Investigating the correlation between paediatric stride interval persistence and gross energy expenditure

Abstract

BackgroundStride interval persistence, a term used to describe the correlation structure of stride interval time series, is thought to provide insight into neuromotor control, though its exact clinical meaning has not yet been realized. Since human locomotion is shaped by energy efficient movements, it has been hypothesized that stride interval dynamics and energy expenditure may be inherently tied, both having demonstrated similar sensitivities to age, disease, and pace-constrained walking.FindingsThis study tested for correlations between stride interval persistence and measures of energy expenditure including mass-specific gross oxygen consumption per minute (), mass-specific gross oxygen cost per meter (VO2) and heart rate (HR). Metabolic and stride interval data were collected from 30 asymptomatic children who completed one 10-minute walking trial under each of the following conditions: (i) overground walking, (ii) hands-free treadmill walking, and (iii) handrail-supported treadmill walking. Stride interval persistence was not significantly correlated with (p > 0.32), VO2 (p > 0.18) or HR (p > 0.56).ConclusionsNo simple linear dependence exists between stride interval persistence and measures of gross energy expenditure in asymptomatic children when walking overground and on a treadmill.

A Pediatric Correlational Study of Stride Interval Dynamics, Energy Expenditure and Activity Level

“…The lack of correlation found between  and the physiological cost of walking is consistent with that of previous studies in younger children [10] and the elderly [27]. This finding could be partially attributed to the relatively small data set, though participants exhibited a range of energy cost and  values similar to those of other studies [9,10,16].…”

“…To date, only two studies have examined α and the energy cost of walking. Most recently, an investigation of SI dynamics in children aged 4-7 years identified no correlation between  and Pediatric SI Dynamics, Energy & Activity 5 energy cost [10]. However, this study only examined the gross energy cost of walking, which represents the total cost of walking inclusive of resting cost [32].…”

“…From the extracted stride intervals, strides that fell outside 0.01% and 99.99% of a gamma distribution fit were eliminated. These strides were considered as unphysiologically long or short and were likely due to occasional sensor noise [10]. To minimize 'start up' and 'end' effects, 30 seconds of data were trimmed from the beginning and the end of each time series.…”

“…The present study aimed to develop a better understanding of the relationship between the strength of statistical persistence, the net energy cost of walking and activity levels in typically Pediatric SI Dynamics, Energy & Activity 6 developing children, 9-15 years, an age at which gait is considered mature [9,22]. A defined relationship between  and physical activity could also provide insight into the physiological mechanisms responsible for stride interval persistence, which to date remain unclear [10]. The energetic cost of walking was estimated using the Cosmed K4b 2 (Cosmed, Italy), a portable gas analysis system that measures oxygen consumption and carbon dioxide production on a Pediatric SI Dynamics, Energy & Activity 7…”

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

“…Data from one subject was discarded due to technical difficulties with gas exchange measurement, which is part of a secondary investigation reported elsewhere (Fairley et al, 2009b). Of the remaining 30 children (11 male) forming the sample for this analysis, mean age was 7.1 ± 1.6 years (range: 4-10 years), height was 1.249 ± 0.115 m and body mass was 24.1 ± 4.9 kg.…”