{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,11]],"date-time":"2026-07-11T10:34:33Z","timestamp":1783766073219,"version":"3.55.0"},"reference-count":46,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,1,23]],"date-time":"2022-01-23T00:00:00Z","timestamp":1642896000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the National Key R&amp;D Program of China","award":["2019YFF0301803"],"award-info":[{"award-number":["2019YFF0301803"]}]},{"name":"the Fundamental Research Funds for the Central Universities of China","award":["2021TD008"],"award-info":[{"award-number":["2021TD008"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The purpose of this research was to determine if the commercially available Perception Neuron motion capture system was valid and reliable in clinically relevant lower limb functional tasks. Twenty healthy participants performed two sessions on different days: gait, squat, single-leg squat, side lunge, forward lunge, and counter-movement jump. Seven IMUs and an OptiTrack system were used to record the three-dimensional joint kinematics of the lower extremity. To evaluate the performance, the multiple correlation coefficient (CMC) and the root mean square error (RMSE) of the waveforms as well as the difference and intraclass correlation coefficient (ICC) of discrete parameters were calculated. In all tasks, the CMC revealed fair to excellent waveform similarity (0.47\u20130.99) and the RMSE was between 3.57\u00b0 and 13.14\u00b0. The difference between discrete parameters was lower than 14.54\u00b0. The repeatability analysis of waveforms showed that the CMC was between 0.54 and 0.95 and the RMSE was less than 5\u00b0 in the frontal and transverse planes. The ICC of all joint angles in the IMU was general to excellent (0.57\u20131). Our findings showed that the IMU system might be utilized to evaluate lower extremity 3D joint kinematics in functional motions.<\/jats:p>","DOI":"10.3390\/s22030863","type":"journal-article","created":{"date-parts":[[2022,1,23]],"date-time":"2022-01-23T20:36:27Z","timestamp":1642970187000},"page":"863","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["Reliability and Validity of an Inertial Measurement System to Quantify Lower Extremity Joint Angle in Functional Movements"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6351-6835","authenticated-orcid":false,"given":"Zhenyu","family":"Shuai","sequence":"first","affiliation":[{"name":"Sports Coaching College, Beijing Sport University, 48 Xinxi Road, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anqi","family":"Dong","sequence":"additional","affiliation":[{"name":"AI Sports Engineering Lab, School of Sports Engineering, Beijing Sport University, 48 Xinxi Road, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haoyang","family":"Liu","sequence":"additional","affiliation":[{"name":"AI Sports Engineering Lab, School of Sports Engineering, Beijing Sport University, 48 Xinxi Road, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1755-9631","authenticated-orcid":false,"given":"Yixiong","family":"Cui","sequence":"additional","affiliation":[{"name":"AI Sports Engineering Lab, School of Sports Engineering, Beijing Sport University, 48 Xinxi Road, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,23]]},"reference":[{"key":"ref_1","first-page":"396","article-title":"Functional Movement Screening: The Use of Fundamental Movements as an Assessment of Function\u2014Part 1","volume":"9","author":"Cook","year":"2014","journal-title":"Int. J. Sports Phys. Ther."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2736559","DOI":"10.1109\/JTEHM.2017.2736559","article-title":"Automated Assessment of Dynamic Knee Valgus and Risk of Knee Injury during the Single Leg Squat","volume":"5","author":"Kianifar","year":"2017","journal-title":"IEEE J. Transl. Eng. Health Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1080\/03093640600983949","article-title":"Clinical Applications of Sensors for Human Posture and Movement Analysis: A Review","volume":"31","author":"Wong","year":"2007","journal-title":"Prosthet. Orthot. Int."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1016\/j.gaitpost.2015.01.019","article-title":"Motion Analysis of Patients after Knee Arthroplasty during Activities of Daily Living\u2014A Systematic Review","volume":"41","author":"Komnik","year":"2015","journal-title":"Gait Posture"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"11556","DOI":"10.3390\/s101211556","article-title":"The Use of Wearable Inertial Motion Sensors in Human Lower Limb Biomechanics Studies: A Systematic Review","volume":"10","author":"Fong","year":"2010","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.gaitpost.2016.11.008","article-title":"25 Years of Lower Limb Joint Kinematics by Using Inertial and Magnetic Sensors: A Review of Methodological Approaches","volume":"51","author":"Picerno","year":"2017","journal-title":"Gait Posture"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s11517-009-0544-y","article-title":"First in Vivo Assessment of \u201cOutwalk\u201d: A Novel Protocol for Clinical Gait Analysis Based on Inertial and Magnetic Sensors","volume":"48","author":"Ferrari","year":"2010","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1016\/j.gaitpost.2008.04.003","article-title":"Joint Kinematics Estimate Using Wearable Inertial and Magnetic Sensing Modules","volume":"28","author":"Picerno","year":"2008","journal-title":"Gait Posture"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2330","DOI":"10.1016\/j.jbiomech.2009.06.025","article-title":"Functional Calibration Procedure for 3d Knee Joint Angle Description Using Inertial Sensors","volume":"42","author":"Favre","year":"2009","journal-title":"J. Biomech."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Panero, E., Digo, E., Agostini, V., and Gastaldi, L. (2018, January 11\u201313). Comparison of Different Motion Capture Setups for Gait Analysis: Validation of Spatio-Temporal Parameters Estimation. Proceedings of the 2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA), Rome, Italy.","DOI":"10.1109\/MeMeA.2018.8438653"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"N63","DOI":"10.1088\/0967-3334\/34\/8\/N63","article-title":"Concurrent Validation of Xsens Mvn Measurement of Lower Limb Joint Angular Kinematics","volume":"34","author":"Zhang","year":"2013","journal-title":"Physiol. Meas."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.gaitpost.2017.04.013","article-title":"Validity and Repeatability of Inertial Measurement Units for Measuring Gait Parameters","volume":"55","author":"Washabaugh","year":"2017","journal-title":"Gait Posture"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1186\/s12984-020-00685-3","article-title":"Validity and Reliability of Wearable Inertial Sensors in Healthy Adult Walking: A Systematic Review and Meta-Analysis","volume":"17","author":"Kobsar","year":"2020","journal-title":"J. Neuroeng. Rehabil."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.medengphy.2015.11.009","article-title":"Validity of an Inertial Measurement Unit to Assess Pelvic Orientation Angles during Gait, Sit-Stand Transfers and Step-up Transfers: Comparison with an Optoelectronic Motion Capture System","volume":"38","author":"Bolink","year":"2016","journal-title":"Med. Eng. Phys."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Tak, I., Wiertz, W.P., Barendrecht, M., and Langhout, R. (2020). Validity of a New 3-D Motion Analysis Tool for the Assessment of Knee, Hip and Spine Joint Angles During the Single Leg Squat. Sensors, 20.","DOI":"10.3390\/s20164539"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.measurement.2016.01.007","article-title":"Concurrent Validation of Magnetic and Inertial Measurement Units in Estimating Upper Body Posture During Gait","volume":"82","author":"Kang","year":"2016","journal-title":"Measurement"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1007\/s11517-016-1537-2","article-title":"Validation of Inertial Measurement Units with an Optoelectronic System for Whole-Body Motion Analysis","volume":"55","author":"Mecheri","year":"2017","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Al-Amri, M., Nicholas, K., Button, K., Sparkes, V., Sheeran, L., and Davies, J.L. (2018). Inertial Measurement Units for Clinical Movement Analysis: Reliability and Concurrent Validity. Sensors, 18.","DOI":"10.3390\/s18030719"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1111\/sms.13851","article-title":"3d Trunk Orientation Measured Using Inertial Measurement Units During Anatomical and Dynamic Sports Motions","volume":"31","author":"Brouwer","year":"2021","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_20","unstructured":"NOITOM (2021, August 10). Axis Neuron Userguide. Available online: https:\/\/shopcdn.noitom.com.cn\/article\/36.html."},{"key":"ref_21","unstructured":"China Global Television Network (2021, August 21). Available online: https:\/\/news.cgtn.com\/news\/3067544d31494464776c6d636a4e6e62684a4856\/share_p.html."},{"key":"ref_22","unstructured":"Cision Prweb (2021, August 20). Available online: https:\/\/www.prweb.com\/releases\/short_film_twenty_one_points_features_vfx_magic_created_with_perception_neuron_motion_capture_that_makes_high_quality_3d_animation_possible_for_directors_at_any_budget\/prweb15858480.htm."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Kim, H.S., Hong, N., Kim, M., Yoon, S.G., Yu, H.W., Kong, H.J., Kim, S.J., Chai, Y.J., Choi, H.J., and Choi, J.Y. (2019). Application of a Perception Neuron(\u00ae) System in Simulation-Based Surgical Training. J. Clin. Med., 8.","DOI":"10.3390\/jcm8010124"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"107024","DOI":"10.1016\/j.measurement.2019.107024","article-title":"Validity of the Perception Neuron Inertial Motion Capture System for Upper Body Motion Analysis","volume":"149","author":"Sers","year":"2020","journal-title":"Measurement"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1186\/s12984-020-00694-2","article-title":"Functional Movement Assessment by Means of Inertial Sensor Technology to Discriminate between Movement Behaviour of Healthy Controls and Persons with Knee Osteoarthritis","volume":"17","author":"Wesseling","year":"2020","journal-title":"J. Neuroeng. Rehabil."},{"key":"ref_26","unstructured":"(2021, August 07). Point, Natural. Optitrack System-Optitrack Documentation Wiki (Motive Version 2.1). Available online: https:\/\/v21.wiki.optitrack.com\/index.php?title=OptiTrack_Documentation_Wiki."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1002\/jor.1100080310","article-title":"Measurement of Lower Extremity Kinematics during Level Walking","volume":"8","author":"Kadaba","year":"1990","journal-title":"J. Orthop. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.ptsp.2013.05.001","article-title":"The Reliability and Validity of the Measurement of Lateral Trunk Motion in Two-Dimensional Video Analysis during Unipodal Functional Screening Tests in Elite Female Athletes","volume":"15","author":"Dingenen","year":"2013","journal-title":"Phys. Ther. Sport"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/j.physio.2013.03.001","article-title":"Affordable Clinical Gait Analysis: An Assessment of the Marker Tracking Accuracy of a New Low-Cost Optical 3d Motion Analysis System","volume":"99","author":"Carse","year":"2013","journal-title":"Physiotherapy"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1016\/j.gaitpost.2010.02.009","article-title":"A New Formulation of the Coefficient of Multiple Correlation to Assess the Similarity of Waveforms Measured Synchronously by Different Motion Analysis Protocols","volume":"31","author":"Ferrari","year":"2010","journal-title":"Gait Posture"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1037\/0033-2909.86.2.420","article-title":"Intraclass Correlations: Uses in Assessing Rater Reliability","volume":"86","author":"Shrout","year":"1979","journal-title":"Psychol. Bull."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2486","DOI":"10.1016\/j.jbiomech.2009.07.016","article-title":"Gait Posture Estimation Using Wearable Acceleration and Gyro Sensor","volume":"42","author":"Takeda","year":"2009","journal-title":"J. Biomech."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1007\/s11517-012-1006-5","article-title":"Gait Analysis in Children with Cerebral Palsy Via Inertial and Magnetic Sensors","volume":"51","author":"Ferrari","year":"2013","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Cloete, T., and Scheffer, C. (2008, January 20\u201325). Benchmarking of a Full-Body Inertial Motion Capture System for Clinical Gait Analysis. Proceedings of the 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Vancouver, BC, Canada.","DOI":"10.1109\/IEMBS.2008.4650232"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2678","DOI":"10.1016\/j.jbiomech.2009.08.004","article-title":"Inertial Sensor-Based Knee Flexion\/Extension Angle Estimation","volume":"42","author":"Cooper","year":"2009","journal-title":"J. Biomech."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1016\/j.jbiomech.2007.12.003","article-title":"Ambulatory Measurement of 3d Knee Joint Angle","volume":"41","author":"Favre","year":"2008","journal-title":"J. Biomech."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Teufl, W., Miezal, M., Taetz, B., Fr\u00f6hlich, M., and Bleser, G. (2019). Validity of Inertial Sensor Based 3d Joint Kinematics of Static and Dynamic Sport and Physiotherapy Specific Movements. PLoS ONE, 14.","DOI":"10.1371\/journal.pone.0213064"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2838","DOI":"10.1016\/j.jbiomech.2011.09.006","article-title":"Assessment of Anatomical Frame Variation Effect on Joint Angles: A Linear Perturbation Approach","volume":"44","author":"Brennan","year":"2011","journal-title":"J. Biomech."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1007\/BF02513282","article-title":"Pelvis and Lower Limb Anatomical Landmark Calibration Precision and Its Propagation to Bone Geometry and Joint Angles","volume":"37","author":"Cappozzo","year":"1999","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"6891","DOI":"10.3390\/s140406891","article-title":"Imu-Based Joint Angle Measurement for Gait Analysis","volume":"14","author":"Seel","year":"2014","journal-title":"Sensors"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Teufl, W., Miezal, M., Taetz, B., Fr\u00f6hlich, M., and Bleser, G. (2018). Validity, Test-Retest Reliability and Long-Term Stability of Magnetometer Free Inertial Sensor Based 3d Joint Kinematics. Sensors, 18.","DOI":"10.3390\/s18071980"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.gaitpost.2004.05.002","article-title":"Human Movement Analysis Using Stereophotogrammetry. Part 3. Soft Tissue Artifact Assessment and Compensation","volume":"21","author":"Leardini","year":"2005","journal-title":"Gait Posture"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.gaitpost.2017.03.033","article-title":"Soft Tissue Artifact Causes Significant Errors in the Calculation of Joint Angles and Range of Motion at the Hip","volume":"55","author":"Fiorentino","year":"2017","journal-title":"Gait Posture"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.medengphy.2018.12.021","article-title":"Musculoskeletal Model-Based Inverse Dynamic Analysis under Ambulatory Conditions Using Inertial Motion Capture","volume":"65","author":"Karatsidis","year":"2019","journal-title":"Med. Eng. Phys."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/j.gaitpost.2008.09.003","article-title":"The Reliability of Three-Dimensional Kinematic Gait Measurements: A Systematic Review","volume":"29","author":"McGinley","year":"2009","journal-title":"Gait Posture"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Poitras, I., Dupuis, F., Bielmann, M., Campeau-Lecours, A., Mercier, C., Bouyer, L.J., and Roy, J.S. (2019). Validity and Reliability of Wearable Sensors for Joint Angle Estimation: A Systematic Review. Sensors, 19.","DOI":"10.3390\/s19071555"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/3\/863\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:06:16Z","timestamp":1760133976000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/3\/863"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,23]]},"references-count":46,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2022,2]]}},"alternative-id":["s22030863"],"URL":"https:\/\/doi.org\/10.3390\/s22030863","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,23]]}}}