{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T22:50:07Z","timestamp":1781909407566,"version":"3.54.5"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2024,2,8]],"date-time":"2024-02-08T00:00:00Z","timestamp":1707350400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Universit\u00e9 Laval Research Chair in Cerebral Palsy","award":["#0021"],"award-info":[{"award-number":["#0021"]}]},{"name":"Universit\u00e9 Laval Research Chair in Cerebral Palsy","award":["#251649"],"award-info":[{"award-number":["#251649"]}]},{"name":"Fonds de recherche du Qu\u00e9bec\u2013Sant\u00e9","award":["#0021"],"award-info":[{"award-number":["#0021"]}]},{"name":"Fonds de recherche du Qu\u00e9bec\u2013Sant\u00e9","award":["#251649"],"award-info":[{"award-number":["#251649"]}]},{"name":"Canadian Institutes of Health Research","award":["#0021"],"award-info":[{"award-number":["#0021"]}]},{"name":"Canadian Institutes of Health Research","award":["#251649"],"award-info":[{"award-number":["#251649"]}]},{"name":"Canada Research Chair in Pain and Sensorimotor Rehabilitation","award":["#0021"],"award-info":[{"award-number":["#0021"]}]},{"name":"Canada Research Chair in Pain and Sensorimotor Rehabilitation","award":["#251649"],"award-info":[{"award-number":["#251649"]}]},{"name":"Research Scholar awards from FRQ-S (J2)","award":["#0021"],"award-info":[{"award-number":["#0021"]}]},{"name":"Research Scholar awards from FRQ-S (J2)","award":["#251649"],"award-info":[{"award-number":["#251649"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Various accelerometry protocols have been used to quantify upper extremity (UE) activity, encompassing diverse epoch lengths and thresholding methods. However, there is no consensus on the most effective approach. The aim of this study was to delineate the optimal parameters for analyzing accelerometry data to quantify UE use in individuals with unilateral cerebral palsy (CP). Methods: A group of adults with CP (n = 15) participated in six activities of daily living, while a group of children with CP (n = 14) underwent the Assisting Hand Assessment. Both groups performed the activities while wearing ActiGraph GT9X-BT devices on each wrist, with concurrent video recording. Use ratio (UR) derived from accelerometry and video analysis and accelerometer data were compared for different epoch lengths (1, 1.5, and 2 s) and activity count (AC) thresholds (between 2 and 150). Results: In adults, results are comparable across epoch lengths, with the best AC thresholds being \u2265 100. In children, results are similar across epoch lengths of 1 and 1.5 (optimal AC threshold = 50), while the optimal threshold is higher with an epoch length of 2 (AC = 75). Conclusions: The combination of epoch length and AC thresholds should be chosen carefully as both influence the validity of the quantification of UE use.<\/jats:p>","DOI":"10.3390\/s24041100","type":"journal-article","created":{"date-parts":[[2024,2,8]],"date-time":"2024-02-08T03:36:17Z","timestamp":1707363377000},"page":"1100","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Optimizing Epoch Length and Activity Count Threshold Parameters in Accelerometry: Enhancing Upper Extremity Use Quantification in Cerebral Palsy"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0101-0118","authenticated-orcid":false,"given":"Isabelle","family":"Poitras","sequence":"first","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"School of Rehabilitation Sciences, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7264-5508","authenticated-orcid":false,"given":"L\u00e9andre","family":"Gagn\u00e9-Pelletier","sequence":"additional","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"School of Rehabilitation Sciences, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jade","family":"Clou\u00e2tre","sequence":"additional","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"Department of Mechanical Engineering, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"V\u00e9ronique H.","family":"Flamand","sequence":"additional","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"School of Rehabilitation Sciences, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6766-3368","authenticated-orcid":false,"given":"Alexandre","family":"Campeau-Lecours","sequence":"additional","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"Department of Mechanical Engineering, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2037-6916","authenticated-orcid":false,"given":"Catherine","family":"Mercier","sequence":"additional","affiliation":[{"name":"Centre for Interdisciplinary Research in Rehabilitation and Social Integration (Cirris), Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et Services Sociaux de la Capitale-Nationale, Quebec City, QC G1M 2S8, Canada"},{"name":"School of Rehabilitation Sciences, Laval University, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,2,8]]},"reference":[{"key":"ref_1","unstructured":"Bailey, R.R. (2015). Assessment of Real-World Upper Limb Activity in Adults with Chronic Stroke, Washington University in St. Louis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1177\/1545968311408918","article-title":"Disparity between functional recovery and daily use of the upper and lower extremities during subacute stroke rehabilitation","volume":"26","author":"Rand","year":"2012","journal-title":"Neurorehabil. Neural Repair"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e192970","DOI":"10.1001\/jamanetworkopen.2019.2970","article-title":"Detection of Pediatric Upper Extremity Motor Activity and Deficits With Accelerometry","volume":"2","author":"Hoyt","year":"2019","journal-title":"JAMA Netw. Open"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6119","DOI":"10.1080\/09638288.2021.1957027","article-title":"The use of wearable sensors to assess and treat the upper extremity after stroke: A scoping review","volume":"44","author":"Kim","year":"2022","journal-title":"Disabil. Rehabil."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1913","DOI":"10.1016\/j.apmr.2017.12.025","article-title":"Comparison of Self-Report Versus Sensor-Based Methods for Measuring the Amount of Upper Limb Activity Outside the Clinic","volume":"99","author":"Waddell","year":"2018","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1189","DOI":"10.1212\/01.wnl.0000238164.90657.c2","article-title":"The Motor Activity Log-28: Assessing daily use of the hemiparetic arm after stroke","volume":"67","author":"Uswatte","year":"2006","journal-title":"Neurology"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Simpson, L.A., Eng, J.J., Backman, C.L., and Miller, W.C. (2013). Rating of Everyday Arm-Use in the Community and Home (REACH) Scale for Capturing Affected Arm-Use after Stroke: Development, Reliability, and Validity. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0083405"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Stone, A.A., Bachrach, C.A., Jobe, J.B., Kurtzman, H.S., and Cain, V.S. (1999). The Science of Self-Report: Implications for Research and Practice, Psychology Press.","DOI":"10.4324\/9781410601261"},{"key":"ref_9","first-page":"80","article-title":"Post-stroke cognitive impairment: Epidemiology, mechanisms and management","volume":"2","author":"Sun","year":"2014","journal-title":"Ann. Transl. Med."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1111\/dmcn.14463","article-title":"Cognitive functioning in children with cerebral palsy","volume":"62","author":"Stadskleiv","year":"2020","journal-title":"Dev. Med. Child Neurol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1340","DOI":"10.1016\/j.apmr.2006.06.006","article-title":"Validity of accelerometry for monitoring real-world arm activity in patients with subacute stroke: Evidence from the extremity constraint-induced therapy evaluation trial","volume":"87","author":"Uswatte","year":"2006","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Bailey, R.R., Klaesner, J.W., and Lang, C.E. (2014). An Accelerometry-Based Methodology for Assessment of Real-World Bilateral Upper Extremity Activity. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0103135"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Poitras, I., Clou\u00e2tre, J., Campeau-Lecours, A., and Mercier, C. (2022). Accelerometry-Based Metrics to Evaluate the Relative Use of the More Affected Arm during Daily Activities in Adults Living with Cerebral Palsy. Sensors, 22.","DOI":"10.3390\/s22031022"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Heye, A.-L., Kersting, C., Kneer, M., and Barzel, A. (2022). Suitability of accelerometry as an objective measure for upper extremity use in stroke patients. BMC Neurol., 22.","DOI":"10.1186\/s12883-022-02743-w"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1017\/BrImp.2015.21","article-title":"Exploring the Role of Accelerometers in the Measurement of Real World Upper-Limb Use After Stroke","volume":"17","author":"Hayward","year":"2016","journal-title":"Brain Impair."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1161\/01.STR.31.3.662","article-title":"Objective measurement of functional upper-extremity movement using accelerometer recordings transformed with a threshold filter","volume":"31","author":"Uswatte","year":"2000","journal-title":"Stroke"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1179\/1074935714Z.0000000040","article-title":"Real-world affected upper limb activity in chronic stroke: An examination of potential modifying factors","volume":"22","author":"Bailey","year":"2015","journal-title":"Top. Stroke Rehabil."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1080\/10749357.2019.1690796","article-title":"Upper limb use differs among people with varied upper limb impairment levels early post-stroke: A single-site, cross-sectional, observational study","volume":"27","author":"Chin","year":"2020","journal-title":"Top. Stroke Rehabil."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Barth, J., Geed, S., Mitchell, A., Lum, P.S., Edwards, D.F., and Dromerick, A.W. (2020). Characterizing upper extremity motor behavior in the first week after stroke. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0221668"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1097\/NPT.0000000000000085","article-title":"Validity of body-worn sensor acceleration metrics to index upper extremity function in hemiparetic stroke","volume":"39","author":"Urbin","year":"2015","journal-title":"J. Neurol. Phys. Ther. JNPT"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Essers, B., Biering Lundquist, C., Verheyden, G., and Brunner, I.C. (2022). Determinants of Different Aspects of Upper-Limb Activity after Stroke. Sensors, 22.","DOI":"10.3390\/s22062273"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1957","DOI":"10.1016\/j.apmr.2012.05.011","article-title":"Relationship between arm usage and instrumental activities of daily living after unilateral stroke","volume":"93","author":"Haaland","year":"2012","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1097\/NPT.0b013e31806748bd","article-title":"Upper extremity use in people with hemiparesis in the first few weeks after stroke","volume":"31","author":"Lang","year":"2007","journal-title":"J. Neurol. Phys. Ther."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"952757","DOI":"10.3389\/fphys.2022.952757","article-title":"Classification of functional and non-functional arm use by inertial measurement units in individuals with upper limb impairment after stroke","volume":"13","author":"Pohl","year":"2022","journal-title":"Front. Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1177\/1545968309345269","article-title":"Greater activation of secondary motor areas is related to less arm use after stroke","volume":"24","author":"Kokotilo","year":"2010","journal-title":"Neurorehabil. Neural Repair"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1016\/j.nicl.2017.01.009","article-title":"Hemispheric asymmetry in myelin after stroke is related to motor impairment and function","volume":"14","author":"Lakhani","year":"2017","journal-title":"NeuroImage Clin."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1177\/0269215517712042","article-title":"A study of predictive validity, responsiveness, and minimal clinically important difference of arm accelerometer in real-world activity of patients with chronic stroke","volume":"32","author":"Chen","year":"2018","journal-title":"Clin. Rehabil."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1519\/JPT.0000000000000067","article-title":"Accelerometer-Based Monitoring of Upper Limb Movement in Older Adults With Acute and Subacute Stroke","volume":"39","author":"Narai","year":"2016","journal-title":"J. Geriatr. Phys. Ther."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"jrm00210","DOI":"10.2340\/16501977-2838","article-title":"Arm impairment and walking speed explain real-life activity of the affected arm and leg after stroke","volume":"53","author":"Andersson","year":"2021","journal-title":"J. Rehabil. Med."},{"key":"ref_30","first-page":"55673","article-title":"A Method for Quantifying Upper Limb Performance in Daily Life Using Accelerometers","volume":"122","author":"Lang","year":"2017","journal-title":"J. Vis. Exp. JoVE"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Ayabe, M., Kumahara, H., Morimura, K., and Tanaka, H. (2013). Epoch length and the physical activity bout analysis: An accelerometry research issue. BMC Res. Notes, 6.","DOI":"10.1186\/1756-0500-6-20"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"S531","DOI":"10.1249\/01.mss.0000185657.86065.98","article-title":"Conducting accelerometer-based activity assessments in field-based research","volume":"37","author":"Trost","year":"2005","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_33","first-page":"311","article-title":"An objective and standardized test of hand function","volume":"50","author":"Jebsen","year":"1969","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"88","DOI":"10.3109\/01942638.2015.1040571","article-title":"Establishing Australian Norms for the Jebsen Taylor Test of Hand Function in Typically Developing Children Aged Five to 10 Years: A Pilot Study","volume":"36","author":"Beagley","year":"2016","journal-title":"Phys. Occup. Ther. Pediatr."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1303","DOI":"10.1111\/dmcn.13168","article-title":"Development of the Assisting Hand Assessment for adolescents (Ad-AHA) and validation of the AHA from 18 months to 18 years","volume":"58","author":"Louwers","year":"2016","journal-title":"Dev. Med. Child Neurol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Poitras, I., Clou\u00e2tre, J., Bouyer, L.J., Routhier, F., Mercier, C., and Campeau-Lecours, A. (2020). Development and Validation of Open-Source Activity Intensity Count and Activity Intensity Classification Algorithms from Raw Acceleration Signals of Wearable Sensors. Sensors, 20.","DOI":"10.3390\/s20236767"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.jcm.2016.02.012","article-title":"A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research","volume":"15","author":"Koo","year":"2016","journal-title":"J. Chiropr. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1213","DOI":"10.1682\/JRRD.2012.12.0222","article-title":"Upper-limb activity in adults: Referent values using accelerometry","volume":"50","author":"Bailey","year":"2013","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2410","DOI":"10.1016\/j.apmr.2014.05.025","article-title":"Investigating measures of intensity during a structured upper limb exercise program in stroke rehabilitation: An exploratory study","volume":"95","author":"Connell","year":"2014","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"733","DOI":"10.1177\/1545968314521008","article-title":"Eliciting upper extremity purposeful movements using video games: A comparison with traditional therapy for stroke rehabilitation","volume":"28","author":"Rand","year":"2014","journal-title":"Neurorehabil. Neural Repair"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1080\/09638280500158422","article-title":"The epidemiology of cerebral palsy: Incidence, impairments and risk factors","volume":"28","author":"Odding","year":"2006","journal-title":"Disabil. Rehabil."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"814","DOI":"10.1097\/PHM.0b013e31825f13a3","article-title":"Spasticity After Stroke: An Overview of Prevalence, Test Instruments, and Treatments","volume":"91","author":"Sommerfeld","year":"2012","journal-title":"Am. J. Phys. Med. Rehabil."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Regterschot, G.R.H., Selles, R.W., Ribbers, G.M., and Bussmann, J.B.J. (2021). Whole-Body Movements Increase Arm Use Outcomes of Wrist-Worn Accelerometers in Stroke Patients. Sensors, 21.","DOI":"10.3390\/s21134353"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Gagn\u00e9-Pelletier, L., Poitras, I., Flamand, V.H., and Mercier, C. (2023). Reliability of an observation-based scoring grid to assess bimanual performance during unstandardized tasks in adults living with cerebral palsy. Disabil. Rehabil., 1\u20136.","DOI":"10.1080\/09638288.2023.2254700"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1498","DOI":"10.1016\/j.apmr.2005.01.010","article-title":"Ambulatory monitoring of arm movement using accelerometry: An objective measure of upper-extremity rehabilitation in persons with chronic stroke","volume":"86","author":"Uswatte","year":"2005","journal-title":"Arch. Phys. Med. Rehabil."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/4\/1100\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T13:56:54Z","timestamp":1760104614000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/4\/1100"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,2,8]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2024,2]]}},"alternative-id":["s24041100"],"URL":"https:\/\/doi.org\/10.3390\/s24041100","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,2,8]]}}}