Ranel Venter

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

The 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.

Recovery and Performance in Sport : Consensus Statement

The relationship between recovery and fatigue and its impact on performance has attracted the interest of sport science for many years. An adequate balance between stress (training and competition load, other life demands) and recovery is essential for athletes to achieve continuous high-level performance. Research has focused on the examination of physiological and psychological recovery strategies to compensate external and internal training and competition loads. A systematic monitoring of recovery and the subsequent implementation of recovery routines aims at maximizing performance and preventing negative developments such as underrecovery, nonfunctional overreaching, the overtraining syndrome, injuries, or illnesses. Due to the inter- and intraindividual variability of responses to training, competition, and recovery strategies, a diverse set of expertise is required to address the multifaceted phenomena of recovery, performance, and their interactions to transfer knowledge from sport science to sport practice. For this purpose, a symposium on Recovery and Performance was organized at the Technical University Munich Science and Study Center Raitenhaslach (Germany) in September 2016. Various international experts from many disciplines and research areas gathered to discuss and share their knowledge of recovery for performance enhancement in a variety of settings. The results of this meeting are outlined in this consensus statement that provides central definitions, theoretical frameworks, and practical implications as a synopsis of the current knowledge of recovery and performance. While our understanding of the complex relationship between recovery and performance has significantly increased through research, some important issues for future investigations are also elaborated.

The effect of the law changes on time variables of the South African Currie Cup Tournament during 2007 and 2013

In rugby union, several law changes were introduced between 2007 and 2013, yet the impact of these changes have not been evaluated. The aim of this study was to determine the impact of the law changes on the time intervals and contact profile of the South African Currie Cup Tournament during the 2007 and 2013 seasons. The frequencies of 15 performance indicators were used for the aim of this study. The time interval profiles revealed that the total match time and total stoppage time increased significantly (p < 0.01), while the total ball in play time decreased significantly (p < 0.01). The individual phase activity also indicated a significant decrease p < 0.01). The contact profile revealed that the total tackle time increased significantly (p < 0.01), while the total ruck/maul-, scrum-and line-out-times decreased significantly (p < 0.01). The study revealed that the profile of the South African game has become more continuous, with total time spent at rucks/mauls and between subsequent rucks decreasing. The findings of this study can assist coaches and trainers with information to re-create match situations during training in order to improve performance during match play.

Foot Strike Patterns Differ Between Children and Adolescents Growing up Barefoot vs. Shod

Effects 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 (OR barefoot-jogging =0.82, 95% CI, 0.71 to 0.96, p=0.014; OR barefoot-running =0.58, 95% CI, 0.50 to 0.67, p<0.001 and OR shod-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.

Changes on the match profile of the South African Currie Cup tournament during 2007 and 2013

In rugby union, several law changes were implemented between 2007 and 2013, yet the impact of these law changes on the profile of the game has not been assessed to date. The aim of this study was to determine the effect of the law changes on the scoring, time interval, general skills and contact profiles of the South African Currie Cup during the 2007 (n = 37) and 2013 (n = 33) seasons. A total of 70 matches were analysed using video analysis software. The frequencies of 37 performance indicators were used to address the aim of the study. The scoring profile revealed that fewer tries were scored (p = 0.07), while the number of penalty goals increased significantly (p < 0.01). The time interval profile showed that stoppages decreased significantly (p < 0.01). The skills profile revealed a significant increase in the number of passes (p < 0.01) and a decrease in the number of handling errors, offloads and kicks (p < 0.01). The contact profile revealed a significant increase in the number of rucks/mauls and tackles completed (p < 0.01) and a decrease in scrums and line-outs (p < 0.01). The study revealed that the South African game have move to a game that is more physical and continuous.

Backward compared to forward over ground gait retraining have additional benefits for gait in individuals with mild to moderate Parkinson’s disease: A randomized controlled trial

Over ground gait retraining in the reverse direction has shown to be beneficial for neurological rehabilitation, but has not yet been investigated in Parkinsons disease (PD). Backwards walking (BW) might be a useful training alternative to improve PD gait and possibly reduce fall risk during complex multi-directional daily activities. The primary aim was to compare the effect of an eight-week forward (FWG) and backwards (BWG) gait retraining program on gait parameters in PD individuals. Twenty-nine participants (aged 71.0±8.8years; UPDRS-III 38.1±12.3; H&Y 2.7±0.5) were randomly assigned to either the control (FWG; n=14) or experimental group (BWG; n=15). Baseline measures included disease severity (UPDRS III), global cognition (MoCA) and depression (PHQ-9). Outcome measures were selected gait variables on the 10m-instrumented-walk-test (i10mWT) assessed before and after the interventions. Both groups improved usual gait speed (FWG: p=0.03, d=0.35; BWG: p<0.01, d=0.35) and height-normalized gait speed (FWG: p=0.04, d=0.35; BWG: p<0.01, d=0.57). Additionally, the BWG demonstrated improved cadence (p<0.01, d=0.67) and stride length (SL; p=0.02, d=0.39). Both interventions were effective to improved gait speed sufficiently to independently navigate in the community.

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.

Analysis of the general match profile of international rugby union between 2007 and 2013

Abstract Law amendments are fundamental to the development of rugby and are introduced for a variety of reasons. The aim of this study was to investigate and compare the general match profile of international rugby between 2007 and 2013 in order to determine the effect of law changes. The researchers made use of mixed method methodology approach for this study. For the quantitative approach, a total of 248 matches were recorded and analyzed using the Fairplay video analysis software package. For the qualitative approach, the researchers conducted semi-structured interviews with expert coaches, specialist coaches, players and referees and referee coaches. The results revealed a practical significant decrease in the number of scrums (d = 1.03) line-outs (d = .86), rucks (d = .86), mauls (d = .62) and kicks (d = .46). An increase in the number of passes (d = .43), ball carries (d = 1.22) tackles attempted (d = .65) and penalty kicks (d = .98) between 2007 and 2013 was observed. The interviews revealed that under the current laws, there is an imbalance between attack and defence. The general match profile of international rugby has moved to a game with a decrease in the number of set pieces and kicks to an increase in the number of ball carries and tackles.

Scoring and general match profile of Super Rugby between 2008 and 2013

Rugby research has focused on a range of performance indicators related to game structures and tactical aspects. The purpose of this study was to investigate and compare the effect of law changes on the match profile of Super Rugby between the 2008 and 2013 seasons. For the purpose of this study the researchers made use of mixed-method methodology. A total of 646 Super Rugby matches were recorded and analyzed by means of the Fairplay video analysis software package. Further semi-structured interviews were conducted with expert coaches, specialist coaches, players and referees and referee coaches. Results revealed a significant increase in the number of points scored (p<0.01) and a decrease in the number of tries scored (p<0.01). Results of the study show that the profile of Super Rugby has changed to a more continuous game dynamic with the increase in the number of ball carries (d=1.34), passes (d=0.43), tackle breaks (d=1.59) and line breaks (d=2.40), and has led to an increase in the number of tackles (d=0.63). A decrease in the number of rucks (d=1.73), mauls (d=0.63), scrums (d=0.27) and scrum resets (d=1.36) was found. An increase in penalty kicks (d=2.04) and a decrease in free kicks (d=0.4.53) between 2008 and 2013 were observed. The general match profile of Super Rugby has moved to a game with fewer scrums and kicks and more ball carries and tackles. According to the interviewed experts, good playing surfaces in the Southern Hemisphere allow for an open-game approach by the teams.

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.