Psychometric properties of 3-meter backward walk test (3MBWT) in people with Parkinson disease

• Published in: Physiotherapy theory and practice Vol. 41; no. 3; pp. 656 - 663
• Main Authors: Barta, Kristen, Boddy, Anne Hill, Flores, Megan, Perry, Lindsay, Sawyer, Kathryn, Campbell, Ashley
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Ltd 01.03.2025
• Subjects: Aged; Computerization; Disability Evaluation; Female; Gait; Humans; Interrater reliability; Male; Middle Aged; Observer Variation; Parkinson Disease - diagnosis; Parkinson Disease - physiopathology; Parkinson Disease - psychology; Parkinson's disease; Predictive Value of Tests; Psychometrics; Quantitative psychology; Reproducibility of Results; Tests; Validity; Velocity; Walk Test - methods; Walking; Walking Speed; Walkways; 3-meter backward walk test; Parkinson’s disease; gait velocity; backward walking
• ISSN: 0959-3985; 1532-5040; 1532-5040
• DOI: 10.1080/09593985.2024.2348034

The purpose of this study was to investigate the 3-meter backward walk test (3MBWT) in individuals with Parkinson Disease (PD) to determine the following: (1) concurrent validity with other gait velocity measures and (2) interrater and intrarater reliability of in-person and video assessment. A convenience sample of 25 people with PD participated. Forward gait velocity was measured using a computerized walkway (Zeno Walkway System), the 10-meter walk test (10MWT), and 4-meter walk test (4MWT). Backward gait velocity was measured using the 3MBWT. Concurrent validity was assessed using Pearson's correlations. Reliability was assessed using intra-class correlation coefficients (ICC ). All relationships between the 3MBWT and gait outcome measures were significant. The 3MBWT demonstrated strong correlations with the 4MWT dual task (  = .795, =<.001) and moderate correlations with 4MWT comfortable walking speed (  = .658,  < .001), 4MWT fast walking speed (  = .601, =.002), 10MWT comfortable walking speed (  = .512,  = .009), and 10MWT dual task (  = .535,  = .006). A low yet significant correlation was noted with the 10MWT fast walking speed (  = .398,  = .049). Association between the 3MBWT and the Zeno Walkway System revealed moderate correlations. All reliability tests were significant at  < .001. Interrater reliability ICC values were very high for 3MBWT (ICC  = 0.93, [0.83-0.91]). Intrarater reliability was also very high (ICC  = 0.96 [0.90-0.98]). The 3MBWT demonstrates validity and reliability as a tool for assessing gait speed in the posterior direction in people with PD.