Uneven terrain treadmill walking in younger and older adults

Abstract

We developed a method for altering terrain unevenness on a treadmill to study gait kinematics. Terrain consisted of rigid polyurethane disks (12.7 cm diameter, 1.3–3.8 cm tall) which attached to the treadmill belt using hook-and-loop fasteners. Here, we tested four terrain unevenness conditions: Flat, Low, Medium, and High. The main objective was to test the hypothesis that increasing the unevenness of the terrain would result in greater gait kinematic variability. Seventeen younger adults (age 20–40 years), 25 higher-functioning older adults (age 65+ years), and 29 lower-functioning older adults (age 65+ years, Short Physical Performance Battery score < 10) participated. We customized the treadmill speed to each participant’s walking ability, keeping the speed constant across all four terrain conditions. Participants completed two 3-minute walking trials per condition. Using an inertial measurement unit placed over the sacrum and pressure sensors in the shoes, we calculated the stride-to-stride variability in step duration and sacral excursion (coefficient of variation; standard deviation expressed as percentage of the mean). Participants also self-reported their perceived stability for each condition. Terrain was a significant predictor of step duration variability, which roughly doubled from Flat to High terrain for all participant groups: younger adults (Flat 4.0%, High 8.2%), higher-functioning older adults (Flat 5.0%, High 8.9%), lower-functioning older adults (Flat 7.0%, High 14.1%). Similarly, all groups exhibited significant increases in sacral excursion variability for the Medium and High uneven terrain conditions, compared to Flat. Participants were also significantly more likely to report feeling less stable walking over all three uneven terrain conditions compared to Flat. These findings support the hypothesis that altering terrain unevenness on a treadmill will increase gait kinematic variability and reduce perceived stability in younger and older adults.

Uneven terrain versus dual-task walking: differential challenges imposed on walking behavior in older adults are predicted by cognitive and sensorimotor function

“…It is possible that the difficulty of the cursor tracking task did not reach a demand level where older adults failed to compensate for age-related declines. In recent work by our team (Downey et al, 2022), young adults and a subset of the older adults from this study performed uneven terrain walking on a treadmill, which resulted in greater perceived walking instability and increased gait variability in older adults as terrain unevenness was parametrically increased. Our team plans to extend the work of Downey and colleagues in future analyses of data collected within the Mind in Motion study (Clark et al, 2020).…”

“…Compared to dual-task paradigms, an approach that examines walking ability through uneven terrains may better mimic walking environments where fall incidents are prevalent, and therefore have greater ecological relevance. Previous studies have manipulated walking task difficulty by changing path width, adding obstacles, or with uneven terrains/surfaces in the walking path (Chatterjee et al, 2020; Darici & Kuo, 2022; Downey et al, 2022; Kotegawa et al, 2021; Marigold & Patla, 2008a, 2008b; Voloshina et al, 2013). Marigold and Patla (2008a) investigated the role of vision and age differences in gait speed and step length and width during multi-surface terrain walking.…”

Comparison of EEG Source Localization Using Simplified and Anatomically Accurate Head Models in Younger and Older Adults

“…The order of the trials was randomized. Details of the study design were reported in the previous papers [ 41 ] and [ 43 ]. Participants completed two trials per condition, and each trial lasted for 3 minutes.…”

iCanClean Improves Independent Component Analysis of Mobile Brain Imaging with EEG

“…We collected mobile high-density EEG data from human participants walking over flat and uneven terrain on a custom treadmill [ 29 ], as depicted in Figure 2 a. The data were collected as part of a larger study called Mind in Motion [ 30 ].…”