physioscience 2025; 21(S 03): S24
DOI: 10.1055/s-0045-1812404
Abstracts
Präsentationen/Presentations
PS 12

Reliability and Validity of Smartphone Measurement of Spinal Angular Amplitude and Velocity

Authors

  • G Christe

    1   HESAV – Haute École de Santé Vaud, HES-SO Haute École Spécialisée de Suisse occidentale, Lausanne, Switzerland

  • L Mourot

    2   HEIG-VD – Haute École d’Ingénierie et de Gestion du Canton de Vaud, HES-SO Haute École Spécialisée de Suisse occidentale, Yverdon-les-Bains, Switzerland

  • A Cerrito

    3   Bern University of Applied Sciences, Spinal Movement Biomechanics Group, Bern, Switzerland

  • A von Aesch

    3   Bern University of Applied Sciences, Spinal Movement Biomechanics Group, Bern, Switzerland

  • S Schmid

    3   Bern University of Applied Sciences, Spinal Movement Biomechanics Group, Bern, Switzerland

  • L Raileanu

    2   HEIG-VD – Haute École d’Ingénierie et de Gestion du Canton de Vaud, HES-SO Haute École Spécialisée de Suisse occidentale, Yverdon-les-Bains, Switzerland
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Background Spinal movement alterations have been identified as a potential contributor to low back pain (LBP) disability. However, current evidence is predominantly based on cross-sectional laboratory studies, limiting the understanding of how these alterations relate to the development or persistence of LBP. The availability of smartphones equipped with inertial measurement units offers a unique opportunity to assess spinal movement outside laboratory settings, enabling large-scale and repeated measurements in real-world environments. This study aimed to evaluate the within- and between-session reliability, as well as the concurrent validity, of a mobile application for measuring spinal amplitude and angular velocity during various tasks in real-world settings.

Methods Spinal movement amplitude and angular velocity were assessed using a smartphone held on the sternum across two sessions, with two measurement sets performed in the first session. A validated inertial sensor system served as a reference standard during the first session to assess concurrent validity. Participants completed a series of tasks, including flexion, extension, lateral flexion, rotation, and picking up an object from the floor. Intraclass Correlation Coefficient (ICC 2,1), standard error of the measurement (SEM), and minimal detectable change (MDC) were calculated for reliability. Pearson correlations (r) and Bland-Altman plots were used to test concurrent validity.

Results Thirty asymptomatic adults (50% male; 36.7 ± 14.07 years old) participated in the two sessions, one week apart. Within-session and between-session ICCs ranged from 0.59 to 0.93 and 0.66 to 0.92, respectively, for both amplitude and angular velocity. High correlations were observed between the smartphone and inertial sensors across most tasks (r = 0.64–0.96), except for lateral flexion amplitude, which ranged from r = 0.36 to 0.53.

Conclusion Smartphone-based measurement of spinal movement amplitude and angular velocity showed acceptable reliability and good concurrent validity in asymptomatic individuals, supporting its use for functional movement assessment in real-world settings. Future studies should confirm these findings in populations with LBP before implementing them clinically and in research.



Publication History

Article published online:
23 October 2025

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