Analytical validation of mobile gait measurement systems for sports rehabilitation: sensors, reference methods, and performance metrics

Abstract The increasing incidence of sports-related injuries highlights the need for effective rehabilitation strategies, with gait analysis playing a central role in monitoring functional recovery and informing return-to-sport decisions. Mobile health technologies, including wearable sensors, smartphone applications, and camera-based motion capture systems, provide viable alternatives to conventional laboratory gait assessment by enabling real time, remote, and ecologically valid evaluations. Despite their potential, clinical integration remains limited due to inconsistent and frequently inadequate analytical validation. This review systematically evaluates current mobile health technologies for gait analysis in sports injury rehabilitation. It outlines the biomechanical principles underpinning gait assessment, summarizes the core technical capabilities of contemporary mobile systems, and critically examines validation approaches such as the V3 framework. Key sports injuries, including anterior cruciate ligament reconstruction, Achilles tendinopathy, chronic ankle instability, and patellofemoral pain, are analyzed with respect to characteristic gait alterations and the applicability of mobile assessment tools in their rehabilitation. The review reveals considerable heterogeneity in validation quality, underscoring the necessity for context specific, parameter driven validation protocols. It further discusses technological, methodological, and regulatory barriers to widespread implementation. Practical recommendations are provided to harmonize validation standards, increase algorithmic transparency, and enhance clinical usability. Strengthening analytical rigor and interdisciplinary collaboration will support the development of reliable, scalable gait monitoring solutions that advance personalized rehabilitation and promote safe return to sport in athletic populations.