Adaptive Gait Biofeedback With Participant-Held-Out Modeling and Participant-Specific Updating in Chronic Ankle Instability

# Adaptive Gait Biofeedback With Participant-Held-Out Modeling and Participant-Specific Updating in Chronic Ankle Instability
Source: [https://arxiv.org/abs/2610.07428](https://arxiv.org/abs/2610.07428)
[View PDF](https://arxiv.org/pdf/2610.07428)

> Abstract:Adaptive gait biofeedback may support repeated practice in chronic ankle instability, but its evaluation must address model performance and human response\. We evaluated a temporal convolutional classifier on protocol\-defined, angle\-derived GOOD/BAD gait\-cycle labels using participant\-held\-out leave\-one\-subject\-out \(LOSO\) cross\-validation in 20 participants\. Seven participants in the adaptive\-intervention group completed nine sessions over three weeks, with one motion\-capture recording analyzed per session\. Models updated after failed sessions were compared offline with their parent models on the same\-session validation subset used for candidate selection and the first subsequent adaptive\-session recording\. Frontal\-plane ankle angle was compared between the adaptive group and 10 sequentially enrolled controls at Baseline, Post, and 7\-day Retention\. Across 20 held\-out folds, mean fold\-level area under the receiver operating characteristic curve \(AUROC\) was 0\.948, sensitivity for angle\-threshold\-exceeding BAD cycles was 0\.941, and specificity for angle\-threshold\-meeting GOOD cycles was 0\.366\. Mean BAD\-class F1 was higher in candidate models by 0\.187 on the same\-session subset and 0\.118 on the first subsequent recording\. At Post, the adaptive group had a baseline\-adjusted frontal\-plane ankle angle 5\.168 degrees lower than controls \(95% confidence interval, 1\.766\-8\.569 degrees lower\); the Retention contrast was uncertain\. These findings characterize population\-model discrimination and offline participant\-specific updating during repeated biofeedback use, alongside a nonrandomized Post frontal\-plane ankle angle association\. They do not establish independent clinical gait classification or a causal benefit of updating\.

## Submission history

From: Jaeyoon Kim \[[view email](https://arxiv.org/show-email/0670c4f8/2610.07428)\] **\[v1\]**Mon, 5 Oct 2026 21:36:48 UTC \(1,679 KB\)