Objective: To explore the impact of situational sport games on gross movement and social development among children aged 4-5 years, and to provide references for promoting the healthy development of preschool children. Methods: Seventy one children aged 4-5 were randomly selected from one public kindergarten in Beijing during Apr. to Jul. of 2019 and were randomly divided into experimental group ( n =36, 8 week situational sports game intervention) and control group ( n =35, regular learning and playing). The Test of Gross Motor Development (TGMD-3) and social development scale for children aged 3-9 were used to assess gross movement and social development, respectively, which were then compared and analyzed. Results: Before intervention, the total score of gross motor development[intervention group (42.63±7.62), control group (43.00±9.16)] and social development[intervention group (211.88±6.68), control group (212.71±9.80)] showed no significant differences between the two groups( t =-0.18，-0.37， P >0.05). After intervention, increases in gross motor development[intervention group (67.80±9.80), control group (45.68±9.47)] and social development level[intervention group (228.30±6.37), control group (214.71±8.65)] were observed in both groups( t =25.82，3.22；15.90，2.13， P <0.05), with gross movement and social development scores higher in intervention group than that of the control group( t =9.66，7.54， P <0.05). Conclusion 8 week situational sports games can promote gross movement and social development of 4-5 year old children. It is suggested that interventions to promote early childhood development should be aware of multiple dimensions of development.

Objective The single leg support tree pose and Yan balace of yoga was selected to compare the biomechanical characteristics of lower limb joint angles, joint force and muscle strength for professional and non-professional yoga practitioners, so as to provide theoretical basis for scientific fitness of yoga beginners and exercise prescription determined by rehabilitation physicians. Methods BTS infrared motion capture system was used to collect kinematic data, Kistler forceplate was used to collect dynamic data, AnyBody 7.0 simulation software was used to calculate the joint force and muscle strength, and Biodex balance system was used to evaluate the stability of single support. Results In both tree pose and Yan balance, the muscle strength of lower limbs in professional group was greater than that in non-professional group. Support leg of tree pose: the muscle strength of the tibialis anterior, gluteus medius posterior, iliac medialis and sartorius in professional group was greater than that in non-professional group (P<0.05). Balance leg of tree pose: the muscle strength of the biceps femoris breve, sartorius, piriformis, gemellus inferior, iliac lateralis, iliac medialis, gluteus maximus inferior, obturator internus in professional group was greater than that in non-professional group (P<0.05). Support leg of Yan balance: the muscle strength of tibialis anterior, extensor digitorum longus, extensor hallucis longus, obturator internus, gluteus maximus superior in the professional group was greater than the non-professional group (P<0.05). Balance leg of Yan balance: The muscle strength of extensor hallucis longus in professional group was greater than that in non-professional group (P<0.05). The scores of front-rear, overall of PS-BI, overall, front-rear, left-right of athlete single leg (ASL) in professional group were significantly lower than those in non-professional group (P<0.05). Conclusions The joint angle will affect the degree of muscle exercise in lower limbs. During yoga practice, attention should be paid to the standard of postures and the exercise of corresponding muscles. In tree pose, the muscle strength of both legs in non-professional group was significantly different from that in professional group, and the difference in Yan balance was more obvious on the supporting leg. Yoga practice can improve the stability of single leg support in multiple directions.

ObjectiveTo investigate the influence of interference tasks and age on gait characteristics and task costs of children aged three to eight years. MethodsFrom April to August, 2021, 200 children from a kindergarten and primary school in Cangzhou, Hebei were enrolled to collect gait spatiotemporal parameters and kinematics data with infrared motion capture system; ground reaction force was collected with the Kistler force platform and simulated with Anybody 7.0, as walking naturally (standard gait), answering question (cognitive gait) and crossing obstacle (obstacle-crossing gait). ResultsA total of 182 children finished the test. The main effect of task was significant on spatiotemporal parameters (F > 5.167, P < 0.01), as well as age (F > 2.321, P < 0.05), except on stride width and speed; while the interaction effect of task and age was significant on double stance phase, single stance phase and step length (F > 3.040, P < 0.01). The main effect of task was significant on kinematics data (F > 83.019, P < 0.001), as well as age (F > 2.359, P < 0.05), except on range of motion of knee and maximum angular velocity of ankle; while the interaction effect of task and age was significant (F > 2.066, P < 0.05), except on range of motion of hip. The main effect of task and age was significant on kinetic parameters (F > 4.032, P < 0.05); while the interaction effect of task and age was significant (F > 2.189, P < 0.05), except on the strength of medial soleus, lateral gastrocnemius, medial gastrocnemius and tibialis anterior. The coefficient of variation was the most for cognitive gait, and then for the obstacle-crossing gait and standard gait. The main effect of task and age was significant on the cost of task for stride length and speed (F > 3.368, P < 0.01), while the interaction effect was not significant. ConclusionGait of early childhood is influenced by interference tasks and age. Under interference tasks, gait cycle increases, while single stance phase, stride length, frequency and speed decrease; and task costs increase, and overall gait stability decrease. Cognitive tasks impact on gait greater than obstacle crossing, which may be due to the higher costs of tasks. In terms of age, gait exhibits a non-linear age trend.