The effect of treadmill walking on the stride interval dynamics of children

Treadmills are commonly implemented in rehabilitation and laboratory settings to facilitate gait analysis and training. However, while this locomotor modality is often used with children, its effect on pediatric stride interval dynamics is unknown. This study investigated the stride interval persistence of 30 asymptomatic children after completion of three to six 10-min walking trials comprised of: (i) overground walking (OW), (ii) unsupported treadmill walking (UTW), and (iii) handrail-supported treadmill walking (STW). The primary outcome measure was αα, a quantifier of stride interval persistence obtained from detrended fluctuation analysis. Preferred walking speed, number of strides taken, stride interval duration, and stride interval coefficient of variation were also assessed. Stride interval persistence was significantly diminished during both treadmill walking conditions, compared to overground walking, with the largest decrease in αα during UTW. Preferred speed, number of strides, and stride interval duration also differed between overground and treadmill walking, and older children demonstrated reduced stride interval variability compared to younger children. The observed treadmill and age effects on stride parameters may be due to a combination of differing locomotor constraints between overground and treadmill walking and developmental differences in sensory processing, cerebellar plasticity, and corticospinal involvement in locomotion.