Kicking Performance in Young U9 to U20 Soccer Players: Assessment of Velocity and Accuracy Simultaneously

Purpose: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. Method: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (V_ball), foot velocity (V_foot), V_ball/V_foot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. Results: Ball velocity increased by 103% (p < .001, η² = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η² = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot–ball impact (V_ball/V_foot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η² = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13–U15). Last stride length was correlated, low to moderately high, with V_ball in all age groups (r = .36–.79). Conclusions: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players.     

Prevalence of urinary incontinence in high-impact sports athletes and their association with knowledge,attitude and practice about this dysfunction

Objective: To evaluate the prevalence of urinary incontinence (UI) in female athletes practising high-impact sports and its association with knowledge, attitude and practice (KAP).

Design: Observational study.

Methods: A semi-structured evaluation form, KAP survey and the International Consultation on Incontinence Questionnaire – Short Form were used. Univariate and multivariate analyses were performed to verify the association of UI with KAP, sociodemographic, gynaecological and sports-related variables, with significant variables remaining in the model (p?Results: The prevalence of UI in 118 athletes was 82 (70%), of which 19 (23%) had pure stress UI, 19 (23%) had pure urgency UI and 44 (54%) had mixed UI; with 50 (61%) athletes losing urine during training and 37 (45%) during competitions. Regarding the KAP survey, 37 athletes (31%) demonstrated adequate knowledge, 63 (53%) adequate attitude and zero adequate practice. In the multivariate analysis, a sports practice time of over 8 years and dyspareunia presented significant values, with odds ratios (OR) of 2.66 and 2.99, respectively. Knowledge was significantly associated with UI (OR 0.43). UI had a slight impact on QOL.

Conclusions: There is a high prevalence of UI yet low levels of adequate knowledge and practice regarding the occurrence of UI in sports, with sports practice time over 8 years and dyspareunia factors predisposing female athletes to UI by 2.7 and 3 times, respectively. Athletes with adequate knowledge were 57% less likely to develop UI.     

Teacher and school determinants of perceived classroom discipline: a multilevel analysis of TALIS 2013

Learning Environments Research - Classroom discipline is a significant concern in most educational systems and a critical element of an effective learning environment. In this article, we present a...