Qualitative study of the association between psychosocial health and physical activity/sleep quality in toddlers.

Physical activity and sleep are important factors of mental and physical health in children, with some reports indicating that their effects can persist into adulthood. However, there is limited research on the qualitative aspects of physical activity and sleep in preschool children, particularly in those aged < 3 years. Therefore, to elucidate the association between psychosocial health and physical activity/sleep in early childhood in terms of qualitative aspects, we conducted a retrospective cohort study in 2985 3-year-old children (37.2 ± 0.75 months) in Shanghai, China. An analysis using structural equation modeling indicated that current physical activity had a direct and moderate impact on current psychosocial health evaluated using the Strength and Difficulties Questionnaire. In particular, past physical activity had an indirect and mild effect on current psychosocial health via current physical activity in girls. However, regardless of sex, past sleep quality had slight impact on current psychosocial health, not only indirectly via current sleep quality, but also directly. These findings highlight the importance of considering the qualitative aspects of physical activity and sleep quality as significant factors influencing the current and future psychosocial health of children, even at a very early age (< 3 years).

Association between daily gait speed patterns and cognitive impairment in community-dwelling older adults.

Gait speed over a short distance is associated with cognitive impairment in older adults. Recently, daily gait speed has been assessed using accelerometers. However, because daily gait speed is only weakly correlation with gait speed over a short distance, its association with cognitive impairment needs to be investigated. The present study compared the daily gait speed patterns of normal cognition (NC), mild cognitive impairment (MCI), and general cognitive impairment (GCI) subjects measured every 3 h for two weeks using accelerometers. A total of 1959 participants were classified into the NC (N = 1519), MCI (N = 353), and GCI groups (N = 87). The results showed that the average daily gait speed of the GCI group was significantly lower than that of the NC group (p = 0.03). Furthermore, the average daily gait speeds of the MCI and NC groups were the same. However, the average daily gait speed of the MCI group during a specific time (12-15 o'clock) was significantly lower than that of the NC group (p < 0.01). These results suggest that changes in daily patterns may be detected by measuring daily gait speed, which depends on the degree of cognitive function.

Estimability study on the age of toddlers' gait development based on gait parameters.

In the first few years of toddlers' locomotion, various gait parameters improve gradually and dynamically with gait development. Therefore, in this study, we hypothesized that the age of gait development, or the level of gait development with age as its indicator, can be estimated from several gait parameters related to gait development, and investigated its estimability. In total, 97 healthy toddlers aged about 1-3 years participated in the study. All five selected gait parameters showed a moderate or higher correlation with age, but the duration with a large change and the strength of the association with gait development varied for each gait parameter. Multiple regression analysis was performed using age as the objective variable and five selected gait parameters as explanatory variables, and an estimation model (R2 = 0.683, adjusted R2 = 0.665) was created. The estimation model was verified using a test dataset separate from the training dataset (R2 = 0.82, p < 0.001). It was suggested that the age of gait development could be estimated from gait alone. Gait analysis based on empirical observations may reduce the need for skilled observers and their potential variability.

Effect of wearing diapers on toddler's gait.

Gait maturation in infants develops gradually through several phases. However, external factors such as childrearing practices, especially the wearing of diapers, may affect an infant's motor development. This study investigated the influence of different bulk stresses on the gait of toddlers wearing a disposable diaper. Twenty-six healthy toddlers (age: 19.2 ± 0.9 months) participated in this study. We measured the joint kinematics (pelvis angle and hip-joint angle) and spatiotemporal parameters (step length and step width) of the toddlers' gait under four dress conditions (wearing Type A_WET, Type A_DRY, and Type B_WET diapers and naked). Type B_WET had a higher bulk stress than Type A_WET, and Type A_DRY had lower stress than Type A _ WET. Our results indicate that the walk of toddlers when wearing a diaper differs from that when naked. This difference is due to the effect of the bulk of the diaper on the lower limb. A high bulk stress has a greater influence than that of a low bulk stress on joint dynamics and step width. Therefore, our findings suggest that wearing diapers with high bulk stress may inhibit the natural gait patterns of toddlers.

Classification and kinetic analysis of viscosity growth processes for NaOH-gelatinized rice starches.

Using capillary viscometry, viscosity growth processes were studied for non-glutinous rice starches gelatinized with different NaOH solution concentrations. The viscosity-time data series generally conformed to sigmoid curves with an arbitrary inflection point (IP) for each curve, and were analyzed using a kinetic model that incorporated a first-order reaction rate equation and a mixing rule of a power-law type. The shapes of curves were classified with the exponent ν or the ratio η(*)/ηG, where η(*) and ηG were viscosities at IP and at equilibrium, respectively. It was argued that these parameters were related to the complex formation arising from NaOH-starch interactions. The rate constant K defined uniformly for an entire process increased with NaOH concentration and was power-law dependent. Furthermore, it was suggested that gelatinization evolved non-uniformly over time. A non-uniform analysis was then performed by disassembling the entire process into several elementary stages and revealed the evolutionary process for K.