{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,14]],"date-time":"2026-02-14T04:31:46Z","timestamp":1771043506125,"version":"3.50.1"},"reference-count":55,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2020,12,5]],"date-time":"2020-12-05T00:00:00Z","timestamp":1607126400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003130","name":"Fonds Wetenschappelijk Onderzoek","doi-asserted-by":"publisher","award":["T004716N"],"award-info":[{"award-number":["T004716N"]}],"id":[{"id":"10.13039\/501100003130","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>(1) Background: Joint loading is an important parameter in patients with osteoarthritis (OA). However, calculating joint loading relies on the performance of an extensive biomechanical analysis, which is not possible to do in a free-living situation. We propose the concept and design of a novel blended-care app called JOLO (Joint Load) that combines free-living information on activity with lab-based measures of joint loading in order to estimate a subject\u2019s functional status. (2) Method: We used an iterative design process to evaluate the usability of the JOLO app through questionnaires. The user interfaces that resulted from the iterations are described and provide a concept for feedback on functional status. (3) Results: In total, 44 people (20 people with OA and 24 health-care providers) participated in the testing of the JOLO app. OA patients rated the latest version of the JOLO app as moderately useful. Therapists were predominantly positive; however, their intention to use JOLO was low due to technological issues. (4) Conclusion: We can conclude that JOLO is promising, but further technological improvements concerning activity recognition, the development of personalized joint loading predictions and a more comfortable means to carry the device are needed to facilitate its integration as a blended-care program.<\/jats:p>","DOI":"10.3390\/s20236967","type":"journal-article","created":{"date-parts":[[2020,12,7]],"date-time":"2020-12-07T21:37:42Z","timestamp":1607377062000},"page":"6967","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Towards the Monitoring of Functional Status in a Free-Living Environment for People with Hip or Knee Osteoarthritis: Design and Evaluation of the JOLO Blended Care App"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9218-7604","authenticated-orcid":false,"given":"Jill","family":"Emmerzaal","sequence":"first","affiliation":[{"name":"Human Movement Biomechanics Research Group, Department of Movement Sciences, KU Leuven, 3000 Leuven, Belgium"},{"name":"REVAL Rehabilitation Research, Hasselt University, 3590 Diepenbeek, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Arne","family":"De Brabandere","sequence":"additional","affiliation":[{"name":"Declarative Languages and Artificial Intelligence Group, Department of Computer Science, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yves","family":"Vanrompay","sequence":"additional","affiliation":[{"name":"Instituut voor Mobiliteit, Hasselt University, 3590 Diepenbeek, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2691-0569","authenticated-orcid":false,"given":"Julie","family":"Vranken","sequence":"additional","affiliation":[{"name":"Mobile Health Unit, Faculty of Medicine and Life Sciences, Hasselt University, 3590 Diepenbeek, Belgium"},{"name":"Department of Orthopedics and Future Health, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Valerie","family":"Storms","sequence":"additional","affiliation":[{"name":"Mobile Health Unit, Faculty of Medicine and Life Sciences, Hasselt University, 3590 Diepenbeek, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1370-2090","authenticated-orcid":false,"given":"Liesbet","family":"De Baets","sequence":"additional","affiliation":[{"name":"REVAL Rehabilitation Research, Hasselt University, 3590 Diepenbeek, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kristoff","family":"Corten","sequence":"additional","affiliation":[{"name":"Department of Orthopedics and Future Health, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3748-9263","authenticated-orcid":false,"given":"Jesse","family":"Davis","sequence":"additional","affiliation":[{"name":"Declarative Languages and Artificial Intelligence Group, Department of Computer Science, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7611-3747","authenticated-orcid":false,"given":"Ilse","family":"Jonkers","sequence":"additional","affiliation":[{"name":"Human Movement Biomechanics Research Group, Department of Movement Sciences, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Benedicte","family":"Vanwanseele","sequence":"additional","affiliation":[{"name":"Human Movement Biomechanics Research Group, Department of Movement Sciences, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5461-947X","authenticated-orcid":false,"given":"Annick","family":"Timmermans","sequence":"additional","affiliation":[{"name":"REVAL Rehabilitation Research, Hasselt University, 3590 Diepenbeek, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,5]]},"reference":[{"key":"ref_1","first-page":"646","article-title":"Burden of major musculoskeletal conditions","volume":"81","author":"Woolf","year":"2003","journal-title":"Bull. World Health Organ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.joca.2012.09.012","article-title":"Osteoarthritis as a disease of mechanics","volume":"21","author":"Felson","year":"2013","journal-title":"Osteoarthr. Cartil."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1097\/BOR.0b013e328307f58c","article-title":"Abnormal and cumulative loading in knee osteoarthritis","volume":"20","author":"Maly","year":"2008","journal-title":"Curr. Opin. Rheumatol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1016\/j.joca.2016.09.023","article-title":"Osteoarthritis year in review 2016: Mechanics","volume":"25","author":"Saxby","year":"2017","journal-title":"Osteoarthr. Cartil."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1136\/ard.61.7.617","article-title":"Dynamic load at baseline can predict radiographic disease progression in medial compartment knee osteoarthritis","volume":"61","author":"Miyazaki","year":"2002","journal-title":"Ann. Rheum. Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1291","DOI":"10.1016\/j.joca.2017.02.796","article-title":"Daily cumulative hip moment is associated with radiographic progression of secondary hip osteoarthritis","volume":"25","author":"Tateuchi","year":"2017","journal-title":"Osteoarthr. Cartil."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"154","DOI":"10.3390\/jfmk1020154","article-title":"The effect of mechanical loading on articular cartilage","volume":"1","author":"Musumeci","year":"2016","journal-title":"J. Funct. Morphol. Kinesiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1016\/j.joca.2014.01.003","article-title":"OARSI guidelines for the non-surgical management of knee osteoarthritis","volume":"22","author":"McAlindon","year":"2014","journal-title":"Osteoarthr. Cartil."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1056\/NEJM199009133231106","article-title":"Total hip and total knee replacement","volume":"323","author":"Harris","year":"1990","journal-title":"N. Engl. J. Med."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Ernstg\u00e5rd, A., PirouziFard, M., and Thorstensson, C.A. (2017). Health enhancing physical activity in patients with hip or knee osteoarthritis-an observational intervention study. BMC Musculoskelet. Disord., 18.","DOI":"10.1186\/s12891-017-1394-7"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1943","DOI":"10.1002\/cphy.c100057","article-title":"Exercise and osteoarthritis: Cause and effects","volume":"1","author":"Bennell","year":"2011","journal-title":"Compr. Physiol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Zampogna, B., Papalia, R., Papalia, G.F., Campi, S., Vasta, S., Vorini, F., Fossati, C., Torre, G., and Denaro, V. (2020). The Role of Physical Activity as Conservative Treatment for Hip and Knee Osteoarthritis in Older People: A Systematic Review and Meta-Analysis. J. Clin. Med., 9.","DOI":"10.3390\/jcm9041167"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"162","DOI":"10.2519\/jospt.2018.7459","article-title":"Knee joint loading in healthy adults during functional exercises: Implications for rehabilitation guidelines","volume":"48","author":"Smith","year":"2018","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1167","DOI":"10.1002\/jor.20655","article-title":"In vivo knee loading characteristics during activities of daily living as measured by an instrumented total knee replacement","volume":"26","author":"Dyrby","year":"2008","journal-title":"J. Orthop. Res."},{"key":"ref_15","unstructured":"Corlan, A.D. (2020, June 22). Medline Trend: Automated Yearly Statistics of PubMed Results for Any Query. Available online: http:\/\/dan.corlan.net\/medline-trend.html."},{"key":"ref_16","unstructured":"(2020, October 08). Deloitte\u2019s 2019 Global Mobile Consumer Survey. Available online: https:\/\/www2.deloitte.com\/us\/en\/insights\/industry\/telecommunications\/global-mobile-consumer-survey.html."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Palestra, G., Rebiai, M., Courtial, E., and Koutsouris, D. (2019). Evaluation of a Rehabilitation System for the Elderly in a Day Care Center. Information, 10.","DOI":"10.3390\/info10010003"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e12053","DOI":"10.2196\/12053","article-title":"Can smartphone apps increase physical activity? Systematic review and meta-analysis","volume":"21","author":"Romeo","year":"2019","journal-title":"J. Med. Internet Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1186\/s12966-014-0097-9","article-title":"Apps to promote physical activity among adults: A review and content analysis","volume":"11","author":"Middelweerd","year":"2014","journal-title":"Int. J. Behav. Nutr. Phys. Act."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e11","DOI":"10.2196\/mhealth.7734","article-title":"Usage of an exercise app in the care for people with osteoarthritis: User-driven exploratory study","volume":"6","author":"Villadsen","year":"2018","journal-title":"JMIR mHealth uHealth"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1177\/1090198104263660","article-title":"Health promotion by social cognitive means","volume":"31","author":"Bandura","year":"2004","journal-title":"Health Educ. Behav."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.berh.2014.01.009","article-title":"Exercise in osteoarthritis: Moving from prescription to adherence","volume":"28","author":"Bennell","year":"2014","journal-title":"Best Pract. Res. Clin. Rheumatol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e22","DOI":"10.2196\/resprot.3795","article-title":"Development of a web-based and mobile app to support physical activity in individuals with rheumatoid arthritis: Results from the second step of a co-design process","volume":"4","author":"Opava","year":"2015","journal-title":"JMIR Res. Protoc."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"e223","DOI":"10.2196\/jmir.2742","article-title":"Adherence to a web-based physical activity intervention for patients with knee and\/or hip osteoarthritis: A mixed method study","volume":"15","author":"Bossen","year":"2013","journal-title":"J. Med. Internet Res."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kloek, C.J., Bossen, D., Veenhof, C., van Dongen, J.M., Dekker, J., and de Bakker, D.H. (2014). Effectiveness and cost-effectiveness of a blended exercise intervention for patients with hip and\/or knee osteoarthritis: Study protocol of a randomized controlled trial. BMC Musculoskelet. Disord., 15.","DOI":"10.1186\/1471-2474-15-269"},{"key":"ref_26","first-page":"3","article-title":"A public domain dataset for human activity recognition using smartphones","volume":"3","author":"Anguita","year":"2013","journal-title":"Esann"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2059","DOI":"10.3390\/s150102059","article-title":"A survey of online activity recognition using mobile phones","volume":"15","author":"Shoaib","year":"2015","journal-title":"Sensors"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.neucom.2018.03.067","article-title":"Time series feature extraction on basis of scalable hypothesis tests (tsfresh\u2013a python package)","volume":"307","author":"Christ","year":"2018","journal-title":"Neurocomputing"},{"key":"ref_29","unstructured":"Prokhorenkova, L., Gusev, G., Vorobev, A., Dorogush, A.V., and Gulin, A. (2018, January 3\u20138). CatBoost: Unbiased boosting with categorical features. Proceedings of the Advances in neural information processing systems, Montr\u00e9al, QC, Canada."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1674","DOI":"10.1249\/01.mss.0000227641.68360.c2","article-title":"Improving the accuracy of pedometer used by the elderly with the FFT algorithm","volume":"38","author":"Kuwae","year":"2006","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_31","unstructured":"Emmerzaal, J., van der Straaten, R., Wesseling, M., Bruijnes, A., Corten, K., De Baets, L., Jonkers, I., Timmermans, A., and Vanwanseele, B. (August, January 31). Hip cf impulse during stair descent best discriminates between healthy controls and hip osteoarthritis patients. Proceedings of the International Society of Biomechanics, Calgary, AB, Canada."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1940","DOI":"10.1109\/TBME.2007.901024","article-title":"OpenSim: Open-source software to create and analyze dynamic simulations of movement","volume":"54","author":"Delp","year":"2007","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1002\/jor.22852","article-title":"Gait alterations to effectively reduce hip contact forces","volume":"33","author":"Wesseling","year":"2015","journal-title":"J. Orthop. Res."},{"key":"ref_34","unstructured":"WHO (2020, July 14). Global Recommendations on Physical Activity for Health. Available online: https:\/\/apps.who.int\/iris\/bitstream\/handle\/10665\/44399\/9789241599979_eng.pdf;jsessionid=D74E29638A8D93ACAAF90CA1C8D671F1?sequence=1."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1080\/10447318.2014.930311","article-title":"Usability: Lessons learned and yet to be learned","volume":"30","author":"Lewis","year":"2014","journal-title":"Int. J. Hum. Comput. Interact."},{"key":"ref_36","first-page":"4","article-title":"SUS-A quick and dirty usability scale","volume":"189","author":"Brooke","year":"1996","journal-title":"Usability Eval. Ind."},{"key":"ref_37","first-page":"3","article-title":"Measuring usability with the use questionnaire12","volume":"8","author":"Lund","year":"2001","journal-title":"Usability Interface"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"425","DOI":"10.2307\/30036540","article-title":"User acceptance of information technology: Toward a unified view","volume":"27","author":"Venkatesh","year":"2003","journal-title":"MIS Q."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/S0005-7916(00)00012-4","article-title":"Psychometric properties of the credibility\/expectancy questionnaire","volume":"31","author":"Devilly","year":"2000","journal-title":"J. Behav. Ther. Exp. Psychiatry"},{"key":"ref_40","first-page":"29","article-title":"SUS: A retrospective","volume":"8","author":"Brooke","year":"2013","journal-title":"J. Usability Stud."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1080\/10447318.2018.1455307","article-title":"The system usability scale: Past, present, and future","volume":"34","author":"Lewis","year":"2018","journal-title":"Int. J. Hum. Comput. Interact."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Allen, M., Poggiali, D., Whitaker, K., Marshall, T.R., and Kievit, R.A. (2019). Raincloud plots: A multi-platform tool for robust data visualization. [version 1; peer review: 2 approved]. Wellcome Open Res., 4.","DOI":"10.12688\/wellcomeopenres.15191.1"},{"key":"ref_43","unstructured":"Whitaker, K., van Mourik, T., Martinez, P.A., Poggiali, D., Ye, H. (2019). RainCloudPlots\/RainCloudPlots: WellcomeOpenResearch. Wellcome Open Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1109\/2.241424","article-title":"Iterative user-interface design","volume":"26","author":"Nielsen","year":"1993","journal-title":"Computer"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"771","DOI":"10.1089\/dia.2014.0062","article-title":"Are Patients with Diabetes Mellitus Satisfied with Technologies Used to Assist with Diabetes Management and Coping? A Structured Review","volume":"16","author":"Harrison","year":"2014","journal-title":"Diabetes Technol. Ther."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1002\/acr.22015","article-title":"Biomechanical deviations during level walking associated with knee osteoarthritis: A systematic review and meta-analysis","volume":"65","author":"Mills","year":"2013","journal-title":"Arthritis Care Res."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.gaitpost.2017.09.020","article-title":"Hip movement pathomechanics of patients with hip osteoarthritis aim at reducing hip joint loading on the osteoarthritic side","volume":"59","author":"Meyer","year":"2018","journal-title":"Gait Posture"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"e12651","DOI":"10.2196\/12651","article-title":"Perspectives of People Who Are Overweight and Obese on Using Wearable Technology for Weight Management: Systematic Review","volume":"8","author":"Hu","year":"2020","journal-title":"JMIR mHealth uHealth"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1093\/jamia\/ocv052","article-title":"m-Health adoption by healthcare professionals: A systematic review","volume":"23","author":"Gagnon","year":"2016","journal-title":"J. Am. Med. Inform. Assoc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/j.joca.2019.12.003","article-title":"Osteoarthritis year in review 2019: Mechanics","volume":"28","author":"Hunt","year":"2020","journal-title":"Osteoarthr. Cartil."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1109\/TBME.2018.2854632","article-title":"Predicting athlete ground reaction forces and moments from spatio-temporal driven CNN models","volume":"66","author":"Johnson","year":"2018","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Lim, H., Kim, B., and Park, S. (2020). Prediction of lower limb kinetics and kinematics during walking by a single IMU on the lower back using machine learning. Sensors, 20.","DOI":"10.3390\/s20010130"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"109327","DOI":"10.1016\/j.jbiomech.2019.109327","article-title":"A probabilistic method to estimate gait kinetics in the absence of ground reaction force measurements","volume":"96","author":"Tanghe","year":"2019","journal-title":"J. Biomech."},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Stetter, B.J., Ringhof, S., Krafft, F.C., Sell, S., and Stein, T. (2019). Estimation of knee joint forces in sport movements using wearable sensors and machine learning. Sensors, 19.","DOI":"10.3390\/s19173690"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"320","DOI":"10.3389\/fbioe.2020.00320","article-title":"A Machine Learning Approach to Estimate Hip and Knee Joint Loading Using a Mobile Phone-Embedded IMU","volume":"8","author":"Emmerzaal","year":"2020","journal-title":"Front. Bioeng. Biotechnol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6967\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:41:31Z","timestamp":1760179291000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/23\/6967"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,5]]},"references-count":55,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["s20236967"],"URL":"https:\/\/doi.org\/10.3390\/s20236967","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,5]]}}}