{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T04:13:29Z","timestamp":1769573609662,"version":"3.49.0"},"reference-count":63,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T00:00:00Z","timestamp":1769472000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia (FCT), Portuguese Ministry of Education, Science and Innovation, NORTE 2020, and European Social Fund of the European Union","award":["2020.05356.BD"],"award-info":[{"award-number":["2020.05356.BD"]}]},{"name":"R&D Units funding","award":["UID\/5210\/2025"],"award-info":[{"award-number":["UID\/5210\/2025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>Symmetry in gait coordination reflects the balanced timing and movement between lower limb joints, which are essential for efficient locomotion and functional independence in older adults. Although gait coordination is recognized as a key indicator of aging-related adaptations and functional decline, most studies rely on isolated measures without fully addressing symmetry in intra- and interlimb coordination. This study aimed to identify principal components of gait coordination symmetry and their association with functional disability in older adults. A cross-sectional study assessed 60 community-dwelling older adults (60+), stratified by functional disability (35 non-disabled; 25 disabled). The three-dimensional range of motion of lower limb joints was assessed during the gait cycle using an optoelectronic system. Intra- and intersegmental coordination was assessed by the continuous relative phase (CRP), a nonlinear measure that captures both timing and movement relationships between joint angles. Principal component analysis was applied to CRP means and coefficients-of-variation (CV) to identify key coordination principal components (PC). Of eight PC explaining 78.86% of variance, only the PC1 distinguished disability status (p = 0.007, d = 0.66). This component included sagittal-plane intrasegmental CRP mean and CV for the knee\u2013ankle and hip\u2013ankle. This study is novel in combining CRP-derived measures of intra- and interlimb symmetry with principal component analysis to distinguish functional disability in older adults. The findings indicate that sagittal-plane intrasegmental CRP symmetry may serve a relevant biomarker of gait impairment. By linking kinematic coordination features to functional disability, this approach complements clinical assessments and supports early identification of mobility decline in older adults.<\/jats:p>","DOI":"10.3390\/sym18020228","type":"journal-article","created":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T15:41:56Z","timestamp":1769528516000},"page":"228","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Principal Component Analysis of Gait Continuous Relative Phase (CRP): Uncovering Lower Limb Coordination Biomarkers for Functional Disability in Older Adults"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0123-4960","authenticated-orcid":false,"given":"Juliana","family":"Moreira","sequence":"first","affiliation":[{"name":"CIR, E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-1898-3487","authenticated-orcid":false,"given":"Leonel A. T.","family":"Alves","sequence":"additional","affiliation":[{"name":"CIR, E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0776-5212","authenticated-orcid":false,"given":"R\u00faben","family":"Oliveira-Sousa","sequence":"additional","affiliation":[{"name":"CIR, E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]},{"given":"M\u00e1rcia","family":"Castro","sequence":"additional","affiliation":[{"name":"E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7394-7604","authenticated-orcid":false,"given":"Rubim","family":"Santos","sequence":"additional","affiliation":[{"name":"CIR, E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9528-1463","authenticated-orcid":false,"given":"Andreia S. P.","family":"Sousa","sequence":"additional","affiliation":[{"name":"CIR, E2S, Polytechnic of Porto, Rua Dr. Ant\u00f3nio Bernardino de Almeida n\u00ba 400, 4200-072 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,27]]},"reference":[{"key":"ref_1","unstructured":"Eurostat (2025, July 30). Difficulties in Personal Care Activities or Household Activities by Sex, Age and Educational Attainment Level. Available online: https:\/\/ec.europa.eu\/eurostat\/databrowser\/product\/page\/HLTH_EHIS_TAE."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/j.gaitpost.2018.02.021","article-title":"Age related differences in segment coordination and its variability during gait","volume":"62","author":"Hafer","year":"2018","journal-title":"Gait Posture"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Adam, C.E., Fitzpatrick, A.L., Leary, C.S., Hajat, A., Ilango, S.D., Park, C., Phelan, E.A., and Semmens, E.O. (2023). Change in gait speed and fall risk among community-dwelling older adults with and without mild cognitive impairment: A retrospective cohort analysis. BMC Geriatr., 23.","DOI":"10.1186\/s12877-023-03890-6"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"10367","DOI":"10.1038\/s41598-020-67251-8","article-title":"Muscle strength and gait speed rather than lean mass are better indicators for poor cognitive function in older men","volume":"10","author":"Sui","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"16915","DOI":"10.1038\/s41598-025-02128-2","article-title":"Predicting fall risk through step width variability at increased gait speed in community dwelling older adults","volume":"15","author":"Kim","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.gaitpost.2018.06.012","article-title":"Do spatiotemporal parameters and gait variability differ across the lifespan of healthy adults? A systematic review","volume":"64","author":"Herssens","year":"2018","journal-title":"Gait Posture"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Hyeon, G., Kim, C., and Shin, S. (2025). The reciprocal relationship between gait and handgrip strength across different age groups. Front. Public Health, 13.","DOI":"10.3389\/fpubh.2025.1557834"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1016\/j.jbiomech.2011.10.028","article-title":"Effect of walking speed on inter-joint coordination differs between young and elderly adults","volume":"45","author":"Chiu","year":"2012","journal-title":"J. Biomech."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.gaitpost.2019.03.001","article-title":"Effect of walking speed on the intersegmental coordination of lower-limb segments in elderly adults","volume":"70","author":"Dewolf","year":"2019","journal-title":"Gait Posture"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1016\/j.gaitpost.2021.02.009","article-title":"Lower-limb coordination and variability during gait: The effects of age and walking surface","volume":"85","author":"Ippersiel","year":"2021","journal-title":"Gait Posture"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"112830","DOI":"10.1016\/j.jbiomech.2025.112830","article-title":"Age-related changes in gait coordination are focused on the step-to-step transition","volume":"189","author":"Alijanpour","year":"2025","journal-title":"J. Biomech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.exger.2016.04.009","article-title":"Gait coordination impairment is associated with mobility in older adults","volume":"80","author":"James","year":"2016","journal-title":"Exp. Gerontol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"103899","DOI":"10.1016\/j.archger.2019.103899","article-title":"Is muscular and functional performance related to gait symmetry in older adults? A systematic review","volume":"84","author":"Guadagnin","year":"2019","journal-title":"Arch. Gerontol. Geriatr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"102558","DOI":"10.1016\/j.bspc.2021.102558","article-title":"Application of continuous relative phase analysis for differentiation of gait in neurodegenerative disease","volume":"67","author":"Jonaitis","year":"2021","journal-title":"Biomed. Signal Process. Control."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"484","DOI":"10.1016\/j.clinbiomech.2014.03.008","article-title":"On the use of continuous relative phase: Review of current approaches and outline for a new standard","volume":"29","author":"Lamb","year":"2014","journal-title":"Clin. Biomech."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1123\/jab.26.1.109","article-title":"Relative phase coordination analysis in the assessment of dynamic gait symmetry","volume":"26","author":"Haddad","year":"2010","journal-title":"J. Appl. Biomech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.jshs.2016.01.013","article-title":"Comparing dynamical systems concepts and techniques for biomechanical analysis","volume":"5","author":"Ducharme","year":"2016","journal-title":"J. Sport Health Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"820","DOI":"10.1093\/gerona\/gls255","article-title":"Independent domains of gait in older adults and associated motor and nonmotor attributes: Validation of a factor analysis approach","volume":"68","author":"Lord","year":"2013","journal-title":"J. Gerontol. Ser. A"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1007\/s40846-017-0297-2","article-title":"Analysis of Big Data in Gait Biomechanics: Current Trends and Future Directions","volume":"38","author":"Phinyomark","year":"2018","journal-title":"J. Med. Biol. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Moreira, J., Silva, B., Faria, H., Santos, R., and Sousa, A.S.P. (2023). Systematic Review on the Applicability of Principal Component Analysis for the Study of Movement in the Older Adult Population. Sensors, 23.","DOI":"10.3390\/s23010205"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1016\/j.jclinepi.2007.11.008","article-title":"The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: Guidelines for Reporting Observational Studies","volume":"61","author":"Altman","year":"2008","journal-title":"J. Clin. Epidemiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/0022-3956(75)90026-6","article-title":"\u201cMini-mental state\u201d: A practical method for grading the cognitive state of patients for the clinician","volume":"12","author":"Folstein","year":"1975","journal-title":"J. Psychiatr. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1381","DOI":"10.1249\/01.MSS.0000078924.61453.FB","article-title":"International physical activity questionnaire: 12-country reliability and validity","volume":"35","author":"Craig","year":"2003","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_24","first-page":"61","article-title":"Functional Evaluation: The Barthel Index","volume":"14","author":"Mahoney","year":"1965","journal-title":"Md. State Med. J."},{"key":"ref_25","first-page":"59","article-title":"Valida\u00e7\u00e3o do \u00edndice de Barthel numa amostra de idosos n\u00e3o institucionalizados","volume":"25","author":"Ribeiro","year":"2007","journal-title":"Rev. Port. Sa\u00fade P\u00fablica"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1093\/geront\/9.3_Part_1.179","article-title":"Assessment of older people: Self-maintaining and instrumental activities of daily living","volume":"9","author":"Lawton","year":"1969","journal-title":"Gerontologist"},{"key":"ref_27","unstructured":"Ara\u00fajo, F., Ribeiro, J.P., Oliveira, A., Pinto, C., and Martins, T. (February, January 31). Valida\u00e7\u00e3o da escala de Lawton e Brody numa amostra de idosos n\u00e3o institucionalizados. Proceedings of the Actas Do 7\u00ba Congresso Nacional de Psicologia Da Sa\u00fade, Lisbon, Portugal."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1146\/annurev.publhealth.25.102802.124401","article-title":"Trends in the health of the elderly","volume":"25","author":"Crimmins","year":"2004","journal-title":"Annu. Rev. Public Health"},{"key":"ref_29","first-page":"24","article-title":"Hand Force of Men and Women Over 65 Years of Age as Measured by Maximum Pinch and Grip Force","volume":"16","author":"Jansen","year":"2008","journal-title":"J. Aging Phys. Act."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Moreira, J.S., Melo, A., Santos, R., and Sousa, A.S.P. (2022). Indicators and Instruments to Assess Components of Disability in Community-Dwelling Older Adults: A Systematic Review. Sensors, 22.","DOI":"10.3390\/s22218270"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"562","DOI":"10.1016\/j.clinbiomech.2011.01.015","article-title":"Multi-segment trunk kinematics during locomotion and elementary exercises","volume":"26","author":"Leardini","year":"2011","journal-title":"Clin. Biomech."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Moreira, J., Cunha, B., F\u00e9lix, J., Santos, R., and Sousa, A.S.P. (2025). Kinematic and Kinetic Gait Principal Component Domains in Older Adults With and Without Functional Disability: A Cross-Sectional Study. J. Funct. Morphol. Kinesiol., 10.","DOI":"10.3390\/jfmk10020140"},{"key":"ref_33","unstructured":"van Sint Jan, S. (2007). Color Atlas of Skeletal Landmark Definitions\u2014Guidelines for Reproducible Manual and Virtual Palpations, Churchill Livingstone. [1st ed.]."},{"key":"ref_34","unstructured":"Qualisys, A. (2011). Qualisys Track Maneger\u2014User Manual, Qualisys AB."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.gaitpost.2017.11.010","article-title":"Are there associations with age and sex in walking stability in healthy older adults?","volume":"60","author":"Hettinga","year":"2018","journal-title":"Gait Posture"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.ijge.2015.05.010","article-title":"The Forward Velocity of the Center of Pressure in the Midfoot is a Major Predictor of Gait Speed in Older Adults","volume":"9","author":"Fuchioka","year":"2015","journal-title":"Int. J. Gerontol."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Svoboda, Z., Bizovska, L., Janura, M., Kubonova, E., Janurova, K., and Vuillerme, N. (2017). Variability of spatial temporal gait parameters and center of pressure displacements during gait in elderly fallers and nonfallers: A 6-month prospective study. PLoS ONE, 12.","DOI":"10.1371\/journal.pone.0171997"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Castro, M., Moreira, J., and Sousa, A.S.P. (2025). Association Between Gait Lower Limb Intra and Interlimb Coordination and Fear of Falling and Falling History in Older Adults. Symmetry, 17.","DOI":"10.3390\/sym17060818"},{"key":"ref_39","unstructured":"Hair, J., Tatham, R., Anderson, R., and Black, W. (1998). Multivariate Data Analysis, Prentice-Hall. [5th ed.]."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1016\/j.clinbiomech.2013.03.001","article-title":"Variability in inter-joint coordination during walking of elderly adults and its association with clinical balance measures","volume":"28","author":"Chiu","year":"2013","journal-title":"Clin. Biomech."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Sadeghi, H., Shojaedin, S.S., Abbasi, A., Alijanpour, E., Vieira, M.F., Svoboda, Z., and Nazarpour, K. (2021). Lower-Extremity Intra-Joint Coordination and Its Variability between Fallers and Non-Fallers during Gait. Appl. Sci., 11.","DOI":"10.3390\/app11062840"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"382","DOI":"10.3390\/medicina46060054","article-title":"Motor control theories and their applications","volume":"46","author":"Latash","year":"2010","journal-title":"Medicina"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1226","DOI":"10.1038\/nn963","article-title":"Optimal feedback control as a theory of motor coordination","volume":"5","author":"Todorov","year":"2002","journal-title":"Nat. Neurosci."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Letournel, A., Marques, M., Vig\u00e1rio, R., Quint\u00e3o, C., and Quaresma, C. (2025). Biomechanical Characterisation of Gait in Older Adults: A Cross-Sectional Study Using Inertial Sensor-Based Motion Capture. Bioengineering, 12.","DOI":"10.3390\/bioengineering12080889"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1016\/j.gaitpost.2023.10.024","article-title":"Inter-segment coordination amplitude and variability during gait in patients with knee osteoarthritis and asymptomatic adults","volume":"107","author":"Robbins","year":"2024","journal-title":"Gait Posture"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.gaitpost.2016.04.018","article-title":"The association between intersegmental coordination in the lower limb and gait speed in elderly females","volume":"48","author":"Ogaya","year":"2016","journal-title":"Gait Posture"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.gaitpost.2021.06.018","article-title":"Foot and ankle biomechanics during walking in older adults: A systematic review and meta-analysis of observational studies","volume":"89","author":"Pol","year":"2021","journal-title":"Gait Posture"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"De Luca, M., Minino, R., Polverino, A., Gallo, E., Mandolesi, L., Sorrentino, P., Sorrentino, G., and Lopez, E.T. (2025). The Effects of Aging and Cognition on Gait Coordination Analyzed Through a Network Analysis Approach. Biomechanics, 5.","DOI":"10.20944\/preprints202505.0718.v1"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1111\/j.1748-1716.2006.01522.x","article-title":"Metabolic cost, mechanical work, and efficiency during walking in young and older men","volume":"186","author":"Mian","year":"2006","journal-title":"Acta Physiol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/S0966-6362(03)00062-6","article-title":"Muscle force redistributes segmental power for body progression during walking","volume":"19","author":"Neptune","year":"2004","journal-title":"Gait Posture"},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Muehleman, C., Margulis, A., Bae, W.C., and Masuda, K. (2010). Relationship between knee and ankle degeneration in a population of organ donors. BMC Med., 8.","DOI":"10.1186\/1741-7015-8-48"},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Gordon, D., Robertson, E., Caldwell, G.E., Hamill, J., Kamen, G., and Whittlesey, S.N. (2014). Research Methods in Biomechanics, Human Kinetics. [2nd ed.].","DOI":"10.5040\/9781492595809"},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Stenum, J., Hsu, M.M., Pantelyat, A.Y., and Roemmich, R.T. (2024). Clinical gait analysis using video-based pose estimation: Multiple perspectives, clinical populations, and measuring change. PLoS Digit. Health, 3.","DOI":"10.1371\/journal.pdig.0000467"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"525","DOI":"10.2519\/jospt.2014.5028","article-title":"The influence of hip strength on lower-limb, pelvis, and trunk kinematics and coordination patterns during walking and hopping in healthy women","volume":"44","author":"Smith","year":"2014","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"645","DOI":"10.2147\/CIA.S246998","article-title":"The Role of Hip Abductor Strength in Identifying Older Persons at Risk of Falls: A Diagnostic Accuracy Study","volume":"15","author":"Gafner","year":"2020","journal-title":"Clin. Interv. Aging"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1007\/s00421-007-0613-6","article-title":"Identification of elderly fallers by muscle strength measures","volume":"102","author":"Pijnappels","year":"2008","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1282","DOI":"10.1016\/j.jbiomech.2009.03.009","article-title":"Modular control of human walking: A simulation study","volume":"42","author":"Neptune","year":"2009","journal-title":"J. Biomech."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1007\/s40520-019-01210-w","article-title":"Gait symmetry in the dual task condition as a predictor of future falls among independent older adults: A 2-year longitudinal study","volume":"31","author":"Gillain","year":"2019","journal-title":"Aging Clin. Exp. Res."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"2042098620933741","DOI":"10.1177\/2042098620933741","article-title":"An overview of prevalence, determinants and health outcomes of polypharmacy","volume":"11","author":"Khezrian","year":"2020","journal-title":"Ther. Adv. Drug Saf."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"624","DOI":"10.1016\/j.jamda.2017.02.009","article-title":"Polypharmacy Is Associated With Higher Frailty Risk in Older People: An 8-Year Longitudinal Cohort Study","volume":"18","author":"Veronese","year":"2017","journal-title":"J. Am. Med. Dir. Assoc."},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"Salm, C., Sauer, J., Binder, N., Pfefferle, A., Sofroniou, M., Metzner, G., Farin-Glattacker, E., Voigt-Radloff, S., and Maun, A. (2022). Over- and under-prescribing, and their association with functional disability in older patients at risk of further decline in Germany\u2014A cross-sectional survey conducted as part of a randomised comparative effectiveness trial. BMC Geriatr., 22.","DOI":"10.1186\/s12877-022-03242-w"},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Zhao, J., Han, W., and Tang, H. (2023). Lower limbs inter-joint coordination and variability during typical Tai Chi movement in older female adults. Front. Physiol., 14.","DOI":"10.3389\/fphys.2023.1164923"},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1186\/s40101-022-00298-w","article-title":"Effects of exercise habituation and aging on the intersegmental coordination of lower limbs during walking with sinusoidal speed change","volume":"41","author":"Abe","year":"2022","journal-title":"J. Physiol. Anthropol."}],"container-title":["Symmetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-8994\/18\/2\/228\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T15:56:20Z","timestamp":1769529380000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-8994\/18\/2\/228"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,27]]},"references-count":63,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["sym18020228"],"URL":"https:\/\/doi.org\/10.3390\/sym18020228","relation":{},"ISSN":["2073-8994"],"issn-type":[{"value":"2073-8994","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,27]]}}}