{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T21:47:34Z","timestamp":1780609654593,"version":"3.54.1"},"reference-count":10,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2019,6,29]],"date-time":"2019-06-29T00:00:00Z","timestamp":1561766400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>There is interest in using wearable sensors to measure infant movement patterns and physical activity, however, this approach is confounded by caregiver motion. The purpose of this study is to estimate the extent that caregiver motion confounds wearable sensor data in full-day studies of infant leg movements. We used wearable sensors to measure leg movements of a four-month-old infant across 8.5 hours, during which the infant was handled by the caregiver in a typical manner. A researcher mimicked the actions of the caregiver with a doll. We calculated 7744 left and 7107 right leg movements for the infant and 1013 left and 1115 right \u201cleg movements\u201d for the doll. In this case, approximately 15% of infant leg movements can be attributed to background motion of the caregiver. This case report is the first step toward removing caregiver-produced background motion from the infant wearable sensor signal. We have estimated the size of the effect and described the activities that were related to noise in the signal. Future research can characterize the noise in detail and systematically explore different methods to remove it.<\/jats:p>","DOI":"10.3390\/s19132886","type":"journal-article","created":{"date-parts":[[2019,7,1]],"date-time":"2019-07-01T03:23:59Z","timestamp":1561951439000},"page":"2886","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Quantifying Caregiver Movement when Measuring Infant Movement across a Full Day: A Case Report"],"prefix":"10.3390","volume":"19","author":[{"given":"Judy","family":"Zhou","sequence":"first","affiliation":[{"name":"Infant Neuromotor Control Laboratory, Division of Biokinesiology and Physical Therapy, University of Southern California, 1540 Alcazar St, CHP 155, Los Angeles, CA 90089, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sydney Y.","family":"Schaefer","sequence":"additional","affiliation":[{"name":"Motor Rehabilitation and Learning Laboratory, School of Biological and Health Systems Engineering, Arizona State University, 1151 S Forest Ave Tempe, AZ 85287, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2531-5394","authenticated-orcid":false,"given":"Beth A.","family":"Smith","sequence":"additional","affiliation":[{"name":"Infant Neuromotor Control Laboratory, Division of Biokinesiology and Physical Therapy and Department of Pediatrics, University of Southern California, 1540 Alcazar St, CHP 155, Los Angeles, CA 90089, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"19006","DOI":"10.3390\/s150819006","article-title":"Daily quantity of infant leg movement: Wearable sensor algorithm and relationship to walking onset","volume":"15","author":"Smith","year":"2015","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Trujillo-Priego, I.A., Lane, C.J., Vanderbilt, D., Deng, W., Loeb, G., Shida, J., and Smith, B. (2017). Development of a wearable sensor algorithm to detect the quantity and kinematic characteristics of infant arm movement bouts produced across a full day in the natural environment. Technologies, 5.","DOI":"10.3390\/technologies5030039"},{"key":"ref_3","first-page":"1","article-title":"Kinematic characteristics of infant leg movements produced across a full day","volume":"4","author":"Smith","year":"2017","journal-title":"JRATE"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/JTEHM.2019.2893223","article-title":"Identification of developmental delay in infants using wearable sensors: Full-day leg movement statistical feature analysis","volume":"7","author":"Abrishami","year":"2019","journal-title":"IEEE J. Transl. Eng. Health Med."},{"key":"ref_5","unstructured":"Goodfellow, D., Zhi, R., Funke, R., Pulido, J.C., Mataric, M., and Smith, B.A. (2018, January 19\u201323). Predicting Infant Motor Development Status Using Day Long Movement Data from Wearable Sensors. Proceedings of the KDD Workshop on Machine Learning for Healthcare and Medicine (KDD\u201918), London, UK."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"17","DOI":"10.12688\/gatesopenres.12813.1","article-title":"Relationships between full-day arm movement characteristics and developmental status in infants with typical development as they learn to reach: An observational study","volume":"2","author":"Lane","year":"2018","journal-title":"Gates Open Res."},{"key":"ref_7","first-page":"1","article-title":"Determining if wearable sensors affect infant leg movement frequency","volume":"5","author":"Jiang","year":"2017","journal-title":"Dev. Neurorehabil."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.infbeh.2008.12.003","article-title":"Mechanical measurement of infant activity: A cautionary note","volume":"32","author":"Worobey","year":"2009","journal-title":"Infant Behav. Dev."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1123\/jpah.2016-0395","article-title":"Minimum Accelerometer Wear Time in Infants: A Generalizability Study","volume":"14","author":"Pitchford","year":"2017","journal-title":"J. Phys. Act. Health"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1097\/PEP.0000000000000272","article-title":"Immediate effect of positioning devices on infant leg movement characteristics","volume":"28","author":"Jiang","year":"2016","journal-title":"Pediatr. Phys. Ther."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/13\/2886\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:02:24Z","timestamp":1760187744000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/13\/2886"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,6,29]]},"references-count":10,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2019,7]]}},"alternative-id":["s19132886"],"URL":"https:\/\/doi.org\/10.3390\/s19132886","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,6,29]]}}}