Evaluation of head posture using an inertial measurement unit

Area of Science:

• Biomechanics
• Medical Instrumentation
• Human Movement Analysis

Background:

• Head posture assessment is crucial for diagnosing and managing various musculoskeletal conditions.
• Current methods like the cervical range of motion (CROM) device serve as a gold standard but can be cumbersome.
• Inertial measurement units (IMUs) offer a potential for more accessible and objective head posture measurement.

Purpose of the Study:

• To evaluate the accuracy of IMUs for measuring head posture against the established CROM device.
• To assess the reproducibility of head posture measurements using IMUs.
• To determine the validity of IMUs as an index test for head posture analysis.

Main Methods:

• The study compared IMU measurements to a CROM device (gold standard) in both in vitro and in vivo settings.
• Thirty healthy young adults participated in reproducibility tests, performing head movements to four locations across two sessions.
• Measurements were analyzed for correlation and absolute mean differences to assess accuracy and reliability.

Main Results:

• Excellent correlation (r=0.99) was observed between IMU and CROM devices in vitro, with a small mean difference (0.45° ± 0.58°).
• In vivo testing also showed excellent correlation (r=0.99) with a mean difference of 0.88° ± 1.20°.
• Reproducibility tests yielded moderate to good correlation coefficients (r=0.55 to 0.89) and excellent reliability (ICC 0.74 to 0.96).

Conclusions:

• Calibrated IMU sensors demonstrate high accuracy and reliability for measuring head posture.
• IMUs show significant potential as a valid and reproducible tool for head posture analysis.
• These findings support the use of IMUs as an adequate index test in clinical and research applications.