Continuous Non-Invasive Assessment of Segmental Cervical Motion: A Narrative Review and Validation Framework

Area of Science:

• Biomechanics
• Digital Health
• Musculoskeletal Disorders

Background:

• Modern lifestyles, including digital device use and prolonged static postures, contribute to neck pain and dysfunction.
• Current diagnostic methods for cervical disorders rely heavily on static imaging and brief clinical exams, which inadequately capture dynamic functional deficits.

Purpose of the Study:

• To evaluate the limitations of current diagnostic approaches for contemporary cervical disorders.
• To explore segmental cervical motion as a functional target for clinical assessment.
• To propose a framework for continuous, non-invasive cervical functional assessment.

Main Methods:

• Review of evidence from static imaging, dynamic radiography, laboratory motion analysis, wearable inertial sensing, and markerless video.
• Synthesis of current capabilities and translational limitations of various assessment methods.
• Development of a four-layer framework for continuous non-invasive cervical functional assessment.

Main Results:

• Dynamic radiographic methods offer anatomical specificity but are not scalable for longitudinal monitoring.
• Wearable and video-based approaches are suitable for real-world assessment but capture external kinematics with inference uncertainties.
• Segmental cervical motion signatures are proposed as candidate digital measures for longitudinal monitoring.

Conclusions:

• Current diagnostic methods are ill-suited for the dynamic nature of many cervical disorders.
• A proposed four-layer framework integrates multimodal external signals to infer segmental cervical behavior for continuous monitoring.
• Segmental motion signatures require rigorous validation, uncertainty reporting, and demonstrated clinical value for effective implementation.