Wearable Spine Assessment in Adults With and Without Low Back or Neck Pain: A Single-Site Observational Feasibility and Validity Study

Low back and neck pain are among the most common, costly, and disabling musculoskeletal conditions in the United States and worldwide. Low back pain is the leading cause of years lived with disability globally, and neck pain is consistently within the top ten. Both are leading drivers of healthcare expenditure, exceeding spending on diabetes, heart disease, and cancer in some recent analyses. Despite this magnitude, the clinical assessment of spine function remains heavily reliant on subjective self-report and clinician examination, with limited use of objective, quantitative, point-of-care measurement tools.

Wearable sensors, particularly inertial measurement units (IMUs), have matured into a credible technology base for objective musculoskeletal assessment. Multiple research groups have published validation studies establishing the accuracy of IMU-based segmental kinematics against optical motion capture, and feasibility studies demonstrating the utility of wearable kinematics in occupational and clinical settings. Most published wearable-spine assessment work to date has focused on lumbar kinematics in isolation, with cervical kinematic assessment less well-developed and integrated full-spine kinematic assessment relatively rare.

Recent peer-reviewed work demonstrated the feasibility of using wearable IMU technology to objectively assess cervical and upper-back posture in high-risk professional populations during prolonged work tasks. This work established that IMU-based monitoring of upper-body kinematics is feasible in real-world settings and that the methodology generates objective, reproducible data suitable for biofeedback and longitudinal monitoring. The current study extends this established methodology to a broader spine assessment configuration covering cervical, thoracic, lumbar, and pelvic segments, and integrated with validated patient-reported outcome instruments to enable a holistic biopsychosocial assessment of spine function.

The objective of this study is to evaluate the ability of a wearable, multi-modal spine assessment system - AxiSens - to discriminate between adults with low back or neck pain and healthy controls, and to characterize its intra-rater repeatability and workflow feasibility. There is no investigational therapeutic intervention. All participants undergo the same wearable-sensor-based spine assessment procedures in a single on-site visit. Approximately 20 participants will be enrolled, comprising approximately 10 participants in the LBP/Neck Pain group and approximately 10 participants in the Control group.

To support intra-rater repeatability characterization within this single-visit design, the AxiSens wearable assessment is performed twice within the visit by a single trained operator, with sensor doffing and re-donning between the two assessments and a short rest interval. The two within-visit assessments support estimation of the intra-rater repeatability of AxiSens-derived kinematic and composite outcomes.