Imperceptible Hydrogel Electronic Skin for Early Intervention in Neck Pain: Multimodal Wireless Monitoring of Cervical Kinematics and Muscle Fatigue

> 0.999). The first multimodal biosafety validation was conducted via fNIRS-based cortical pain mapping, confirming zero neural activation during wear. A cervical spine strain sensor and a trapezius sEMG array interface were integrated with flexible electronics for real-time wireless fatigue/posture alerts. This platform enables proactive neck pain management through precision biomechanical telemonitoring, advancing human-machine interfaces for tele-rehabilitation.