{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T06:50:26Z","timestamp":1778309426468,"version":"3.51.4"},"reference-count":51,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2019,6,28]],"date-time":"2019-06-28T00:00:00Z","timestamp":1561680000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["NRF-2017R1C1B2006811"],"award-info":[{"award-number":["NRF-2017R1C1B2006811"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]},{"name":"High Risk High Return Project of KAIST","award":["N1017003"],"award-info":[{"award-number":["N1017003"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Older people face difficulty engaging in conventional rehabilitation exercises for improving physical functions over a long time period due to the passive nature of the conventional exercise, inconvenience, and cost. This study aims to develop and validate a dynamic time warping (DTW) based algorithm for assessing Kinect-enabled home-based physical rehabilitation exercises, in order to support auto-coaching in a virtual gaming environment. A DTW-based algorithm was first applied to compute motion similarity between two time series from an individual user and a virtual coach. We chose eight bone vectors of the human skeleton and body orientation as the input features and proposed a simple but innovative method to further convert the DTW distance to a meaningful performance score in terms of the percentage (0\u2013100%), without training data and experience of experts. The effectiveness of the proposed algorithm was validated through a follow-up experiment with 21 subjects when playing a Tai Chi exergame. Results showed that the algorithm scores had a strong positive linear relationship (r = 0.86) with experts\u2019 ratings and the calibrated algorithm scores were comparable to the gold standard. These findings suggested that the DTW-based algorithm could be effectively used for automatic performance evaluation of an individual when performing home-based rehabilitation exercises.<\/jats:p>","DOI":"10.3390\/s19132882","type":"journal-article","created":{"date-parts":[[2019,6,28]],"date-time":"2019-06-28T11:20:26Z","timestamp":1561720826000},"page":"2882","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":60,"title":["A Dynamic Time Warping Based Algorithm to Evaluate Kinect-Enabled Home-Based Physical Rehabilitation Exercises for Older People"],"prefix":"10.3390","volume":"19","author":[{"given":"Xiaoqun","family":"Yu","sequence":"first","affiliation":[{"name":"Department of Industrial and Systems Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1549-515X","authenticated-orcid":false,"given":"Shuping","family":"Xiong","sequence":"additional","affiliation":[{"name":"Department of Industrial and Systems Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,6,28]]},"reference":[{"key":"ref_1","unstructured":"(2019, March 09). World Health Organization Ageing and Health. Available online: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/ageing-and-health."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1097\/PHM.0b013e3181f703ef","article-title":"Frail institutionalized older persons: A comprehensive review on physical exercise, physical fitness, activities of daily living, and quality-of-life","volume":"90","author":"Scherder","year":"2011","journal-title":"Am. J. Phys. Med. Rehabil."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1080\/13607861003713232","article-title":"Is exercise effective in promoting mental well-being in older age? A systematic review","volume":"14","author":"Windle","year":"2010","journal-title":"Aging Ment. Health"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1159\/000443611","article-title":"Long-term effects of individually tailored physical training and activity on physical function, well-being and cognition in Scandinavian nursing home residents: A randomized controlled trial","volume":"62","author":"Helbostad","year":"2016","journal-title":"Gerontology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2565","DOI":"10.1001\/archinte.163.21.2565","article-title":"Physical activity and functional status in community-dwelling older women: A 14-year prospective study","volume":"163","author":"Brach","year":"2003","journal-title":"Arch. Intern. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.archger.2009.12.001","article-title":"Effects of a physical training and nutritional intervention program in frail elderly people regarding habitual physical activity level and activities of daily living\u2014A randomized controlled pilot study","volume":"51","author":"Rydwik","year":"2010","journal-title":"Arch. Gerontol. Geriatr."},{"key":"ref_7","unstructured":"Organization, W.H. (2007). A guide for population-based approaches to increasing levels of physical activity. Implementation of the WHO Global Strategy on Diet, Physical Activity and Health, World Health Organization."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1177\/0733464810385815","article-title":"Attitudes and beliefs predicting Taiwanese older adults\u2019 intentions to attend strength and balance training programs","volume":"31","author":"Lin","year":"2012","journal-title":"J. Appl. Gerontol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1016\/j.apergo.2016.10.013","article-title":"Exergame technology and interactive interventions for elderly fall prevention: A systematic literature review","volume":"65","author":"Choi","year":"2017","journal-title":"Appl. Ergon."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"650","DOI":"10.1093\/geront\/46.5.650","article-title":"Older people\u2019s views of falls-prevention interventions in six European countries","volume":"46","author":"Yardley","year":"2006","journal-title":"Gerontologist"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1007\/BF02898014","article-title":"Effects of physical exercise on fall risk factors in elderly at home in intervention trial","volume":"11","author":"Kobayashi","year":"2006","journal-title":"Environ. Health Prev. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1821","DOI":"10.1111\/j.1532-5415.2008.01931.x","article-title":"Otago home-based strength and balance retraining improves executive functioning in older fallers: A randomized controlled trial","volume":"56","author":"Donaldson","year":"2008","journal-title":"J. Am. Geriatr. Soc."},{"key":"ref_13","unstructured":"Uzor, S., and Baillie, L. (May, January 26). Investigating the long-term use of exergames in the home with elderly fallers. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, Toronto, ON, Canada."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Arlati, S., Colombo, V., Spoladore, D., Greci, L., Pedroli, E., Serino, S., Cipresso, P., Goulene, K., Stramba-Badiale, M., and Riva, G. (2019). A Social Virtual Reality-Based Application for the Physical and Cognitive Training of the Elderly at Home. Sensors, 19.","DOI":"10.3390\/s19020261"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Fortino, G., and Gravina, R. (2014). A cloud-assisted wearable system for physical rehabilitation. ICTs for Improving Patients Rehabilitation Research Techniques, Springer.","DOI":"10.1007\/978-3-662-48645-0_15"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1109\/JBHI.2015.2391671","article-title":"Design and evaluation of an interactive exercise coaching system for older adults: Lessons learned","volume":"20","author":"Ofli","year":"2016","journal-title":"IEEE J. Biomed. Health Inform."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Lin, T.Y., Hsieh, C.H., and Lee, J.D. (2013, January 23\u201325). A kinect-based system for physical rehabilitation: Utilizing Tai Chi exercises to improve movement disorders in patients with balance ability. Proceedings of the Asia Modelling Symposium 2013: 7th Asia International Conference on Mathematical Modelling and Computer Simulation, Hong Kong, China.","DOI":"10.1109\/AMS.2013.29"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Muangmoon, O.-O., Sureephong, P., and Tabia, K. (2017). Dance Training Tool Using Kinect-Based Skeleton Tracking and Evaluating Dancer\u2019s Performance. International Conference on Industrial, Engineering and other Applications of Applied Intelligent Systems, Springer.","DOI":"10.1007\/978-3-319-60045-1_4"},{"key":"ref_19","unstructured":"Alexiadis, D.S., Kelly, P., Daras, P., O\u2019Connor, N.E., Boubekeur, T., and Moussa, M.B. (December, January 28). Evaluating a dancer\u2019s performance using kinect-based skeleton tracking. Proceedings of the 19th ACM International Conference on Multimedia, Scottsdale, AZ, USA."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Ren, W., Pu, F., Fan, X., Li, S., Sun, L., Li, D., Wang, Y., and Fan, Y. (2016). Kinect-Based Skeleton-Matching Feedback for Motor Rehabilitation: Transient Performance Effect of Shoulder training. J. Mech. Med. Biol., 16.","DOI":"10.1142\/S0219519416500378"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Capecci, M., Ceravolo, M.G., Ferracuti, F., Iarlori, S., Kyrki, V., Longhi, S., Romeo, L., and Verdini, F. (2016, January 24\u201327). Physical rehabilitation exercises assessment based on hidden semi-markov model by kinect v2. Proceedings of the 2016 IEEE-EMBS International Conference on Biomedical and Health Informatics (BHI), Las Vegas, NV, USA.","DOI":"10.1109\/BHI.2016.7455883"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Rybarczyk, Y., Deters, J.K., Gonzalo, A.A., Esparza, D., Gonzalez, M., Villarreal, S., and Nunes, I.L. (2017). Recognition of physiotherapeutic exercises through DTW and low-cost vision-based motion capture. International Conference on Applied Human Factors and Ergonomics, Springer.","DOI":"10.1007\/978-3-319-60366-7_33"},{"key":"ref_23","unstructured":"M\u00fcller, M., and R\u00f6der, T. (2006, January 2\u20134). Motion templates for automatic classification and retrieval of motion capture data. Proceedings of the 2006 ACM SIGGRAPH\/Eurographics Symposium on Computer Animation, Vienna, Austria."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Saraee, E., Singh, S., Hendron, K., Zheng, M., Joshi, A., Ellis, T., and Betke, M. (2017, January 21\u201323). ExerciseCheck: Remote monitoring and evaluation platform for home based physical therapy. Proceedings of the 10th International Conference on PErvasive Technologies Related to Assistive Environments, Rhodes, Greece.","DOI":"10.1145\/3056540.3064958"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.imu.2018.10.002","article-title":"Visual feedback framework for rehabilitation of stroke patients","volume":"13","author":"Semblantes","year":"2018","journal-title":"Inform. Med. Unlocked"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Saenz-de-Urturi, Z., and Garcia-Zapirain Soto, B. (2016). Kinect-based virtual game for the elderly that detects incorrect body postures in real time. Sensors, 16.","DOI":"10.3390\/s16050704"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1016\/j.asoc.2014.04.020","article-title":"Kinect-enabled home-based rehabilitation system using Dynamic Time Warping and fuzzy logic","volume":"22","author":"Su","year":"2014","journal-title":"Appl. Soft Comput."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1929","DOI":"10.1007\/s00779-014-0799-7","article-title":"Performance monitoring and evaluation in dance teaching with mobile sensing technology","volume":"18","author":"Wei","year":"2014","journal-title":"Pers. Ubiquitous Comput."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.procs.2015.08.352","article-title":"HeartHealth: A cardiovascular disease home-based rehabilitation system","volume":"63","author":"Chatzitofis","year":"2015","journal-title":"Procedia Comput. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Mocanu, I., Marian, C., Rusu, L., and Arba, R. (2016, January 8\u201310). A Kinect based adaptive exergame. Proceedings of the 2016 IEEE 12th International Conference on Intelligent Computer Communication and Processing, Cluj-Napoca, Romania.","DOI":"10.1109\/ICCP.2016.7737132"},{"key":"ref_31","unstructured":"Osgouei, R.H., Soulsbv, D., and Bello, F. (2018, January 15\u201317). An Objective Evaluation Method for Rehabilitation Exergames. Proceedings of the 2018 IEEE Games, Entertainment, Media Conference (GEM), Galway, Ireland."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"561","DOI":"10.3233\/IDA-2007-11508","article-title":"Toward accurate dynamic time warping in linear time and space","volume":"11","author":"Salvador","year":"2007","journal-title":"Intell. Data Anal."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"M\u00fcller, M. (2007). Information Retrieval for Music and Motion, Springer.","DOI":"10.1007\/978-3-540-74048-3"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Shokoohi-Yekta, M., Wang, J., and Keogh, E. (May, January 30). On the non-trivial generalization of dynamic time warping to the multi-dimensional case. Proceedings of the 2015 SIAM International Conference on Data Mining, Vancouver, BC, Canada.","DOI":"10.1137\/1.9781611974010.33"},{"key":"ref_35","unstructured":"Lanciault, R. (2019, March 15). Mecanim Humanoids. Available online: https:\/\/blogs.unity3d.com\/2014\/05\/26\/mecanim-humanoids\/."},{"key":"ref_36","unstructured":"Filkov, R. (2018, May 09). K2-Asset On-line Documentation. Available online: https:\/\/ratemt.com\/k2docs\/."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Moon, S., Park, Y., Ko, D.W., and Suh, I.H. (2016). Multiple kinect sensor fusion for human skeleton tracking using Kalman filtering. Int. J. Adv. Robot. Syst., 13.","DOI":"10.5772\/62415"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Karatsidis, A., Bellusci, G., Schepers, H.M., de Zee, M., Andersen, M.S., and Veltink, P.H. (2016). Estimation of ground reaction forces and moments during gait using only inertial motion capture. Sensors, 17.","DOI":"10.3390\/s17010075"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Guo, L., and Xiong, S. (2017). Accuracy of base of support using an inertial sensor based motion capture system. Sensors, 17.","DOI":"10.3390\/s17092091"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"699","DOI":"10.3758\/BRM.40.3.699","article-title":"Interval-level measurement with visual analogue scales in Internet-based research: VAS Generator","volume":"40","author":"Reips","year":"2008","journal-title":"Behav. Res. Methods"},{"key":"ref_41","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_42","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_43","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1016\/j.jbmt.2016.06.007","article-title":"The effects of Tai Chi on physical function and well-being among persons with Parkinson\u2019s Disease: A systematic review","volume":"21","author":"Gallek","year":"2017","journal-title":"J. Bodyw. Mov. Ther."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1467","DOI":"10.1589\/jpts.27.1467","article-title":"Tai chi improves cognitive and physical function in the elderly: A randomized controlled trial","volume":"27","author":"Sun","year":"2015","journal-title":"J. Phys. Ther. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1016\/j.ijnurstu.2011.01.016","article-title":"Guidelines for reporting reliability and agreement studies (GRRAS) were proposed","volume":"48","author":"Kottner","year":"2011","journal-title":"Int. J. Nurs. Stud."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1080\/00140139.2016.1176256","article-title":"Comparison of seven fall risk assessment tools in community-dwelling Korean older women","volume":"60","author":"Kim","year":"2017","journal-title":"Ergonomics"},{"key":"ref_47","unstructured":"Chua, P.T., Crivella, R., Daly, B., Hu, N., Schaaf, R., Ventura, D., Camill, T., Hodgins, J., and Pausch, R. (2003, January 22\u201326). Training for physical tasks in virtual environments: Tai Chi. Proceedings of the IEEE Virtual Reality 2003, Los Angeles, CA, USA."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1704","DOI":"10.1108\/IMDS-03-2015-0087","article-title":"An empirical study of wearable technology acceptance in healthcare","volume":"115","author":"Gao","year":"2015","journal-title":"Ind. Manag. Data Syst."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"513","DOI":"10.2307\/20650307","article-title":"The integrative framework of technology use: An extension and test","volume":"33","author":"Kim","year":"2009","journal-title":"MIS Q."},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Bhattacherjee, A., and Hikmet, N. (2007, January 3\u20136). Physicians\u2019 resistance toward healthcare information technologies: A dual-factor model. Proceedings of 2007 40th the Annual Hawaii International Conference on System Sciences, Waikoloa, HI, USA.","DOI":"10.1109\/HICSS.2007.437"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1057\/ejis.2009.11","article-title":"Threat or coping appraisal: Determinants of SMB executives\u2019 decision to adopt anti-malware software","volume":"18","author":"Lee","year":"2009","journal-title":"Eur. J. Inf. Syst."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/13\/2882\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:02:10Z","timestamp":1760187730000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/13\/2882"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,6,28]]},"references-count":51,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2019,7]]}},"alternative-id":["s19132882"],"URL":"https:\/\/doi.org\/10.3390\/s19132882","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,6,28]]}}}