment, feedback systems have been shown to be effective. The aim of the present study was to create a body of knowledge by performing a literature review on the use of feedback mechanisms in the treatment of lateropulsion and to report two cases of lateropulsion patients who had undergone feedback-based treatment.

METHODS

The review was performed across five different databases (Embase, Medline/PubMed, Scopus, Web of Science, and PEDro) up to February 2024, and haptic feedback intervention was incorporated into the case series (with lateropulsion and ambulation capacity as the main variables).

RESULTS

In total, 211 records were identified and 6 studies were included after the review of the literature. The most used feedback modality was visual feedback. In the case series, positive results were observed from the intervention, particularly in the recovery of lateropulsion and balance, as well as in the improvement of gait for one patient. Patients demonstrated good adherence to the intervention protocol without adverse effects.

CONCLUSIONS

Visual feedback is the most commonly used feedback modality in lateropulsion patients but other mechanisms such as haptic feedback also are feasible and should be taken into account. Larger sample sizes, extended follow-up periods, and the isolation of feedback mechanisms must be established to clarify evidence.

Regulation of whole-body angular momentum during human walking

In human walking, whole-body angular momentum (WBAM) about the body centre-of-mass is reportedly maintained in a small range throughout a gait cycle by the intersegmental cancellation of angular momentum. However, the WBAM is certainly not zero, which indicates that external moments applied from the ground due to ground reaction forces (GRFs) and vertical free moments (VFMs) counteract the WBAM. This study provides a complete dataset of the WBAM, each segmental angular momentum, and the external moments due to GRFs and VFMs during human walking. This is done to test whether (1) the three components of the WBAM are cancelled by coordinated intersegmental movements, and whether (2) the external moments due to GRFs and VFMs contribute only minimally to WBAM regulation throughout a gait cycle. This study demonstrates that WBAM is regulated in a small range not only by the segment-to-segment cancellation, but also largely through contributions by the GRFs. The magnitude of VFM is significantly smaller than the peak vertical moment generated by the GRFs; however, in the single-support phase during walking, the VFM is possibly critical for coping with the change in the vertical WBAM due to force perturbations and arm or trunk movements.

A simplified model for whole-body angular momentum calculation

The capability to monitor gait stability during everyday life could provide key information to guide clinical intervention to patients with lower limb disabilities. Whole body angular momentum (Lbody) is a convenient stability indicator for wearable motion capture systems. However, Lbody is costly to estimate, because it requires monitoring all major body segment using expensive sensor elements. In this study, we developed a simplified rigid body model by merging connected body segments to reduce the number of body segments, which need to be monitored. We demonstrated that the Lbody could be estimated by a seven-segment model accurately for both people with and without lower extremity amputation.

Malignant Isolated Cortical Vein Thrombosis as the Initial Manifestation of Primary Antiphospholipid Syndrome: Lessons on Diagnosis and Management From a Case Report

Background

Antiphospholipid syndrome (APS) with isolated cortical vein thrombosis (ICoVT) is an extremely rare but potentially malignant entity. It is particularly challenging to diagnose APS-related ICoVT because of the non-specific clinical manifestations and the frequent absence of typical neuroimaging. Moreover, there is currently limited knowledge on the clinical features and management strategies for the condition. Delays in diagnosis and treatment may lead to life-threatening consequences.

Case Presentation

We present a rare case of a 74-year-old Chinese woman who presented with sudden onset of headache and right arm weakness that mimicked acute ischemic stroke. Her initial computed tomography was unremarkable, and intravenous thrombolysis was performed. Serial neuroimages confirmed ICoVT 4 days after symptom onset, and low-molecular-weight heparin (LMWH) was started at a dose of 0.4 ml twice per day, according to the 2019 Chinese guidelines. The workup for the predisposing causes of ICoVT revealed triple positivity APS. LMWH dose was adjusted according to the anti-Xa chromogenic assay. However, the patient’s condition deteriorated rapidly, and there was a progressive enlargement of the venous infarction despite treatment with anticoagulants. Transtentorial herniation developed on day 12, and decompressive craniectomy was immediately performed. The patient’s symptoms did not improve significantly after surgery, and she remained aphasic and hemiplegic at the 3-month follow-up, with a modified Rankin Scale score of 5.

Conclusion

ICoVT is a rare yet potentially fatal manifestation of APS, and its diagnosis and treatment are extremely challenging. Timely diagnosis, prompt treatment, and close monitoring are essential to improve the clinical prognosis of patients with APS-related ICoVT.