Validity of IMU sensors for assessing features of walking in laboratory and outdoor environments among older adults

Matikainen-Tervola, Emmi, Cronin, Neil ORCID: https://orcid.org/0000-0002-5332-1188, Aartolahti, Eeva, Sihvonen, Sanna, Sansgiri, Sailee, Finni, Taija, Mattila, Olli-Pekka and Rantakokko, Merja (2024) Validity of IMU sensors for assessing features of walking in laboratory and outdoor environments among older adults. Gait & Posture, 114. pp. 277-283. doi:10.1016/j.gaitpost.2024.10.013

Text 14955 Matikainen-Tervola et al (2025) Validity of IMU sensors.pdf - Accepted Version Restricted to Repository staff only until 21 October 2025. (Publisher Embargo). Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (411kB)

Abstract

Introduction IMU sensors (three-dimensional accelerometer, gyroscope and magnetometer) enable assessment of walking in older adults outside the laboratory. We studied whether IMUs are valid for detecting walking parameters (step events, time, length, and cadence) in a laboratory and outdoors on a level surface in older adults. Methods This validation study is part of a larger cross-sectional study. Twenty-six participants (mean age 76 years, 65 % female) walked on a treadmill indoors and on a sport track outdoors at self-selected speed. IMUs were attached laterally on the shanks and on the lower back at the level of L3-L4. Initial contact (IC) and step lengths were also estimated using acceleration signals (vertical, antero-posterior) from the pelvic IMU. Terminal contact (TC) was determined from the shank IMU sagittal angular velocity. For step length, inverted pendulum model and participant’s leg length (0.53 x height) was used. Step duration was calculated from IC to the opposite leg IC and stride duration from IC to next ipsilateral IC. Cadence was calculated as steps/min. As reference data, 3D motion capture was used in the laboratory and a high-speed video camera outdoors. Intraclass correlation coefficients (ICC), root mean squared errors (RMSE), typical errors and Bland-Altman plots were calculated and drawn. Results When comparing IC timing between IMU and reference data, mean bias was 0.031 s in the laboratory and −0.004 s outdoors, and for TC −0.057 s and −0.070 s respectively. Step and stride duration and cadence showed ICC values >0.80 and mean bias was <0.005 s for step and stride durations and <0.05 steps/min for cadence in both environments. Step length ICC values were <0.40 in the laboratory and outdoors. Significance IMUs can be used to monitor temporal walking variables in older adults and may be useful for rehabilitation interventions and functional capacity assessment.

Item Type:	Article
Article Type:	Article
Uncontrolled Keywords:	Older adults; Gait assessment; Wearable device; Validity; Outdoor walking
Subjects:	G Geography. Anthropology. Recreation > GV Recreation Leisure > GV191.2 Outdoor Life. Outdoor recreation. Q Science > QP Physiology
Divisions:	Schools and Research Institutes > School of Education and Science
Depositing User:	Charlotte Crutchlow
Date Deposited:	10 Apr 2025 09:10
Last Modified:	10 Apr 2025 09:15
URI:	https://eprints.glos.ac.uk/id/eprint/14955

University Staff: Request a correction | Repository Editors: Update this record