Author(s): RAIMO, M., PAPINI, G.B., GUERRA, G., BERTOLLO, M., SARTOR, F., Institution: UNIVERSITY OF MOLISE, Country: ITALY, Abstract-ID: 511

INTRODUCTION:
The 6-Minute Walk Test (6MWT) is commonly used to assess cardiorespiratory functional capacity in healthy1 and clinical populations. However, its interpretation concerning movement information typically relies solely on total distance covered, providing little information about locomotor and pacing strategies. Although changes in walking patterns (e.g., step frequency and amplitude) are known to be related to the onset of fatigue, these alterations are not captured in the 6MWT evaluation. Thus, this study aimed to quantify within‑ and between‑subject variability in walking patterns throughout the 6MWT.
METHODS:
Thirty-two apparently healthy participants (age = 28 ± 8.93, BMI = 24.83 ± 4.15) completed a 6MWT while wearing an ankle accelerometer (tri-axial, 100 Hz, GT3X, ActiGraph). The test was conducted on a 30-meter course marked at 5 and 25 meters. Thus, 20-meter segments were recorded as participants crossed both marks. The first segment served as an individualized reference template, which was compared with the subsequent segments. Time and frequency domain gait features such as amplitude, energy, step frequency, and morphological similarity metrics were computed for each segment. Within‑ and between‑subject variability was quantified using coefficients of variation (CoV) and intraclass correlation coefficients (ICC) with 95% confidence intervals (RStudio 2025.09.2+418).
RESULTS:
Within-subject variability across all segments ranged between 2.8 to 5.6% CoV and ranged from 0.61 to 0.93 ICC. Step amplitude and energy showed the highest stability (ICC > 0.90). While step frequency had the highest variability (ICC: 0.61-0.72), possibly reflecting pacing adjustments. As expected, between‑subject variability was larger than within variability (6.1-21.2% CoV), with step frequency exhibiting the greatest inter‑individual variability (21.2%).
CONCLUSION:
Six minutes of standardized walking are sufficient to reveal meaningful within‑subject variability in frequency‑related gait features. These intra‑ and inter‑individual gait differences remain underexplored, yet they may offer valuable insights into locomotor control and cardiorespiratory fitness beyond total distance walked.

References
1- Albergoni A, Hettinga FJ, Stut W, Sartor F. Factors Influencing Walking and Exercise Adherence in Healthy Older Adults Using Monitoring and Interfacing Technology: Preliminary Evidence. Int J Environ Res Public Health. 2020 Aug 24;17(17):6142. doi: 10.3390/ijerph17176142. PMID: 32846988; PMCID: PMC7503601.