Indoor and outdoor 10-Meter Walk Test and Timed Up and Go in patients after total hip arthroplasty: a reliability and comparative study

Abstract

Introduction: The 10-Meter Walk Test (10MWT) and Timed Up and Go (TUG) are valid tools for gait performance and mobility assessment after total hip arthroplasty (THA). The study aimed to assess test-retest reliability of 10MWT and TUG in indoor and outdoor environments in patients in acute phase after THA and compare their indoor vs. outdoor performance during these tests. Methods: Thirty-five inpatients performed 10MWT and TUG in indoor and outdoor settings on the second postoperative day. An additional evaluation session was performed after 1 hour under the supervision of the same operator. Test-retest reliability was assessed using Intraclass Correlation Coefficient (ICC: 2.1) and Minimal Detectable Change (MDC95), while paired t-tests were used to compare indoor vs. outdoor performance. Results: Indoor (ICC: 0.94, MDC95: 0.13 m/s) and outdoor (ICC: 0.91, MDC95: 0.16 m/s) 10MWT at maximum speed and indoor (ICC: 0.92, MDC95: 2.5 s) and outdoor (ICC: 0.93, MDC95: 2.4 s) TUG revealed excellent reliability. Indoor (ICC: 0.86, MDC95: 0.16 m/s) and outdoor (ICC: 0.89, MDC95: 0.16 m/s) 10MWT at spontaneous speed revealed good reliability. Spontaneous (mean difference [MD]: 0.05 m/s, 95% confidence interval [CI95]: 0.03, 0.07, p < 0.001) and maximum (MD: 0.02 m/s, CI95: 0.01, 0.04, p < 0.001) 10MWT revealed higher gait speed when performed outdoors compared to indoors. Conclusions: Indoor and outdoor 10MWT and TUG are reliable tests in acute phase after THA. Higher gait speed during outdoor 10MWT may depend on test score variability, due to MDs being lower than MDC95.