🤖 AI Summary
This paper addresses three core challenges hindering machine learning (ML) adoption in gait, running, and sports biomechanics: data scarcity, annotation bias, and lack of biophysical interpretability—highlighting bottlenecks in activity recognition, load prediction, and injury-risk modeling. To tackle these, we propose the first cross-modal ML applicability assessment framework, integrating supervised learning (CNNs/RNNs), weakly supervised action segmentation, physics-informed neural networks (PINNs), and uncertainty quantification. We derive 12 evidence-based implementation guidelines and five deployable validation protocols. Evaluated across six public biomechanics datasets, our framework reveals a 37–62% degradation in model robustness under real-world conditions versus controlled lab settings—underscoring critical generalization limitations. The work establishes a methodological foundation and practical roadmap for developing biomechanically grounded, trustworthy AI systems.