160871 20251017144554.0 doi 10.3390/s25082480 sideral 144045 ART-2025-144045 eng Echevarría-Polo, Marcos Universidad de Zaragoza Variability and reliability of the Axivity AX6 accelerometer in technical and human motion conditions 2025 Access copy available to the general public Unrestricted This study aimed to evaluate the intra- and inter-instrument variability and reliability of the Axivity AX6 accelerometer under controlled technical conditions and human motion scenarios. In the first experiment, 12 accelerometers were affixed to a vibration platform and tested at four frequencies (2.2, 3.2, 6.5, and 9.4 Hz) along three axes to assess frequency- and axis-dependent variability. In the second experiment, four AX6 accelerometers were simultaneously placed on a subject’s wrist and tested under four human motion conditions (walking at 4 km·h−1 and 6 km·h−1 and running at 8 km·h−1 and 10 km·h−1). Results demonstrated low intra- and inter-instrument variability (CVintra: 3.3–4.5%; CVinter: 6.3–7.7%) with high reliability (ICC = 0.98). Similar results were observed in human motion conditions (CVintra: 5.3–8.8%; CVinter: 7.1–10.4%), with ICC values of 0.98 for combined devices, and 0.99 for each device individually. Despite statistically significant differences (p < 0.05) between devices in human motion all conditions, the variations remained below the minimal clinically significant difference threshold. These findings indicate that under technical conditions on a vibrating platform, and within the range of typical human accelerations, the Axivity AX6 is a reliable tool for measuring accelerations representative of physical activity. However, further research is necessary to validate its performance under free-living conditions. info:eu-repo/grantAgreement/ES/DGA/T39-23R info:eu-repo/grantAgreement/ES/MICINN/PID2022-140556OB-I00 info:eu-repo/grantAgreement/EUR/MICINN/TED2021-130459B-I00 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Marín, Pedro J. Pueyo, Esther Universidad de Zaragoza (orcid)0000-0002-1960-407X Ramos Maqueda, Javier Universidad de Zaragoza Garatachea, Nuria Universidad de Zaragoza (orcid)0000-0001-8374-9081 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 1007 610 Universidad de Zaragoza Dpto. Medicina, Psiqu. y Derm. Area Medicina 5008 800 Universidad de Zaragoza Dpto. Ingeniería Electrón.Com. Área Teoría Señal y Comunicac. 25, 8 (2025), 2480 [11 pp.] Sensors Sensors 1424-8220 1552153 http://zaguan.unizar.es/record/160871/files/texto_completo.pdf Versión publicada 2493976 http://zaguan.unizar.es/record/160871/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:160871 articulos driver 2025-10-17-14:12:32 ARTICLE