{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T04:58:28Z","timestamp":1777870708769,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,12,24]],"date-time":"2023-12-24T00:00:00Z","timestamp":1703376000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"Korea government (MSIT)","doi-asserted-by":"publisher","award":["RS-2023-00222406"],"award-info":[{"award-number":["RS-2023-00222406"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>Abrupt changes in gait speed can interfere with the symmetry of the overall gait apparatus and result in unstable joint movement patterns. Because unstable joint movements may cause slips, trips, and falls, it is necessary to quantitatively characterize the changes in joint movement patterns in response to sudden speed changes. The purpose of this study is to examine how abrupt changes in gait speed affect gait dynamics. Twenty-two healthy young subjects walked for four minutes, including a warm-up period, under three different speed conditions. Utilizing nonlinear dynamics tools, including the maximum Lyapunov exponent, Sample Entropy, and Detrended Fluctuation Analysis, we quantitatively assessed gait dynamics for the different speed conditions. Our findings highlight how different speed change patterns impact joint instability, notably within the knee joint during gait (p &lt; 0.05). Furthermore, introducing a resting phase during random speed changes exhibited the potential to restore gait symmetry and control movement patterns. This research offers valuable insights into human gait stability dynamics, especially concerning sudden speed changes. Understanding how controlled speed variations affect gait and joint instability informs fall prevention and rehabilitation strategies, emphasizing speed management to improve gait symmetry and reduce joint instability.<\/jats:p>","DOI":"10.3390\/sym16010026","type":"journal-article","created":{"date-parts":[[2023,12,24]],"date-time":"2023-12-24T20:44:15Z","timestamp":1703450655000},"page":"26","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Dynamic Stability of Human Walking in Response to Sudden Speed Changes"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5618-9119","authenticated-orcid":false,"given":"Chaneun","family":"Park","sequence":"first","affiliation":[{"name":"The Department of Mechatronics Engineering, Incheon National University, Incheon 22012, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3188-000X","authenticated-orcid":false,"given":"Kiwon","family":"Park","sequence":"additional","affiliation":[{"name":"The Department of Mechatronics Engineering, Incheon National University, Incheon 22012, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1271","DOI":"10.1136\/ard.2006.062927","article-title":"The relationship between toe-out angle during gait and progression of medial tibiofemoral osteoarthritis","volume":"66","author":"Chang","year":"2007","journal-title":"Ann. Rheum. Dis."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/0167-2789(85)90011-9","article-title":"Determining Lyapunov exponents from a time series","volume":"16","author":"Wolf","year":"1985","journal-title":"Phys. D Nonlinear Phenom."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1880","DOI":"10.1002\/acr.22391","article-title":"Characteristics associated with hallux valgus in a population-based foot study of older adults","volume":"66","author":"Dufour","year":"2014","journal-title":"Arthritis Care Res."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1152\/advan.00181.2017","article-title":"Detrended fluctuation analysis in a simple spreadsheet as a tool for teaching fractal physiology","volume":"42","author":"Arsac","year":"2018","journal-title":"Adv. Physiol. Educ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1016\/j.medengphy.2011.07.024","article-title":"Maximum Lyapunov exponents as predictors of global gait stability: A modelling approach","volume":"34","author":"Bruijn","year":"2012","journal-title":"Med. Eng. Phys."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1237","DOI":"10.1038\/s41598-020-79584-5","article-title":"The effects of walking speed and mobile phone use on the walking dynamics of young adults","volume":"11","author":"Crowley","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1016\/j.gaitpost.2009.12.002","article-title":"An empirical examination of detrended fluctuation analysis for gait data","volume":"31","author":"Damouras","year":"2010","journal-title":"Gait Posture"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"95","DOI":"10.5334\/paah.57","article-title":"A current review of foot disorder and plantar pressure alternation in the elderly","volume":"4","author":"Zhang","year":"2020","journal-title":"Phys. Act. Health"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1186\/1743-0003-9-8","article-title":"Wearing a safety harness during treadmill walking influences lower extremity kinematics mainly through changes in ankle regularity and local stability","volume":"9","author":"Decker","year":"2012","journal-title":"J. NeuroEngineering Rehabil."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1016\/j.jbiomech.2004.12.014","article-title":"Kinematic variability and local dynamic stability of upper body motions when walking at different speeds","volume":"39","author":"Dingwell","year":"2006","journal-title":"J. Biomech."},{"key":"ref_11","first-page":"857","article-title":"Prevalence and associations of hallux valgus in a primary care population","volume":"59","author":"Roddy","year":"2008","journal-title":"Arthritis Care Res. Off. J. Am. Coll. Rheumatol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/j.maturitas.2018.10.001","article-title":"Foot problems as a risk factor for falls in community-dwelling older people: A systematic review and meta-analysis","volume":"118","author":"Menz","year":"2018","journal-title":"Maturitas"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1016\/j.gaitpost.2005.09.002","article-title":"Clinical determinants of plantar forces and pressures during walking in older people","volume":"24","author":"Menz","year":"2006","journal-title":"Gait Posture"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1159\/000086373","article-title":"Footwear characteristics and foot problems in older people","volume":"51","author":"Menz","year":"2005","journal-title":"Gerontology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.gaitpost.2020.01.023","article-title":"Redistribution of joint moments and work in older women with and without hallux valgus at two walking speeds","volume":"77","author":"Buddhadev","year":"2020","journal-title":"Gait Posture"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.clinbiomech.2009.12.003","article-title":"Stability and variability of knee kinematics during gait in knee osteoarthritis before and after replacement surgery","volume":"25","author":"Yakhdani","year":"2010","journal-title":"Clin. Biomech."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1016\/j.humov.2007.05.003","article-title":"Gait dynamics, fractals and falls: Finding meaning in the stride-to-stride fluctuations of human walking","volume":"26","author":"Hausdorff","year":"2007","journal-title":"Hum. Mov. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"564","DOI":"10.1515\/cdbme-2022-1144","article-title":"On Gait Stability: Correlations between Lyapunov Exponent and Stride Time Variability","volume":"Volume 8","author":"Chandrasekaran","year":"2022","journal-title":"Current Directions in Biomedical Engineering"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Promsri, A., Cholamjiak, P., and Federolf, P. (2023). Walking Stability and Risk of Falls. Bioengineering, 10.","DOI":"10.3390\/bioengineering10040471"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"102891","DOI":"10.1016\/j.humov.2021.102891","article-title":"Effective detection of abnormal gait patterns in Parkinson\u2019s disease patients using kinematics, nonlinear, and stability gait features","volume":"81","year":"2022","journal-title":"Hum. Mov. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"562","DOI":"10.3389\/fphys.2020.00562","article-title":"Assessing the temporal organization of walking variability: A systematic review and consensus guidelines on detrended fluctuation analysis","volume":"11","author":"Ravi","year":"2020","journal-title":"Front. Physiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/j.gaitpost.2019.09.017","article-title":"Minimal effects of age and prolonged physical and mental exercise on healthy adults\u2019 gait","volume":"74","author":"Zijdewind","year":"2019","journal-title":"Gait Posture"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1115\/1.1336798","article-title":"Local dynamic stability versus kinematic variability of continuous overground and treadmill walking","volume":"123","author":"Dingwell","year":"2001","journal-title":"J. Biomech. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3070","DOI":"10.1152\/jn.2002.87.6.3070","article-title":"Control of foot trajectory in human locomotion: Role of ground contact forces in simulated reduced gravity","volume":"87","author":"Ivanenko","year":"2002","journal-title":"J. Neurophysiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"848","DOI":"10.1063\/1.1324008","article-title":"Nonlinear time series analysis of normal and pathological human walking","volume":"10","author":"Dingwell","year":"2000","journal-title":"Chaos Interdiscip. J. Nonlinear Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.gaitpost.2006.08.010","article-title":"Walking speed influences on gait cycle variability","volume":"26","author":"Jordan","year":"2007","journal-title":"Gait Posture"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1167","DOI":"10.1682\/JRRD.2007.10.0168","article-title":"Optimizing footwear for older people at risk of falls","volume":"45","author":"Menant","year":"2008","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.gaitpost.2010.03.017","article-title":"The impact of hallux valgus on foot kinematics: A cross-sectional, comparative study","volume":"32","author":"Deschamps","year":"2010","journal-title":"Gait Posture"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.gaitpost.2012.01.016","article-title":"Characterization of spatiotemporally complex gait patterns using cross-correlation signatures","volume":"36","author":"Park","year":"2012","journal-title":"Gait Posture"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/j.gaitpost.2014.02.011","article-title":"Gait changes in individuals with bilateral hallux valgus reduce first metatarsophalangeal loading but increase knee abductor moments","volume":"40","author":"Shih","year":"2014","journal-title":"Gait Posture"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1186\/1743-0003-8-2","article-title":"Gait stability and variability measures show effects of impaired cognition and dual tasking in frail people","volume":"8","author":"Lamoth","year":"2011","journal-title":"J. Neuroeng. Rehabil."},{"key":"ref_32","first-page":"H1643","article-title":"Physiological time-series analysis: What does regularity quantify?","volume":"266","author":"Pincus","year":"1994","journal-title":"Am. J. Physiol."},{"key":"ref_33","first-page":"H2039","article-title":"Physiological time series analysis using approximate entropy and sample entropy","volume":"278","author":"Richman","year":"2000","journal-title":"Am. J. Physiol."},{"key":"ref_34","unstructured":"Taylor & Francis Group (2016). Nonlinear Analysis for Human Movement Variability, CRC Press."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Lubetzky, A.V., Harel, D., and Lubetzky, E. (2018). On the effects of signal processing on sample entropy for postural control. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0193460"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1016\/j.gaitpost.2006.10.008","article-title":"The influence of foot progression angle on the knee adduction moment during walking and stair climbing in pain free individuals with knee osteoarthritis","volume":"26","author":"Guo","year":"2007","journal-title":"Gait Posture"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"13736","DOI":"10.1038\/s41598-021-93037-7","article-title":"Stabilization demands of walking modulate the vestibular contributions to gait","volume":"11","author":"Magnani","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"McCrum, C., Karamanidis, K., Willems, P., Zijlstra, W., and Meijer, K. (2018). Retention, savings and interlimb transfer of reactive gait adaptations in humans following unexpected perturbations. Commun. Biol., 1.","DOI":"10.1038\/s42003-018-0238-9"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.jbiomech.2017.09.009","article-title":"Effect of noise and filtering on largest Lyapunov exponent of time series associated with human walking","volume":"64","author":"Mehdizadeh","year":"2017","journal-title":"J. Biomech."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1016\/j.humov.2017.06.003","article-title":"The impact of speed and time on gait dynamics","volume":"54","author":"Thomas","year":"2017","journal-title":"Hum. Mov. Sci."}],"container-title":["Symmetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-8994\/16\/1\/26\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:41:21Z","timestamp":1760132481000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-8994\/16\/1\/26"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,12,24]]},"references-count":40,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2024,1]]}},"alternative-id":["sym16010026"],"URL":"https:\/\/doi.org\/10.3390\/sym16010026","relation":{},"ISSN":["2073-8994"],"issn-type":[{"value":"2073-8994","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,12,24]]}}}