Reference Values of Spatial and Temporal Gait Parameters in a Contemporary Sample of Spanish Preschool Children: A Cross-Sectional Study.

The aim of this study was to analyze the influence of age and sex on kinematic gait parameters in preschool children, and derive reference values for this population. A total of 383 preschool children (age 3-5 years; 207 girls, 176 boys) participated in this study. We used the OptoGait system to assess the kinematics of gait at a comfortable and self-determined speed. No significant differences between the sexes were found for the main gait parameters. Among the participants, there was a significant increase in double support, reductions in absolute cadence and the coefficient of variation (CV) of cadence, an increase in absolute step length (SL), and an increase in the walk ratio (WR) from 3 to 5 years of age. However, the normalized SL and normalized WR displayed a significant reduction in both sexes. Partial correlation indicated a significant association of age with SL and normalized SL, and WR. Additionally, WR showed a significant correlation with the CV of cadence. To summarize, no relevant differences in gait performance were found according to sex; however, age was found to influence gait maturation. The normative values established for Spanish preschool children can be used to monitor healthy gait development.

Cardiac Evaluation of Exercise Testing in a Contemporary Population of Preschool Children: A New Approach Providing Reference Values.

The objective of this study was to evaluate cardiac autonomic function at rest, during maximal exercise, and in post-exercise recovery, to determine sex-specific and age-specific differences in resting heart rate (RHR), linear and spectral parameters of Heart Rate Variability (HRV), HRpeak, and heart rate recovery (HRR) after one and five minutes, in preschool children. This study involved a cohort of 167 healthy children (79 girls) aged 3 to 6 years that were selected from several schools in southern Spain. A 10 × 20 m test was conducted, and the cardiovascular response was recorded. No significant differences were found in all variables between the sexes. However, a significant reduction in RHR and an increase in HRR were found from age 4 to age 6. HRV parameters at rest were higher in older children. No associations between 10 × 20 m performance, weight status, and cardiac parameters were found. Simple linear regression analysis revealed that heart rate reserve (HRr), HRR5min, RMSSD, and HF were the variables that showed association with all HR parameters. There was also a significant correlation between HRr and HRR5min. In conclusion, cardiovascular autonomic function during rest, exercise, and recovery in Spanish preschool children was not influenced by sex, although older children showed greater cardiovascular modulation. Cardiorespiratory fitness status was not associated with HR response.

Effects of a 10-week running-retraining programme on the foot strike pattern of adolescents: A longitudinal intervention study.

BACKGROUND: The purpose of this study was to analyse the effects of ten weeks of different running-retraining programmes on rearfoot strike (RFS) prevalence in adolescents. RESEARCH QUESTION: it is possible to change foot strike pattern in adolescents? METHODS: A total of 180 children (45.3% girls), aged 13-16 years, participated in this intervention study. The children were randomly assigned to one of three experimental groups (EGs) that each carried out a different retraining programme, based on running technique (n = 39), a 15% increased step frequency (SF) (n = 37) and barefoot training (n = 30), performed for three days each week. A control group (CG) (n = 43) did not perform any retraining. A 2D video-based analysis (240 Hz) was used to determine the RFS. RESULTS: At baseline, no significant differences in RFS prevalence were found between the EGs and the CG in either the left (χ2 = 2.048; p = 0.559) or the right foot (χ2 = 0.898; p = 0.825). In the post-test, no significant differences were found for the left foot (χ2 = 7.102; p = 0.069), but there were significant differences for the right foot (χ2 = 9.239; p = 0.025) were observed. In the re-test, no significant differences were found for either the left foot (χ2 = 2.665; p = 0.273) or the right foot (χ2 = 2.182; p = 0.325). In addition, no group displayed significant changes in RFS prevalence from the pre-test to the re-test. There was a trend towards a reduction in the RFS prevalence in both the increased SF group and the barefoot group. MEANING: The main finding of this study was that certain running-retraining programmes performed three times per week for ten weeks are not enough to modify the adolescent foot strike pattern (FSP).

Analysis of foot strike pattern, rearfoot dynamic and foot rotation over childhood. A cross-sectional study.

The purpose of this study was to determine the foot strike patterns (FSP), rearfoot position at initial contact (RPic, i.e., No INV/EVE) and foot rotation in children in relation to age. A total of 932 children aged 3 to 16 years participated in this study. A sagittal and frontal-plane video was recorded using a high-speed camcorder to analyse these variables. There is a significant increase (p < 0.001) of rearfoot strike patterns (RFS) prevalence in relation to age; e.g. preschool children (3-6 years old) displayed an RFS prevalence 46.65% and the adolescent population(15-16 years old) an RFS prevalence 92.20%. The total RFS prevalence in all samples was 69.25%. There was a significant reduction (p < 0.001) of prevalence of RPic in relation to age groups; preschool children displayed a prevalence of RPic 60.37% and the adolescent population 10%. There was a significant reduction (p < 0.001) of prevalence of no foot rotation in relation to age groups; preschool children displayed a prevalence of no foot rotation 48.95% and the adolescent population 13.55%. In conclusion, FSP in children are influenced by age. It is noteworthy that the RFS prevalence of children is lower in comparison to the adult population.