{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T06:51:49Z","timestamp":1780987909532,"version":"3.54.1"},"reference-count":59,"publisher":"Public Library of Science (PLoS)","issue":"12","license":[{"start":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T00:00:00Z","timestamp":1764633600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Clinical measures of walking capacity may differ from walking performed in outdoor environmental settings. This study assessed spatiotemporal aspects of gait in individuals undergoing rehabilitation when walking over various outdoor surfaces and compared them to a standard clinical gait measure. We sought to identify how spatiotemporal aspects of gait change across terrains commonly encountered in the community in individuals undergoing rehabilitation. Forty-six individuals with mobility deficits undergoing outpatient physical therapy completed the 10-meter walk test in clinic and walked over six standardized terrains (e.g., pavers, gravel, sand). We calculated gait speed, cadence, average step length, and walk ratio (calculated as cm\/steps\/min) from video recordings for all conditions and used repeated measures ANOVAs to assess differences between terrains compared to the 10-meter walk test. We then used multiple linear regressions to examine spatiotemporal mechanisms underlying gait speed changes across terrains. Gait speed and cadence were reduced when participants walked over sand, mulch, up sloping gravel, and down sloping gravel compared to the 10-meter walk test. Step length decreased in the sand, gravel upslope, and gravel downslope conditions compared to the 10-meter walk test. Walk ratio was decreased in the sloped gravel conditions. Cadence and step length changes explained 95\u201399% of the variance in gait speed changes across conditions with step length being more heavily weighted across conditions. Individuals undergoing physical therapy for mobility deficits walked slower, with smaller step lengths and cadence when faced with uneven outdoor terrain compared to an indoor 10-meter walk test while walk ratio remained consistent across level surfaces. Speed reductions were related to both step length and cadence. Walk ratio remained consistent across level terrains, indicating a consistent central control strategy, despite terrain changes. Although standardized measures like the 10-meter walk test provide critical information about gait capacity, they may not fully reflect performance in all real-world environments.<\/jats:p>","DOI":"10.1371\/journal.pone.0337177","type":"journal-article","created":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T18:29:42Z","timestamp":1764700182000},"page":"e0337177","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Outdoor ground surface influences spatiotemporal parameters of walking for individuals undergoing rehabilitation: An observational study"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0048-7552","authenticated-orcid":true,"given":"Benjamin S.","family":"Killen","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stacy","family":"Harris","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alan","family":"Levinson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Catherine","family":"Hamilton","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael D.","family":"Lewek","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,12,2]]},"reference":[{"issue":"2","key":"pone.0337177.ref001","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1123\/japa.2013-0236","article-title":"Walking speed: the functional vital sign","volume":"23","author":"A Middleton","year":"2015","journal-title":"J Aging Phys Act"},{"issue":"4","key":"pone.0337177.ref002","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1519\/JPT.0b013e3181ff262c","article-title":"Spatial and temporal parameters of self-selected and fast walking speeds in healthy community-living adults aged 72-98 years","volume":"33","author":"KK Chui","year":"2010","journal-title":"J Geriatr Phys Ther"},{"issue":"2","key":"pone.0337177.ref003","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1519\/00139143-200831020-00003","article-title":"Minimum detectable change in gait velocity during acute rehabilitation following hip fracture","volume":"31","author":"JH Hollman","year":"2008","journal-title":"J Geriatr Phys Ther"},{"issue":"10","key":"pone.0337177.ref004","doi-asserted-by":"crossref","first-page":"1663","DOI":"10.1016\/j.apmr.2011.04.022","article-title":"Normalized muscle strength, aerobic capacity, and walking performance in chronic stroke: a population-based study on the potential for endurance and resistance training","volume":"92","author":"K Severinsen","year":"2011","journal-title":"Arch Phys Med Rehabil"},{"issue":"3","key":"pone.0337177.ref005","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1038\/sc.2009.119","article-title":"Standing balance assessment in ASIA D paraplegic and tetraplegic participants: concurrent validity of the Berg Balance Scale","volume":"48","author":"J-F Lemay","year":"2010","journal-title":"Spinal Cord"},{"issue":"7","key":"pone.0337177.ref006","doi-asserted-by":"crossref","first-page":"670","DOI":"10.1093\/ptj\/82.7.670","article-title":"Environmental demands associated with community mobility in older adults with and without mobility disabilities","volume":"82","author":"A Shumway-Cook","year":"2002","journal-title":"Phys Ther"},{"issue":"7","key":"pone.0337177.ref007","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0182180","article-title":"Older adults must hurry at pedestrian lights! A cross-sectional analysis of preferred and fast walking speed under single- and dual-task conditions","volume":"12","author":"P Eggenberger","year":"2017","journal-title":"PLoS One"},{"issue":"1","key":"pone.0337177.ref008","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1093\/ageing\/26.1.15","article-title":"Comfortable and maximum walking speed of adults aged 20-79 years: reference values and determinants","volume":"26","author":"RW Bohannon","year":"1997","journal-title":"Age Ageing"},{"issue":"6","key":"pone.0337177.ref009","doi-asserted-by":"crossref","first-page":"672","DOI":"10.1177\/1545968308318837","article-title":"Validation of a speed-based classification system using quantitative measures of walking performance poststroke","volume":"22","author":"MG Bowden","year":"2008","journal-title":"Neurorehabil Neural Repair"},{"issue":"2","key":"pone.0337177.ref010","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1161\/STROKEAHA.116.015309","article-title":"Predicting Home and Community Walking Activity Poststroke","volume":"48","author":"GD Fulk","year":"2017","journal-title":"Stroke"},{"issue":"3","key":"pone.0337177.ref011","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1007\/s00221-006-0399-5","article-title":"Adaptations of walking pattern on a compliant surface to regulate dynamic stability","volume":"173","author":"MJ MacLellan","year":"2006","journal-title":"Exp Brain Res"},{"issue":"2","key":"pone.0337177.ref012","first-page":"210","article-title":"Basic gait parameters: reference data for normal subjects, 10-79 years of age","volume":"30","author":"T Oberg","year":"1993","journal-title":"J Rehabil Res Dev"},{"issue":"1","key":"pone.0337177.ref013","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/0966-6362(95)90804-2","article-title":"Voluntary and involuntary adaptation of walking to temporal and spatial constraints","volume":"3","author":"W Zijlstra","year":"1995","journal-title":"Gait & Posture"},{"issue":"4","key":"pone.0337177.ref014","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":"JM Hausdorff","year":"2007","journal-title":"Hum Mov Sci"},{"issue":"1","key":"pone.0337177.ref015","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/s40279-020-01351-3","article-title":"Outdoor Walking Speeds of Apparently Healthy Adults: A Systematic Review and Meta-analysis","volume":"51","author":"EM Murtagh","year":"2021","journal-title":"Sports Med"},{"key":"pone.0337177.ref016","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1016\/j.gaitpost.2021.09.197","article-title":"Walking indoors, outdoors, and on a treadmill: Gait differences in healthy young and older adults","volume":"90","author":"AC Schmitt","year":"2021","journal-title":"Gait Posture"},{"issue":"5","key":"pone.0337177.ref017","doi-asserted-by":"crossref","first-page":"1314","DOI":"10.3390\/s25051314","article-title":"Gait spatio-temporal parameters vary significantly between indoor, outdoor and different surfaces","volume":"25","author":"L Brognara","year":"2025","journal-title":"Sensors (Basel)"},{"issue":"10","key":"pone.0337177.ref018","doi-asserted-by":"crossref","first-page":"105174","DOI":"10.1016\/j.jstrokecerebrovasdis.2020.105174","article-title":"Does the Environment Cause Changes in Hemiparetic Lower Limb Muscle Activity and Gait Velocity During Walking in Stroke Survivors?","volume":"29","author":"J D\u2019souza","year":"2020","journal-title":"J Stroke Cerebrovasc Dis"},{"issue":"2","key":"pone.0337177.ref019","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.gaitpost.2011.04.006","article-title":"Central gait control mechanisms and the stride length - cadence relationship","volume":"34","author":"T Egerton","year":"2011","journal-title":"Gait Posture"},{"key":"pone.0337177.ref020","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/j.gaitpost.2018.02.019","article-title":"The walk ratio: Investigation of invariance across walking conditions and gender in community-dwelling older people","volume":"61","author":"B Bogen","year":"2018","journal-title":"Gait Posture"},{"key":"pone.0337177.ref021","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.gaitpost.2018.08.030","article-title":"Association of walk ratio during normal gait speed and fall in community-dwelling elderly people","volume":"66","author":"S Nakakubo","year":"2018","journal-title":"Gait Posture"},{"key":"pone.0337177.ref022","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.gaitpost.2020.09.030","article-title":"Analysis of sloped gait: How many steps are needed to reach steady-state walking speed after gait initiation?","volume":"83","author":"G Strutzenberger","year":"2021","journal-title":"Gait Posture"},{"issue":"6","key":"pone.0337177.ref023","doi-asserted-by":"crossref","first-page":"733","DOI":"10.2522\/ptj.20070214","article-title":"Test-retest reliability and minimal detectable change on balance and ambulation tests, the 36-item short-form health survey, and the unified Parkinson disease rating scale in people with parkinsonism","volume":"88","author":"T Steffen","year":"2008","journal-title":"Phys Ther"},{"issue":"7","key":"pone.0337177.ref024","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1191\/0269215503cr677oa","article-title":"Inter-rater reliability and concurrent validity of walking speed measurement after traumatic brain injury","volume":"17","author":"MA van Loo","year":"2003","journal-title":"Clin Rehabil"},{"issue":"12","key":"pone.0337177.ref025","doi-asserted-by":"crossref","first-page":"1122","DOI":"10.1093\/ptj\/79.12.1122","article-title":"Establishing the reliability and validity of measurements of walking time using the Emory Functional Ambulation Profile","volume":"79","author":"SL Wolf","year":"1999","journal-title":"Phys Ther"},{"issue":"11","key":"pone.0337177.ref026","doi-asserted-by":"crossref","first-page":"2146","DOI":"10.1016\/j.apmr.2008.04.016","article-title":"Performance-based or self-report measures of physical function: which should be used in clinical trials of hip fracture patients?","volume":"89","author":"NK Latham","year":"2008","journal-title":"Arch Phys Med Rehabil"},{"issue":"3","key":"pone.0337177.ref027","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1097\/NPT.0000000000000229","article-title":"A Core Set of Outcome Measures for Adults With Neurologic Conditions Undergoing Rehabilitation: a clinical practice guideline","volume":"42","author":"JL Moore","year":"2018","journal-title":"J Neurol Phys Ther"},{"issue":"1","key":"pone.0337177.ref028","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1519\/JPT.0b013e318248e20d","article-title":"Assessing the reliability and validity of a shorter walk test compared with the 10-Meter Walk Test for measurements of gait speed in healthy, older adults","volume":"36","author":"DM Peters","year":"2013","journal-title":"J Geriatr Phys Ther"},{"issue":"3","key":"pone.0337177.ref029","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/S0031-9406(05)67156-8","article-title":"Temporal Gait Analysis Using Slow Motion Video and a Personal Computer","volume":"83","author":"JC Wall","year":"1997","journal-title":"Physiotherapy"},{"issue":"4","key":"pone.0337177.ref030","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1177\/0309364620921290","article-title":"Two-dimensional video gait analysis: A systematic review of reliability, validity, and best practice considerations","volume":"44","author":"A Michelini","year":"2020","journal-title":"Prosthet Orthot Int"},{"key":"pone.0337177.ref031","volume-title":"R: A Language and Environment for Statistical Computing","author":"R Core Team","year":"2024"},{"key":"pone.0337177.ref032","unstructured":"Kassambara A. rstatix: Pipe-Friendly Framework for Basic Statistical Tests. 2023."},{"key":"pone.0337177.ref033","volume-title":"Statistical power analysis for the behavioral sciences","author":"J Cohen","year":"1988","edition":"2"},{"key":"pone.0337177.ref034","volume-title":"An R Companion to Applied Regression","author":"J Fox","year":"2019"},{"key":"pone.0337177.ref035","doi-asserted-by":"crossref","first-page":"23337214211048955","DOI":"10.1177\/23337214211048955","article-title":"Standard error of the mean and minimal detectable change of gait speed in older adults using japanese long-term care insurance system","volume":"7","author":"Y Takada","year":"2021","journal-title":"Gerontol Geriatr Med"},{"issue":"2","key":"pone.0337177.ref036","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1097\/NPT.0000000000000257","article-title":"Minimal detectable change for gait speed depends on baseline speed in individuals with chronic stroke","volume":"43","author":"MD Lewek","year":"2019","journal-title":"J Neurol Phys Ther"},{"issue":"4","key":"pone.0337177.ref037","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1519\/JPT.0000000000000068","article-title":"Test-retest reliability and minimal detectable change for the 10-meter walk test in older adults with parkinson\u2019s disease","volume":"39","author":"JT Lang","year":"2016","journal-title":"J Geriatr Phys Ther"},{"issue":"5","key":"pone.0337177.ref038","doi-asserted-by":"crossref","first-page":"1298","DOI":"10.1183\/09031936.00088113","article-title":"The 4-metre gait speed in COPD: responsiveness and minimal clinically important difference","volume":"43","author":"SSC Kon","year":"2014","journal-title":"Eur Respir J"},{"key":"pone.0337177.ref039","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.gaitpost.2021.06.001","article-title":"Minimal clinically important difference in walking velocity, gait profile score and two minute walk test for individuals with lower limb amputation","volume":"88","author":"B Carse","year":"2021","journal-title":"Gait Posture"},{"issue":"6","key":"pone.0337177.ref040","doi-asserted-by":"crossref","first-page":"809","DOI":"10.1093\/ptj\/86.6.809","article-title":"Determining meaningful changes in gait speed after hip fracture","volume":"86","author":"KM Palombaro","year":"2006","journal-title":"Phys Ther"},{"issue":"4","key":"pone.0337177.ref041","doi-asserted-by":"crossref","first-page":"246","DOI":"10.1038\/sj.sc.3102134","article-title":"A systematic review of functional ambulation outcome measures in spinal cord injury","volume":"46","author":"T Lam","year":"2008","journal-title":"Spinal Cord"},{"issue":"2","key":"pone.0337177.ref042","doi-asserted-by":"crossref","first-page":"176","DOI":"10.2522\/ptj.20070064","article-title":"Measuring deterioration in international classification of functioning domains of people with multiple sclerosis who are ambulatory","volume":"88","author":"J Paltamaa","year":"2008","journal-title":"Phys Ther"},{"issue":"3","key":"pone.0337177.ref043","first-page":"179","article-title":"Gait analysis of slope walking: a study on step length, stride width, time factors and deviation in the center of pressure","volume":"45","author":"K Kawamura","year":"1991","journal-title":"Acta Med Okayama"},{"issue":"4","key":"pone.0337177.ref044","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1080\/00140139608964489","article-title":"The influence of surface slope on human gait characteristics: a study of urban pedestrians walking on an inclined surface","volume":"39","author":"J Sun","year":"1996","journal-title":"Ergonomics"},{"issue":"1","key":"pone.0337177.ref045","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1519\/JPT.0b013e3182510339","article-title":"Effects of an inclined walking surface and balance abilities on spatiotemporal gait parameters of older adults","volume":"36","author":"RA Ferraro","year":"2013","journal-title":"J Geriatr Phys Ther"},{"issue":"5","key":"pone.0337177.ref046","doi-asserted-by":"crossref","first-page":"416","DOI":"10.1177\/1545968314552528","article-title":"Walking speed and step length asymmetry modify the energy cost of walking after stroke","volume":"29","author":"LN Awad","year":"2015","journal-title":"Neurorehabil Neural Repair"},{"issue":"12","key":"pone.0337177.ref047","article-title":"Steps to take to enhance gait stability: the effect of stride frequency, stride length, and walking speed on local dynamic stability and margins of stability","volume":"8","author":"L Hak","year":"2013","journal-title":"PLoS One"},{"key":"pone.0337177.ref048","doi-asserted-by":"crossref","first-page":"106316","DOI":"10.1016\/j.clinbiomech.2024.106316","article-title":"Dynamic gait stability in people with mild to moderate Parkinson\u2019s disease","volume":"118","author":"R Ban","year":"2024","journal-title":"Clin Biomech (Bristol)"},{"issue":"3","key":"pone.0337177.ref049","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1016\/j.gaitpost.2010.06.013","article-title":"Independent influence of gait speed and step length on stability and fall risk","volume":"32","author":"DD Espy","year":"2010","journal-title":"Gait Posture"},{"key":"pone.0337177.ref050","doi-asserted-by":"crossref","first-page":"105766","DOI":"10.1016\/j.clinbiomech.2022.105766","article-title":"Regulation of whole-body and segmental angular momentum in persons with Parkinson\u2019s disease on an irregular surface","volume":"99","author":"NG Gomez","year":"2022","journal-title":"Clin Biomech (Bristol)"},{"key":"pone.0337177.ref051","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":"P Ippersiel","year":"2021","journal-title":"Gait Posture"},{"key":"pone.0337177.ref052","first-page":"3963","article-title":"Biomechanics and energetics of walking on uneven terrain","volume":"216","author":"AS Voloshina","year":"2013","journal-title":"J Exp Biol"},{"issue":"1","key":"pone.0337177.ref053","doi-asserted-by":"crossref","first-page":"17664","DOI":"10.1038\/s41598-019-54050-z","article-title":"Changes in human walking dynamics induced by uneven terrain are reduced with ongoing exposure, but a higher variability persists","volume":"9","author":"JA Kent","year":"2019","journal-title":"Sci Rep"},{"key":"pone.0337177.ref054","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/j.gaitpost.2023.05.022","article-title":"Characteristics of uneven surface walking in stroke patients: Modification in biomechanical parameters and muscle activity","volume":"103","author":"Y Inui","year":"2023","journal-title":"Gait Posture"},{"key":"pone.0337177.ref055","doi-asserted-by":"crossref","first-page":"109602","DOI":"10.1016\/j.jbiomech.2020.109602","article-title":"Effect of investigator observation on gait parameters in individuals with stroke","volume":"100","author":"MM Ardestani","year":"2020","journal-title":"J Biomech"},{"issue":"12","key":"pone.0337177.ref056","doi-asserted-by":"crossref","first-page":"1648","DOI":"10.1016\/j.apmr.2006.09.012","article-title":"Agreement between the GAITRite walkway system and a stopwatch-footfall count method for measurement of temporal and spatial gait parameters","volume":"87","author":"JW Youdas","year":"2006","journal-title":"Arch Phys Med Rehabil"},{"issue":"6","key":"pone.0337177.ref057","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1016\/j.pmrj.2010.02.008","article-title":"Responsiveness of 2 procedures for measurement of temporal and spatial gait parameters in older adults","volume":"2","author":"JW Youdas","year":"2010","journal-title":"PM R"},{"key":"pone.0337177.ref058","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.clinbiomech.2018.06.013","article-title":"Gait alterations on irregular surface in people with Parkinson\u2019s disease","volume":"57","author":"H Xu","year":"2018","journal-title":"Clin Biomech (Bristol)"},{"issue":"14","key":"pone.0337177.ref059","doi-asserted-by":"crossref","first-page":"4792","DOI":"10.3390\/s21144792","article-title":"Gait variability and complexity during single and dual-task walking on different surfaces in outdoor environment","volume":"21","author":"D Nohelova","year":"2021","journal-title":"Sensors (Basel)"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0337177","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T18:29:50Z","timestamp":1764700190000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0337177"}},"subtitle":[],"editor":[{"given":"Yih-Kuen","family":"Jan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,12,2]]},"references-count":59,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,12,2]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0337177","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,2]]}}}