Validity and Reliability of a Mixed Reality-Based 6-Minute Walk Test

Official title

Validity and Reliability of a Mixed Reality-Based Adaptation of the 6-Minute Walk Test in Asymptomatic Adults

Overview

The 6-Minute Walk Test (6MWT) is a widely used field test for assessing functional exercise capacity, walking endurance, and submaximal performance related to activities of daily living. However, in conventional applications, environmental conditions, observer-related differences, and standardization issues may lead to variability in measurement outcomes. In addition, evaluating only the total walking distance may not adequately reflect clinically important changes such as performance decline and walking-related motor fatigue occurring during the test. For this reason, recent studies have recommended analyzing 6MWT data by dividing the test into minute-by-minute segments and using performance change metrics such as the Distance Walked Index (DWI). These approaches allow a more detailed evaluation of changes in walking performance throughout the test duration. With advances in measurement technologies, mixed reality (MR)-based applications have attracted attention as a means of enabling more objective, standardized, and reproducible implementation of conventional clinical tests. MR technology allows users to maintain interaction with the real environment while receiving digital guidance and feedback, thereby providing a safe and standardized assessment setting. Nevertheless, evidence regarding the validity and reliability of mixed reality-based adaptations of the 6MWT, particularly in asymptomatic adults, remains limited. The aim of this study is to evaluate the criterion validity and test-retest reliability of a mixed reality-based 6-Minute Walk Test (MR-6MWT) developed using the Meta Quest 3 and Unity platform. In addition, convergent validity will be examined by analyzing the relationships between total walking distance, minute-by-minute performance changes, fatigue effect (%), and outcomes of the 4-Meter Walk Test, Timed Up and Go Test, and knee extensor muscle strength. The findings of this study are expected to contribute to the development of a more objective, standardized, and digitally based mixed reality adaptation of the 6MWT. Furthermore, the results may provide a scientific foundation for future remote assessment and digital monitoring applications.

Interventions

• Other Mixed Reality-Based 6-Minute Walk Test Assessment
  Participants will perform a mixed reality-based adaptation of the 6-Minute Walk Test (MR-6MWT) developed using the Meta Quest 3 headset and Unity platform. The mixed reality environment provides standardized visual guidance and virtual markers while allowing participants to safely walk in the real environment. During both conventional and MR-based assessments, walking distance, physiological responses, perceived exertion, and fatigue-related performance changes will be recorded. The MR-6MWT will

Primary outcome measures

• 6-Minute Walk Distance - Mixed Reality (MR-6MWT) [Time frame: Baseline and 1-week follow-up]
• Fatigue Effect During the Mixed Reality-Based 6-Minute Walk Test [Time frame: Baseline and 1-week follow-up]

Secondary outcome measures (6)

• 6-Minute Walk Distance - Conventional 6-Minute Walk Test [Time frame: Baseline]
• Fatigue Effect During the Conventional 6-Minute Walk Test [Time frame: Baseline]
• Timed Up and Go Test (TUG) [Time frame: Baseline]
• 4-Meter Walk Test (4MWT) [Time frame: Baseline]
• Knee Extensor Muscle Strength [Time frame: Baseline]
• Participant Satisfaction [Time frame: Baseline]

Eligibility criteria

Inclusion criteria

• Aged between 18 and 65 years,
• Asymptomatic, with no known or active cardiopulmonary, neurological, or musculoskeletal disease-related symptoms,
• Ability to ambulate independently without the use of an assistive device,
• Visual, auditory, and vestibular functions sufficient to tolerate mixed reality applications,
• Cognitive ability sufficient to understand and follow test instructions,
• Ability to read, understand, and follow instructions in Turkish,
• Willingness to participate voluntarily in the study and provision of written informed consent.

Exclusion criteria

• Inability to safely complete walking tests due to serious musculoskeletal conditions (e.g., recent fracture, severe arthritis, advanced osteoarthritis, significant muscle or tendon injury),
• Presence of severe cardiopulmonary disease or any medical condition that may pose a risk during exercise testing (e.g., uncontrolled hypertension, heart failure, severe arrhythmia history, chronic obstructive pulmonary disease),
• High risk of balance loss or spatial disorientation in the mixed reality environment due to vestibular, visual, or auditory impairments,
• History of epilepsy or neurological conditions contraindicating mixed reality or head-mounted device use,
• Severe migraine, significant motion sickness history, or high risk of dizziness/nausea during mixed reality applications,
• Cognitive impairment or severe psychiatric conditions preventing understanding or completion of test procedures,
• Insufficient motivation or cooperation that may interfere with safe participation in the study.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model

Other

Study locations

Turkey (Türkiye) · 1 center

• Selcuk University, Faculty of Health Sciences, Department of Physiotherapy and Rehabilitat — Konya

Publications

• Van Geel F, Veldkamp R, Severijns D, Dalgas U, Feys P. Day-to-day reliability, agreement and discriminative validity of measuring walking-related performance fatigability in persons with multiple sclerosis. Mult Scler. 2020 Nov;26(13):1785-1789. doi: 10.1177/1352458519872465. Epub 2019 Sep 9. PMID 31496362
• Ramari C, Hvid LG, David AC, Dalgas U. The importance of lower-extremity muscle strength for lower-limb functional capacity in multiple sclerosis: Systematic review. Ann Phys Rehabil Med. 2020 Mar;63(2):123-137. doi: 10.1016/j.rehab.2019.11.005. Epub 2019 Dec 6. PMID 31816449
• Maden C, Gozacan Karabulut D, Bagci B. Validity and reliability of an immersive virtual reality adaptation of the 6-minute pegboard and ring test. Hand Surg Rehabil. 2025 Feb;44(1):101981. doi: 10.1016/j.hansur.2024.101981. Epub 2024 Oct 30. PMID 39486588
• Leone C, Severijns D, Dolezalova V, Baert I, Dalgas U, Romberg A, Bethoux F, Gebara B, Santoyo Medina C, Maamagi H, Rasova K, Maertens de Noordhout B, Knuts K, Skjerbaek A, Jensen E, Wagner JM, Feys P. Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis: Decline in Walking Distance Induced by the 6-Minute Walk Test. Neurorehabil Neural Repair. 2016 May;30(4):373-83. doi: PMID 26216790
• Hwang R, Morris NR, Mandrusiak A, Mudge A, Suna J, Adsett J, Russell T. Timed Up and Go Test: A Reliable and Valid Test in Patients With Chronic Heart Failure. J Card Fail. 2016 Aug;22(8):646-50. doi: 10.1016/j.cardfail.2015.09.018. Epub 2015 Oct 9. PMID 26456063
• Grimpampi E, Oesen S, Halper B, Hofmann M, Wessner B, Mazza C. Reliability of gait variability assessment in older individuals during a six-minute walk test. J Biomech. 2015 Nov 26;48(15):4185-4189. doi: 10.1016/j.jbiomech.2015.10.008. Epub 2015 Oct 20. PMID 26515246
• Gautschi OP, Smoll NR, Corniola MV, Joswig H, Chau I, Hildebrandt G, Schaller K, Stienen MN. Validity and Reliability of a Measurement of Objective Functional Impairment in Lumbar Degenerative Disc Disease: The Timed Up and Go (TUG) Test. Neurosurgery. 2016 Aug;79(2):270-8. doi: 10.1227/NEU.0000000000001195. PMID 26702840
• ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med. 2002 Jul 1;166(1):111-7. doi: 10.1164/ajrccm.166.1.at1102. No abstract available. PMID 12091180

Identifiers

NCT: NCT07601009 · SelcukU_PT_6MWT_MR_ADAPTATION

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗