Regular physical activity is an important component of physical health of children and has been associated with increasing skeletal muscle mass and muscle strength. Children with low levels of ...physical activity may experience health problems, such as loss of muscle mass, later in life. Thus, it may be valuable to identify declining physical function in children who do not perform the recommended amount of physical activity. Therefore, we aimed to evaluate the relationship between the amount of physical activity performed for greater than or equal to60 min per day for greater than or equal to5 days per week and the skeletal muscle mass index and physical function in young children. In total, 340 typically developing children aged 6-12 years (175 girls; average age, 9.5±1.9 years) were included in this cross-sectional study. We evaluated the proportion of children performing the recommended minimum of 60 min of daily moderate-to-vigorous physical activity at least 5 days per week. The skeletal muscle mass and Gait Deviation Index scores, gait speed, grip strength, Five Times Sit-to-Stand test results, Timed Up-and-Go test results, one-leg standing time, and gait efficiency were evaluated. Multiple logistic regression analyses were performed to assess the association of moderate-to-vigorous physical activity with the skeletal muscle mass index, percent body fat, and physical function, after controlling for confounding factors (age and sex). A logistic regression analysis revealed that the skeletal muscle mass index was independently associated with moderate-to-vigorous physical activity (odds ratio, 2.34; 95% confidence interval, 1.17-4.71; P = 0.017). Performance of moderate-to-vigorous physical activity for greater than or equal to5 days per week for greater than or equal to60 min per day was associated with the skeletal muscle mass index score of Japanese children. Our findings highlighted the importance of performing moderate-to-vigorous physical activity for the development of skeletal muscle mass in children.
We aimed to develop gait standards for gait parameters in school-aged Japanese children and assess age-related differences in gait patterns and parameters. Children aged 6-12 years (n = 424) were ...recruited from two elementary schools. An instrumented three-dimensional gait analysis system was used to record each child's gait kinematics, kinetics, and spatiotemporal parameters. Participants were subdivided into three age groups (Group A, 6-8 years; Group B, 9-10 years; and Group C, 11-12 years). LMS Chartmaker, version 2.54, was used to create a developmental chart for the gait pattern. The non-normalized step and stride lengths were significantly longer, and the cadence was lower in older children; however, the opposite outcome occurred when analyzing normalized data. Ankle moment differed significantly by age, and the maximum ankle moment was higher in older children than that in younger children. Furthermore, the hip and knee flexion angles during gait and the normalized spatiotemporal parameters of Japanese children aged 6-12 years differed by age and from those of children from other countries. The centile chart of the gait pattern is a useful tool for clinicians to assess developmental changes in the gait pattern and detect gait abnormalities in children.
In April 2020, the Japanese government declared a state of emergency due to the novel coronavirus disease (COVID-19). Schools were closed and a stay-at-home order was issued in April and May 2020. ...This before-and-after study aimed to measure the effects of these COVID-19-related restrictions on physical function among Japanese children. The study included children aged 6–7 years, enrolled before and after the emergency declaration. Their body fat percentage, single-leg standing time, Gait Deviation Index score, and history of falls were compared. There were 56 and 54 children in the before and after groups, respectively. Children in the after group had a higher body fat percentage (p = 0.037), shorter single-leg standing time (p = 0.003), and a larger number of falls per month (p < 0.001) than those in the before group. In the logistic regression analysis, children in the after group had a significantly shorter single-leg standing time (odds ratio (OR): 0.985, 95% confidence interval (CI): 0.972−0.997, p = 0.013), a greater number of falls per month (OR: 1.899, 95% CI: 1.123−3.210, p = 0.017), and a higher body fat percentage (OR: 1.111, 95% CI: 1.016−1.215, p = 0.020) than those in the before group. The COVID-19 emergency restrictions had a negative effect on children’s physical function, especially on balance.
Low-back pain is common among school-aged children. Decreased trunk flexibility in childhood influences low-back pain in adulthood. Previous studies examining the association between low-back pain ...and trunk flexibility in children are insufficient. Examining this association among elementary school children may help to better understand trunk flexibility in children with low-back pain and to modify the management of inflexibility. Therefore, this study aimed to identify the prevalence of low-back pain and its relationship with physical function among elementary school students. School-aged children aged 6-12 years were recruited in Japan between May 2018 and March 2023. Fingertip-to-floor distance, back muscle strength, pelvic tilt angle during gait, and the visual analog scale for low-back pain were measured. In addition, factors independently related to low-back pain were determined through logistic regression analysis. Low-back pain was reported in 9.6% of the 394 participants (boys, 191; girls, 203). All children with low-back pain presented with back pain when they moved; however, the pain was non-specific. Logistic regression analysis showed that the fingertip-to-floor distance was an independent risk factor for low-back pain (odds ratio, 0.921; p = 0.007). The odds ratios calculated in the logistic regression analysis confirmed that low-back pain frequency increased as the fingertip-to-floor distance decreased. The risk of low-back pain was associated with inflexibility, regardless of sex and muscle strength. These findings suggest that children with low-back pain must increase their trunk and lower extremity flexibility.
Williams syndrome (WS) is a genetically based neurodevelopmental disorder characterized by intellectual disability and impaired visuospatial recognition. The aim of this study was to analyze the gait ...characteristics of WS children with impaired visuospatial recognition using a three-dimensional gait analysis (3DGA) to clarify the gait adaptation needed to compensate for it. 3DGA was performed in 8 WS children with impaired visuospatial recognition (mean age, 11.8 years) and 9 age-, sex-, height-, and weight-matched controls. Clinical data, fundamental motor tests, and gait variables while walking on a flat surface and walking up a mat were compared between the two groups, and the correlations between variables were analyzed in the WS children. WS children showed impairment of balance function without muscle weakness. In walking on a flat surface, the WS group showed reduced walking speed, short step length, increased variability of step length, increased knee flexion throughout the stance phase, increased horizontal pelvic range of motion (ROM), and a low Gait Deviation Index and a high Gait Profile Score, which are indices of gait quality. In walking up a mat, the WS group showed further reduced walking speed and decreased sagittal hip flexion and ankle dorsiflexion ROM in the swing phase. Impaired balance function was significantly correlated with increased variability of step length and decreased sagittal ankle dorsiflexion ROM in the swing phase. The detailed gait pattern of WS children with impaired visuospatial recognition was presented. These findings show that impaired visuospatial recognition and balance function contribute to gait adaptation.
Objective
To compare walking efficiency, and associated physical function, between children, with and without developmental coordination disorder trait.
Design
Cross-sectional study.
Setting
The ...study was conducted in a Medical and Rehabilitation Center for Developmental Disabilities in Okazaki, Japan.
Subjects
The study included 286 children, 6–12 years of age, with and without developmental coordination disorder trait. Developmental coordination disorder trait was defined by a score below the −1 standard deviation on the Japanese version of the Developmental Coordination Disorder Questionnaire. Based on this criterion, 45 children (28 boys) were classified into the developmental coordination disorder trait group and the other 241 (115 boys) in the control group.
Measures
The following physical function outcomes were measured: single leg stance test; step length variability; and walking efficiency, measured using the 2-min walk test. Logistic regression analysis was used to determine the association between developmental coordination disorder trait and lower walking efficiency and physical function.
Results
Compared to the control group, the developmental coordination disorder group showed lower walking efficiency (P = 0.026), higher step length variability (P = 0.047), and shorter single leg stance test (P = 0.001). Developmental coordination disorder was independently associated with walking efficiency (odds ratio, 1.03; 95% confidence interval CI, 1.001–1.061; P = 0.041) and single leg stance test (odds ratio, 0.99; 95% CI, 0.978–0.996; P = 0.006), but not to step length variability, age, and sex.
Conclusions
Lower walking efficiency increases energy expenditure in children with developmental coordination disorder trait. Interventions to improve walking efficiency could improve the physical function and participation of these children.
Children born late preterm (LP) have an increased risk of poor developmental motor outcomes.
This study aimed to assess physical functions and gait performance in school-aged children born LP.
...Cross-sectional study.
Physical functions and gait performance were evaluated in 277 children aged 6–10 years born LP (n = 22) and full-term (FT) (n = 255).
Physical function tests consisted of five times sit-to-stand test (FTSST), one-leg standing time, and grip strength. FTSST was used to assess the functional muscle strength of the lower limbs and dynamic balance function. Gait performance tests included gait quality, spatiotemporal gait parameters, and gait variability. Clinical data, physical functions, and gait performance were compared between two groups. Furthermore, logistic regression analysis was performed to assess the association between all variables and LP birth.
In physical function tests, children born LP showed poorer FTSST than those born FT (p = 0.039). No significant difference in gait performance tests were identified between the two groups. Logistic regression analysis of FTSST for LP (adjusted for age at assessment) revealed that FTSST was significantly associated with LP birth (p = 0.004, odds ratio = 1.579, 95% confidence interval = 1.160–2.149).
We demonstrated the physical functions and gait performance in school-aged children born LP. Our findings indicate that it is important to focus on the decreased functional muscle strength of the lower limbs and reduced dynamic balance function related to LP birth to improve functional mobility in children born LP.
•Children born late preterm (LP) showed poorer five times sit-to-stand test (FTSST).•No significant difference in gait performance was observed between LP and full-term.•Logistic regression analysis revealed the association between FTSST and LP birth.•FTSST is a useful measure for functional mobility in school-aged children born LP.
One major impact of the COVID-19 pandemic on children's lifestyles is the lack of exercise owing to activity restrictions. However, information regarding the way in which physical functions among ...children decline under these circumstances remains scarce. In this study, we compared the physical functions and life habits among children before and during the COVID-19 pandemic in Japan. The participants involved 40 children aged between 9-15 years (23 girls and 17 boys) who were examined medically both before and during the pandemic. The compared variables included muscle strength, static and dynamic balance functions, gait speed, body fat percentage, screen and sleep times, quality of life, and physical activity time. During the pandemic, compared to before the pandemic, children had lower levels of dynamic balance functions (
= 0.039), increased body fat percentages (
< 0.0001), longer screen time per day (
= 0.002), and shorter sleep time per day (
< 0.0001). Between the two periods, there were no significant differences in muscle strength, static balance functions, gait speed, quality of life, and physical activity time. The activity restrictions imposed as a result of the COVID-19 pandemic negatively affect dynamic balance functions, body-fat levels, and life habits among children.
Exercise improves physical health and positively impacts physical functions in children. Additionally, the habitual exercise established during childhood often continues into adulthood. Therefore, ...childhood is an important period for establishing healthy habits. Investigating the relationship between the presence or absence of daily exercise and physical functions may provide important information to confirm poor physical function in children with poor exercise habits. Therefore, this study examined the relationship between exercise habits as defined by the Japanese Ministry of Health, Labor, and Welfare and physical function in children aged 9-12 years. Approximately 239 children were included in this study. Participants answered a questionnaire about their exercise habits. We evaluated the skeletal muscle mass index, grip strength, standing broad jump, one-leg standing time, and gait deviation index. Logistic regression analyses were performed to assess exercise habit association with skeletal muscle mass index, physical function, and gait deviation index after adjusting for sex. Of the 239 children, 75.5% (n = 178) had exercise habits. A significant association was noted between exercise habits and skeletal muscle mass index and standing broad jump (skeletal muscle mass index: OR, 1.84; 95% CI, 1.01-3.36 and p<0.05; standing long jump: OR, 1.02; 95% CI, 1.00-1.04 and p<0.05). In conclusion, exercise regardless of exercise level for at least 30 min per day, 2 days per week, for at least 1 year is important for skeletal muscle mass and instantaneous lower limb muscular strength development in school-aged children.
The response of muscle oxygen saturation, which is an index for the energy metabolism of muscles during walking in children, and its relationship to the physiological cost index, which indicates ...walking efficiency, are unknown. This study aimed to evaluate muscle oxygen saturation in lower extremity muscles during walking in children, its changes with age, and the relationship between the physiological cost index. The oxygen saturation was measured by the amount of change during a two-minute walk, and the physiological cost index was calculated from the change in heart rate before and after exercise and walking speed. Results were compared for each muscle, and the correlation between the two was examined. Changes in muscle oxygen saturation were greater in the lower leg muscles, significantly greater in the tibialis anterior at six to seven years, and in the gastrocnemius medial head at eight to ten years. The physiological cost index was significantly correlated with changes in muscle oxygen saturation in the tibialis anterior (r = 0.44, p < 0.001). The lower leg muscles were metabolically active in children’s gait, and their response varied with age. Moreover, the muscle oxygenation dynamics of the tibialis anterior may influence walking efficiency.