Physical activity would bring in plenty of health benefits, especially recreational physical activity (RPA). Previous studies have suggested that built environment would affect older people’s recreational walking (RW) and RPA, but how the effects exist in a small-scale Chinese city remains unclear. Two hundred and fifty-two older participants were recruited in the city of Yiwu using cross-sectional survey of random samples in 2019. RW and RPA level of participants and perceived scores of built environments were collected using the International Physical Activity Questionnaire and Neighborhood Environment Walkability Scale, respectively. Linear regression analysis was conducted to investigate the association of built environment with older people’s RW and RPA. The results showed that two main factors affecting older people’s RW and RPA were residential density and aesthetics. Additionally, access to services was related to RW, and street connectivity was correlated with RPA. The associations of RW with built environment varied slightly with demographic variables included in the regression model. All the results suggested that lower residential density, better aesthetics environment, and higher street connectivity would motivate older people to engage more in RW and RPA. The better access to services encourages only RW, not RPA, in older people. These findings would be helpful for policy decision makers in the urban construction process in Yiwu. More studies are needed to enlarge the scientific evidence base about small-scale cities in China.

Badminton is very popular on college campuses. In badminton, the anterior cruciate ligament of the players has a higher risk of injury. There are many studies investigating the impact of fatigue on the injury of professional athletes, but few studies focused on college students. We hypothesized that the knee joint would experience greater ground reaction forces, valgus moments, and flexion moments of lunge contact in amateur after fatigue than those indicators before fatigue. Ten male badminton amateurs were enrolled in this study. They performed a lunge to hit the shuttlecock at the designated position and then quickly returned to the starting position before and after fatigue. Fatigue was induced by repeated isokinetic flexion/extension of the knee. Lower body kinematics and ground reaction force (GRF) were collected and further used to calculate the lower body joint moments from initial contact to maximum knee flexion. Compared to the pre-fatigue condition, the peak flexion moment (p = 0.012) and peak abduction moment of knee joint (p = 0.01), and maximum horizontal ground reaction force (p = 0.027) increased significantly at the initial contact (p = 0.01). After muscle fatigue, the knee buckling moment and valgus moment increased significantly at initial contact, and the horizontal backward maximum GRF also increased significantly. These changes might increase the injury risk of anterior cruciate ligament (ACL). The fatigue of the muscles around the knee joint did not change the maximum GRF in the vertical direction at the moment of contact. Combined with the results of our study, badminton coaches and teachers should increase the training of lower extremity muscle strength and endurance in our daily class and training, and also should pay special attention to the coordinated development of muscles.

Physical activity has been suggested to be beneficial in preventing disease and improving body function in older people. Older people’s leisure-time physical activity (LTPA) is affected by various factors, especially environmental factors. However, the differences in the association between older people’s LTPA and the built environment in different sex groups remain unclear. Perceived built environment scores and older people’s LTPA were collected for 240 older people in Jinhua using the Neighborhood Environment Walkability Scale and International Physical Activity Questionnaire, respectively. A linear regression method was used to analyze the associations between older people’s LTPA and the built environment in men, women, and all participants. The results showed that land use mix diversity was associated with LTPA in older people for both sexes. In men, LTPA was also associated with access to services. However, in women, LTPA was associated with residential density, street connectivity, and crime safety. The relationship varied when demographic variables were incorporated into the regression analysis. Those results indicated that a shorter perceived distance from home to destination would motivate older people to engage more in LTPA. Older people’s LTPA was affected by various built environment factors according to different sex groups. Women’s LTPA was generally more sensitive to the built environment. More studies are needed to confirm the association between LTPA in older people and the built environment in men and women in mid- or small-sized Chinese cities in the future.

Physical activity and health are of significant importance for the rapid aging population in China. Built environment has been suggested to be associated with elderly physical activity and health. However, the association differences between cities remain unclear. Perceived built environment scores and elderly leisure-time physical activity (LTPA) of 308 elderly in Hangzhou and 304 elderly in Wenzhou were collected using Neighborhood Environment Walkability Scale and International Physical Activity Questionnaire, respectively. A multivariate linear regression method and T-test were used to analyze of the associations between elderly LTPA and built environment and the differences between the two cities, respectively. The results showed that LTPA was positively associated with walking/cycling facilities and crime safety in both cities. LTPA was positively correlated with residential density, aesthetics, pedestrian/traffic safety in Wenzhou and negatively correlated with access to services in Hangzhou. The perceived scores of aesthetics (2.71 vs. 2.45) and pedestrian/traffic safety (2.11 vs. 1.71) in Hangzhou were significantly higher than those in Wenzhou. The results suggested that built environment elements like higher walking/cycling facilities and crime safety may motivate elderly engaging LTPA in both cities. However, LTPA was affected by different factors in these two cities. In the urban redevelopment, survey conducted in its own city would provide meaningful information and cannot be neglected.

Purpose: The purpose of this study was to examine biomechanical performance of the foot-up serve (FUS) in female tennis players at different skill levels.Methods: FUS analysis was completed in the biomechanical laboratory by 32 female college tennis players at three different levels. During FUS, 3D-biomechanical data from tennis players’ lower limbs were collected. One-way ANOVA was used to examine differences in kinematic and kinetic data between groupsResults: Range of motion (ROM) of bilateral lower-limb joints revealed significant differences in kinematics performance during both the preparation and landing cushion phases (p < 0.05). During preparation, Level 3 was significantly longer than Level 2 (P-a = 0.042, P-b = 0.001, and P-c = 0.006). During the flight phase, significant differences between levels 1 and 3 (P-a:0.002) and levels 1 and 2 (P-c:0.000) were discovered (P-a:0.002 and P-c:0.000). There were significant height differences between levels 1 and 2 as well as between levels 1 and 3. (P-a = 0.001, P-c = 0.000). During serve preparation (P-c = 0.001) and landing, GRF’s peak was significantly higher than level 3. (P-c:0.007). Significant differences were found between groups in the LLS preparation stage, with level 3 significantly higher than levels 1 and 2. (P-a = 0.000, P-b = 0.001, and P-c = 0.000); during landing, level 2 LLS was significantly higher than levels 1 and 3. (P-a = 0.000, P-b = 0.000, and P-c = 0.035).Conclusion: The range of motion of joints and the stiffness of the lower limbs have a significant impact on a tennis player’s FUS performance. A larger of joint mobility and lower-limb stiffness promote better performance during the FUS preparation stage.

The aim of this study was to examine the effect of built environment (BE) elements on older people’s (OP) leisure-time physical activity (LTPA) and leisure-time walking (LTW) level in the city of Ningbo. Older participants numbering 312 were randomly recruited using cross-sectional survey in 2019. International Physical Activity Questionnaire-short version (IPAQ-S) and Neighborhood Environment Walkability Scale—abbreviated (NEWS-A)—were used to gather LTPA data and the perceive scores of BE, respectively. Liner regression analysis was performed to investigate the association relationship between the perceived scores of BE and OP’s LTW and LTPA. The study’s results showed that, when not considering different sex groups, OP’s LTW was significantly related with the perceived scores of access to services (AE, p = 0.045), walking/cycling facilities (W/CF, p = 0.007), aesthetics, and land use mix diversity (LUMD, p = 0.04). OP’s LTPA was significantly related with AE (p = 0.04) and aesthetics (p < 0.001). The association relationships of BE with LTW and LTPA varied in different sex groups. Three elements (AE, W/CF, and LUMD) and one element (pedestrian/traffic safety and P/TS) of BE were found be related with older male and older female’s LTW, respectively. One element (aesthetics) and two elements (aesthetics, LUMD) of BE were found be related with older male and older female’s LTPA, respectively. The results indicated that the effects of BE on OP’s LTW and the effects of BE on OP’s LTPA were different. The effect also varied in different sex groups. More studies are needed to confirm the effect of BE on OP’s LTW and LTPA in different sex groups to globally enrich the scientific data base.