Using wearable sensors to classify subject-specific running biomechanical gait patterns based on changes in environmental weather conditions

• Published in: PloS one Vol. 13; no. 9; p. e0203839
• Main Authors: Ahamed, Nizam Uddin, Kobsar, Dylan, Benson, Lauren, Clermont, Christian, Kohrs, Russell, Osis, Sean T., Ferber, Reed
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.09.2018; Public Library of Science (PLoS)
• Subjects: Adult; Air temperature; Algorithms; Biology and Life Sciences; Biomechanical Phenomena - physiology; Biomechanics; Biometeorology; Biophysics; Braking; Care and treatment; Change detection; Classification; Earth Sciences; Environmental aspects; Environmental changes; Female; Gait; Gait - physiology; Gait Analysis - instrumentation; Gait Analysis - methods; Health aspects; Humans; Impact tests; Information processing; Learning algorithms; Machine learning; Male; Marathons; Medicine and Health Sciences; Middle Aged; Musculoskeletal diseases; Overuse injuries; Pelvis; Prediction models; Risk analysis; Risk factors; Running; Running - classification; Running - physiology; Sensors; Signal processing; Studies; Vertical oscillations; Wearable Electronic Devices; Wearable technology; Weather; Weather conditions; Alberta Canada; Canada; Calgary Alberta Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0203839

Running-related overuse injuries can result from a combination of various intrinsic (e.g., gait biomechanics) and extrinsic (e.g., running surface) risk factors. However, it is unknown how changes in environmental weather conditions affect running gait biomechanical patterns since these data cannot be collected in a laboratory setting. Therefore, the purpose of this study was to develop a classification model based on subject-specific changes in biomechanical running patterns across two different environmental weather conditions using data obtained from wearable sensors in real-world environments. Running gait data were recorded during winter and spring sessions, with recorded average air temperatures of -10° C and +6° C, respectively. Classification was performed based on measurements of pelvic drop, ground contact time, braking, vertical oscillation of pelvis, pelvic rotation, and cadence obtained from 66,370 strides (~11,000/runner) from a group of recreational runners. A non-linear and ensemble machine learning algorithm, random forest (RF), was used to classify and compute a heuristic for determining the importance of each variable in the prediction model. To validate the developed subject-specific model, two cross-validation methods (one-against-another and partitioning datasets) were used to obtain experimental mean classification accuracies of 87.18% and 95.42%, respectively, indicating an excellent discriminatory ability of the RF-based model. Additionally, the ranked order of variable importance differed across the individual runners. The results from the RF-based machine-learning algorithm demonstrates that processing gait biomechanical signals from a single wearable sensor can successfully detect changes to an individual's running patterns based on data obtained in real-world environments.