Keith Lohse, Taylor Buchanan and Matthew Miller
Appropriate statistical analysis is essential for accurate and reliable research. Statistical practices have an immediate impact on the perceived results of a single study but also remote effects on the dissemination of information among scientists and the cumulative nature of research. To accurately quantify potential problems facing the field of motor learning, we systematically reviewed publications from seven journals over the past 2 years to find experiments that tested the effects of different training conditions on delayed retention and transfer tests (i.e., classic motor learning paradigms). Eighteen studies were included. These studies had small sample sizes (Mdn n/group = 11.00, interquartile range [IQR]= 9.6–15.5), multiple dependent variables (Mdn = 2, IQR = 2–4), and many statistical tests per article (Mdn = 83.5, IQR = 55.8–112.5). The observed effect sizes were large (d = 0.71, IQR = 0.49, 1.11). However, the distribution of effect sizes was biased, t(16) = 3.48, p < .01. These metadata indicate problems with the way motor learning research is conducted (or at least published). We recommend several potential solutions to address these issues: a priori power calculations, prespecified analyses, data sharing, and dissemination of null results. Furthermore, we hope these data will spark serious action from all stakeholders (researchers, editorial boards, and publishers) in the field.
Floor Morriën, Matthew J. D. Taylor and Florentina J. Hettinga
To provide an overview of biomechanical studies in Paralympic research and their relevance for performance in Paralympic sports.
The search terms paralympic biomechanics, paralympic sport performance, paralympic athlete performance, and paralympic athlete were entered into the electronic database PubMed.
Thirty-four studies were found. Biomechanical studies in Paralympics mainly contributed to performance enhancement by technical optimization (n = 32) and/or injury prevention (n = 6). In addition, biomechanics was found to be important in understanding activity limitation caused by various impairments, which is relevant for evidence-based classification in Paralympic sports (n = 6). Distinctions were made between biomechanical studies in sitting (41%), standing (38%), and swimming athletes (21%). In sitting athletes, mostly kinematics and kinetics in wheelchair propulsion were studied, mainly in athletes with spinal-cord injuries. In addition, kinetics and/or kinematics in wheelchair basketball, seated discus throwing, stationary shot-putting, hand-cycling, sit-skiing, and ice sledge hockey received attention. In standing sports, primarily kinematics of athletes with amputations performing jump sports and running and the optimization of prosthetic devices were investigated. No studies were reported on other standing sports. In swimming, mainly kick rate and resistance training were studied.
Biomechanical research is important for performance by gaining insight into technical optimization, injury prevention, and evidence-based classification in Paralympic sports. In future studies it is advised to also include physiological and biomechanical measures, allowing the assessment of the capability of the human body, as well as the resulting movement.
Marcos Daou, Taylor L. Buchanan, Kyle R. Lindsey, Keith R. Lohse and Matthew W. Miller
There is some evidence that people learn academic (declarative) information better when studying with the expectation of having to teach, but this has not been demonstrated for perceptual-motor skills, which also rely on declarative information but more heavily on procedural knowledge. To address this possibility, participants studied golf-putting instructions and practiced putting with the expectation of having to teach another participant how to putt or the expectation of being tested on their putting. One day later, learning was assessed by testing all participants on their golf putting. Results revealed that expecting to teach enhanced learning, even after controlling for the amount of studying and practicing. Therefore, we have presented the first findings that expecting to teach enhances motor learning. Taking these findings together with similar studies focusing on declarative information, we suggest that expecting to teach yields a general learning benefit to different types of skills.
Matthew J. Taylor, Rachel A. Wamser, Michelle E. Sanchez and Charleanea M. Arellano
The purpose of this study was to explore the impact of sports participation and race/ethnicity on violence and victimization among a sample of white, African American, and Hispanic rural-area high school girls. It was hypothesized that girls who participated in sports would report lower rates of violent behavior and fewer incidents of victimization. Using logistic regression and multivariate analysis of variance, evidence for the hypotheses was mixed and appeared to be related to the type of violence and victimization. Sports participants were less likely to engage in general violence and reported less physical and sexual victimization, but did not experience less intimate partner violence victimization. Conversely, sports participants were more likely to engage in verbal and physical reactive violence. While sports participation may have some preventative impact on violence and victimization, this relationship may also be influenced by community characteristics and not a universal outcome.
Jonathan M. Taylor, Tom W. Macpherson, Shaun J. McLaren, Iain Spears and Matthew Weston
To compare the effects of 2 repeated-sprint training programs on fitness in soccer.
Fifteen semiprofessional soccer players (age: 24 ± 4 y; body mass: 77 ± 8 kg) completed 6 repeated-sprint training sessions over a 2-week period. Players were assigned to a straight-line (STR) (n = 8; 3–4 sets of 7 × 30 m) or change of direction (CoD) (n = 7; 3–4 sets of 7 × 20-m) repeated-sprint training group. Performance measures included 5-, 10-, and 20-m sprints, countermovement jump, Illinois agility, and Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1) performance. Internal (heart rate) and external (global positioning system-derived measures) training loads were monitored throughout. Data were analyzed using magnitude-based inferences.
Internal and external loads were higher in the STR group than in the CoD group with large differences in maximum velocity (28.7%; ±90% confidence limits, 3.3%), moderate differences in mean heart rates (7.0%; ±1.4%) and PlayerLoad (17.6%; ±8.6%), and small differences in peak heart rates (3.0%; ±1.6%). Large improvements in 5-m (STR: 9.6%; ±7.0% and CoD: 9.4%; ±3.3%), 10-m (STR: 6.6%; ±4.6% and CoD: 6.7%; ±2.2%), and 20-m (STR: 3.6; ±4.0% and CoD: 4.0; ±1.7%) sprints were observed. Large and moderate improvements in YYIRTL1 performance were observed in the STR (24.0%; ±9.3%) and CoD (31.0%; ±7.5%), respectively. Between-groups differences in outcome measures were unclear.
Two weeks of repeated-sprint training stimulates improvements in acceleration, speed, and high-intensity running performance in soccer players. Despite STR inducing higher internal and external training loads, training adaptations were unclear between training modes, indicating a need for further research.
Jonathan M. Taylor, Tom W. Macpherson, Iain R. Spears and Matthew Weston
The ability to repeatedly perform sprints has traditionally been viewed as a key performance measure in team sports, and the relationship between repeated-sprint ability (RSA) and performance has been explored extensively. However, when reviewing the repeated-sprint profile of team-sports match play it appears that the occurrence of repeated-sprint bouts is sparse, indicating that RSA is not as important to performance as commonly believed. Repeated sprints are, however, a potent and time-efficient training strategy, effective in developing acceleration, speed, explosive leg power, aerobic power, and high-intensity-running performance—all of which are crucial to team-sport performance. As such, we propose that repeated-sprint exercise in team sports should be viewed as an independent variable (eg, a means of developing fitness) as opposed to a dependent variable (eg, a means of assessing fitness/performance).