Hip-knee coupling in rugby place kicking at three different distances

The purpose of the study was to investigate hip-knee coupling in rugby place kickers, kicking at three different distances from the posts (40 m, 32 m, and 22 m). An optoelectronic motion capture system consisting of ten cameras was used for capturing total body kinematic data. Data collection took place outdoor, on a rugby field. During the forward swing a period of in-phase is reported as both the hip and the knee were flexing, creating a whip-like action. Even though absolute changes in joint angles of hip flexion and knee extension were seen, no changes were reported for the coordination patterns when kicking at different distances (22 m, 32 m, 40 m), indicating no change in movement strategy when kicking at different intensities

Positional in-match running demands of university rugby players in South Africa

CITATION: Donkin, C., et al. 2020. Positional in-match running demands of university rugby players in South Africa. Frontiers in Psychology, 11:1591, doi:10.3389/fpsyg.2020.01591.The original publication is available at https://www.frontiersin.orgPublication of this article was funded by the Stellenbosch University Open Access FundThe implementation of the Varsity Cup rugby competition among South African universities has sparked interest in university rugby cultures around the country. The Varsity Cup has established itself as one of the most important rugby competitions for full-time students. The development of specific conditioning programs for rugby players requires a thorough understanding of the game and the unique demands of playing positions. Therefore, the study aimed to investigate the in-match running demands of South African university rugby players by using GPS during match play for primary and secondary positional groups. Rugby players (n = 40) from two universities were assessed during match play (n = 17) over a competitive season by using GPS. Players were grouped into two primary positional groups, forwards (n = 22) and backs (n = 18), and five secondary positional groups, tight forwards (n = 14), loose forwards (n = 8), half backs (n = 5), inside backs (n = 6), and outside backs (n = 7). The GPS analysis provided the following match-play movements: total distance, high-speed meters, maximum velocity, match intensity, the number of accelerations and decelerations, and velocity zone. Halfbacks recorded the highest total distance (6620.9 ± 784.4 m; p = 0.02) and match intensity (77.7 ± 11.6 m/min; p = 0.01). Outside backs recorded the highest maximum velocity (8.385 ± 1.242 m/s; p = 0.00). Loose forwards registered the highest number of accelerations (385.5 ± 122.1) and decelerations (378.7 ± 108.1). Backs and their specific subgroups play at and within high velocity thresholds, significantly higher (p = 0.01) than that of the forwards. Forwards tend to be involved in a higher amount of accelerations and decelerations during match play, suggesting that forward play is at close quarters to the opposition. During university rugby matches, the backs covered greater distances and speeds than the forwards, whereas the forwards achieved more accelerations and decelerations than backs. Results from the study can assist Varsity Cup strength and conditioning coaches to prepare players for the position-specific demands of the competition.https://www.frontiersin.org/articles/10.3389/fpsyg.2020.01591/fullPublisher's versio

Country profile: sport in South Africa

status: publishe

Relationship between functional movement screening and performance tests in elite university female netball players

The use of Functional Movement Screening (FMSTM) for elite university female netball players was investigated by evaluating the relationship between FMSTM total score and various performance tests. Out of 20 netball players, 19 completed the FMSTM screen consisting of deep overhead squat, hurdle step, in-line lunge, active straight leg raise, shoulder stability, trunk stability and rotary stability; and the performance tests consisting of maximum vertical and lateral jumps, 5m- and 10m-sprints, 5-0-5 agility tests and repeated sprints. Spearmanꞌs correlations (p≤0.05) examined the relationships between the FMSTM and performance tests. Players with higher FMSTM total scores were faster on the 5-0-5 agility test (r=-0.52, p=0.02) and covered more distance in the repeated sprints test (r=0.51, p=0.03). Agility 5-0-5 test was also significantly associated with repeated sprints (r=-0.87, p=0.02), while no significant relationships were found with 5m- or 10m-sprints. Due to specific demands of netball, female players develop physical performance characteristics that do not depict strong association with the FMSTM assessment. Coaches and trainers should use both tools for comprehensive performance evaluation of their players.Keywords: Functional movement screening; Netball; Agility; Spee

Sleep-Related Issues for Recovery and Performance in Athletes

The body of research that reports the relevance of sleep in high-performance sports is growing steadily. While the identification of sleep cycles and diagnosis of sleep disorders are limited to lab-based assessment via polysomnography, the development of activity-based devices estimating sleep patterns provides greater insight into the sleep behavior of athletes in ecological settings. Generally, small sleep quantity and/or poor quality appears to exist in many athletic populations, although this may be related to training and competition context. Typical sleep-affecting factors are the scheduling of training sessions and competitions, as well as impaired sleep onset as a result of increased arousal prior to competition or due to the use of electronic devices before bedtime. Further challenges are travel demands, which may be accompanied by jet-lag symptoms and disruption of sleep habits. Promotion of sleep may be approached via behavioral strategies such as sleep hygiene, extending nighttime sleep, or daytime napping. Pharmacological interventions should be limited to clinically induced treatments, as evidence among healthy and athletic populations is lacking. To optimize and manage sleep in athletes, it is recommended to implement routine sleep monitoring on an individual basis

Growing-up (habitually) barefoot influences the development of foot and arch morphology in children and adolescents

CITATION: Hollander, K., et al. 2017. Growing-up (habitually) barefoot influences the development of foot and arch morphology in children and adolescents. Scientific Reports, 7:8079, doi:10.1038/s41598-017-07868-4.The original publication is available at https://www.nature.comThe development of the human foot is crucial for motor learning in children and adolescents as it ensures the basic requirements for bipedal locomotion and stable standing. Although there is an ongoing debate of the advantages and disadvantages of early and permanent footwear use, the influence of regular barefootness on foot characteristics in different stages of child development has not been extensively evaluated. A multicenter epidemiological study was conducted to compare the foot morphology between habitually barefoot children and adolescents (N = 810) to age-, sex- and ethnicity-matched counterparts that are used to wearing shoes. While controlling for confounders, we found that habitual footwear use has significant effects on foot-related outcomes in all age groups, such as a reduction in foot arch and hallux angles. The results indicate an impact of habitual footwear use on the development of the feet of children and adolescents. Therefore, growing up barefoot or shod may play an important role for childhood foot development, implying long-term consequences for motor learning and health later in life.https://www.nature.com/articles/s41598-017-07868-4Publisher's versio

Motor Skills of Children and Adolescents Are Influenced by Growing up Barefoot or Shod

Background: The objective of this study was to evaluate the association between growing up barefoot or shod and the development of motor performance during childhood and adolescence.Methods: Habitual barefoot and shod children and adolescents between 6 and 18 years were recruited in South Africa and Germany. Participants completed balance, standing long jump and 20 m sprint tests in barefoot and shod conditions. Outcomes were analyzed in separate mixed-effects linear regressions for three age groups according to stages of development (6–10, 11–14, and 15–18 years). All models were adjusted for confounders: sex, ethnicity, BMI, PAQ score and order of tests (barefoot vs. shod).Results: Three hundred and eight-five habitually barefoot and 425 habitually shod children participated. Significant age by footwear effects were found for the jump (p = 0.032) and sprint test (p = 0.041). Habitually barefoot children aged 6–10 years scored higher in the balance test (p = 0.015) and standing long jump (p = 0.005) whereas habitually shod children sprinted faster (p < 0.001). Faster sprint times were found for habitually shod participants between 11 and 14 years (p < 0.001). Habitually barefoot adolescents between 15 and 18 years of age showed a greater long jump distance (p < 0.001) but slower sprint times (p = 0.014) than shod adolescents.Conclusions: The results emphasize the importance of footwear habits for the development of motor skills during childhood and adolescence. Regular physical activities without footwear may be beneficial for the development of jumping and balance skills, especially in the age of 6 to 10 years

Foot strike patterns differ between children and adolescents growing up barefoot vs. shod

CITATION: Hollander, K., et al. 2017. Foot strike patterns differ between children and adolescents growing up barefoot vs. shod. International Journal of Sports Medicine, 39(02):97-103, doi:10.1055/s-0043-120344.The original publication is available at https://www.thieme-connect.deEffects of early and permanent footwear use are not well understood. The aim of this study was to investigate the effects of habituation to footwear on foot strike patterns of children and adolescents. Healthy habitually barefoot and shod participants (aged 6–18 years) from South Africa (n=288) and Germany (n=390) performed multiple 20-m jogging and running trials with and without shoes. Each foot strike was captured using a high-speed camera to determine a rearfoot or non-rearfoot strike. The probability of a rearfoot strike in both cohorts and each age was analyzed by using a mixed-effects logistic regression adjusted for possible confounders. Habitually barefoot children showed a higher probability of using rearfoot strikes than habitually shod children (p<0.001). The probability was age-dependent and decreased in habitually barefoot children with age (ORbarefoot-jogging=0.82, 95% CI, 0.71 to 0.96, p=0.014; ORbarefoot-running=0.58, 95% CI, 0.50 to 0.67, p<0.001 and ORshod-running=0.68, 95% CI, 0.59 to 0.79, p<0.001). In habitually shod children, the probability increased significantly for shod jogging (OR=1.19, 95% CI, 1.05 to 1.35, p=0.006). To conclude, foot strike patterns of children are influenced by habituation to footwear. Younger habitually barefoot children show higher rates of rearfoot strikes for shod and barefoot running, and it converges in later adolescence.https://www.thieme-connect.de/DOI/DOI?10.1055/s-0043-120344Publisher's versio

Image_1_Motor Skills of Children and Adolescents Are Influenced by Growing up Barefoot or Shod.pdf

<p>Background: The objective of this study was to evaluate the association between growing up barefoot or shod and the development of motor performance during childhood and adolescence.</p><p>Methods: Habitual barefoot and shod children and adolescents between 6 and 18 years were recruited in South Africa and Germany. Participants completed balance, standing long jump and 20 m sprint tests in barefoot and shod conditions. Outcomes were analyzed in separate mixed-effects linear regressions for three age groups according to stages of development (6–10, 11–14, and 15–18 years). All models were adjusted for confounders: sex, ethnicity, BMI, PAQ score and order of tests (barefoot vs. shod).</p><p>Results: Three hundred and eight-five habitually barefoot and 425 habitually shod children participated. Significant age by footwear effects were found for the jump (p = 0.032) and sprint test (p = 0.041). Habitually barefoot children aged 6–10 years scored higher in the balance test (p = 0.015) and standing long jump (p = 0.005) whereas habitually shod children sprinted faster (p < 0.001). Faster sprint times were found for habitually shod participants between 11 and 14 years (p < 0.001). Habitually barefoot adolescents between 15 and 18 years of age showed a greater long jump distance (p < 0.001) but slower sprint times (p = 0.014) than shod adolescents.</p><p>Conclusions: The results emphasize the importance of footwear habits for the development of motor skills during childhood and adolescence. Regular physical activities without footwear may be beneficial for the development of jumping and balance skills, especially in the age of 6 to 10 years.</p