Soccer heading immediately alters brain function and brain-muscle communication

IntroductionThere is growing evidence of a link between repetitive soccer heading and the increased incidence of neurodegenerative disease. Even a short bout of soccer heading has been shown to impair cognitive performance and disrupt movement control. However, a greater understanding of the mechanisms behind these immediate impairments is needed. The current study attempted to identify how a short bout of soccer heading alters brain function and brain-muscle communication during a movement task.MethodsSixty soccer players were exposed to either an acute bout (i.e., 20 balls thrown underarm) of soccer heading (n = 30) or a control condition where participants (n = 30) headed soccer balls in virtual reality (VR). Before and after heading, we measured cognitive performance on the King-Devick test, as well as electromyography (EMG), electroencephalography (EEG) and brain-muscle communication (i.e., corticomuscular coherence; CMC) during a force precision task.ResultsFollowing the heading protocol, the VR group improved their cognitive performance whereas the Heading group showed no change. Both groups displayed more precise force contractions at post-test. However, the VR group displayed elevated frontal theta activity and global increases in alpha and beta activity during the contraction task, whereas the Heading group did not. Contrary to our expectations, the Heading group displayed elevated CMC, whereas the VR group showed no change.DiscussionOur findings indicate a short bout of soccer heading may impair cognitive function and disrupt the organization of efficient neural processes that typically accompany motor skill proficiency. Soccer heading also induced corticomuscular hyperconnectivity, which could represent compensatory brain-muscle communication and an inefficient allocation of increased task-related neuromuscular resources. These initial findings offer insights to the mechanisms behind the impairments experienced after a short bout of repetitive soccer heading

Testing the efficacy of a motor analogy designed to promote safe landing by older adults who fall accidentally: a study protocol for a randomised control study

Introduction: Falling is associated with adverse effects on the health of older people. The majority of research into falls among older people has focused on prevention, with less attention to ‘how to fall safely’. Previous research suggests that motor analogies can be used to promote safe landing by young adults; however, the efficacy of this technique for older people remains unknown. This study aims to determine whether a motor analogy is useful for promoting safe falling in the older adult population. Methods and analysis: The study adopts a randomised, controlled, single-blinded study design. People 65 years and older will be randomly allocated to a control condition or a motor analogy condition. They will receive a nudge in a forward, backward or sideways direction (randomised order), which will initiate a fall. The nudge will occur at variable (randomised) time points, so participants will not be aware of when they will fall. Participants in the motor analogy condition will be instructed to ‘land like a feather’, whereas participants in the control condition will be instructed to ‘land safely’. The primary outcome parameters are maximum impact force (normalised by mass) applied to different body segments during impact and fracture risk ratio of wrists and hips. A two-way multivariate analysis of variance will be conducted to examine differences between the motor analogy and control conditions as a function of the different variables. Ethics and dissemination: The University of Waikato Human Research Ethics Committee (Health 2021#45) has granted ethical approval. Outcomes will be disseminated through publication in peer-reviewed journals and presentations at conferences. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12621001189819. Registered on 6 September 2021

Inhibitory control, conscious processing of movement and anxiety

© 2019 Elsevier Ltd It has been suggested that a high propensity for reinvestment (i.e., conscious processing of movements) can disrupt performance, but the mechanisms responsible are not well understood. The purpose of this study was to examine whether people with superior inhibition function (i.e., ability to suppress unwanted thoughts and behaviours) were better able to suppress conscious processing of their movements (i.e., reinvestment). Inhibition function was assessed using a Go/NoGo button-press task, and individual propensity for reinvestment was assessed using the Movement Specific Reinvestment Scale (MSRS) and the Decision-Specific Reinvestment Scale (DSRS). The results revealed positive associations between inhibition function and reinvestment propensity, with better inhibition function evident in people who displayed a higher propensity to reinvest (MSRS and DSRS). Hierarchical regression analyses revealed that trait anxiety moderated the relationship between inhibition and movement specific reinvestment, with higher MSRS scores associated with better inhibition function in people with low trait anxiety. This association was not significant among people with high trait anxiety. Possible explanations for these results are discussed

Influence of an audience on conscious motor processing and performance during a go-only and stop-signal soccer penalty shooting task

The Theory of Reinvestment predicts that perceived pressure to perform well can negatively impact the perceptual-motor skills of experts, by promoting conscious reinvestment of explicit knowledge about how the skills should be performed (i.e., “conscious motor processing”). This study sought to investigate the influence of pressure on conscious motor processing and performance in a soccer (football) penalty shooting task. Performance was compared in an “execution-only” and “dynamic” task context, in which fifteen experienced soccer players were required to accurately shoot on target (execution-only) or, if the goalkeeper moved to intercept, inhibit their shot (dynamic). Pressure was manipulated by means of a small audience. Manipulation checks of conscious motor processing were taken, and performance measures included movement time, reaction time, inhibition success, and penalty shooting accuracy. Analyses indicated that penalty shooting accuracy was lower in the dynamic than in the execution-only task context (p = .01). Presence of an audience did not increase perceived anxiety, nor did it result in significant effects on conscious motor processing or penalty shooting performance. Covariate analyses identified trait reinvestment as a significant covariate. Whilst in general, presence of an audience had no significant effects on conscious motor processing or penalty shooting performance, high (trait) reinvestors were found to engage more in conscious motor processing, initiated their responses earlier (allowing more time for execution), and showed improved response inhibition in the presence of an audience. Future studies are required to further evaluate the influence of trait reinvestment on conscious motor processing and performance under pressure

Application of analogy learning in softball batting: Comparing novice and intermediate players.

Thisfield-based study developed and implemented analogy instructions for softballbatting, and examined batting performance outcomes. A focus-group discussioninvolving a coach and a number of team captains of a collegiate-level softball teamidentified the typical instructions used for batting (i.e., explicit) and developed ananalogy instruction that combined these rules in 1 biomechanical metaphor (i.e.,swing your bat like you are breaking a tree in front of you with an axe). A total of40 collegiate-level club players (20 novices and 20 intermediates) were assigned toeither an analogy learning or an explicit learning group and took part in 6 trainingsessions. Batting performance was assessed using a standardized criteria-basedrating scale in single-task pretest and posttest, and a dual-task test after training.The findings show that the novice, but not the intermediate players, displayedsignificant improvements in batting performance after training. Novices who re-ceived the analogy instruction displayed stable batting performance in the dual-tasktest, but novices who received explicit instructions, and intermediate players whoreceived the analogy instruction, displayed batting performance decrements. Thefindings suggest that the benefits of analogy instructions are evident only innovices; learners’ previous experiences must, therefore, be carefully consideredwhen developing coaching programs

The colour we wear: Impact on self-predicted and actual motor performance

The effect of colouron different aspects of performance has been the subject of substantial research interest, and red had been shown to have varying effects on not only performance, but perceptions as well. This study examined the effect of apparel colour on self-predicted and actual motor performance. Thirty-six young adults (18 females, 18 males; 20.4 SD 1.32 years old), who had no experience in football, performed a task consisting of an agility ladder drill and football shooting, in each of three bib colours (red, blue, black). Self-predicted and actual performances were measured on the dimensions of shooting accuracy and kicking power. A significant effect of colour on self-predicted shooting accuracy was found. Participants expected themselves to shoot less accurately when they were wearing a red bib, compared to when wearing blue and black bibs. No effect of colour on actual performance was found and no significant interaction was found between colour and sex. The findings suggest that wearing red could reduce users’ expectations of their performance in a novel motor task; there is no effect on actual performance

The effects of unilateral hand contractions on conscious control in early motor learning

Hemisphere asymmetry can be influenced by hand contractions. Brain imaging studies have indicated that pre-performance left-hand contractions may reduce verbal-analytical engagement in motor planning, whereas pre-performance right-hand contractions may increase verbal-analytical engagement in motor planning. This study examined whether a pre-performance left-hand contraction protocol reduced verbal-analytical engagement during practice of a golf putting task, thereby causing implicit motor learning. Forty-eight golf-novices were randomly allocated to left-hand contractions, right-hand contractions or no hand-contractions (control) groups. A line bisection task was conducted as a manipulation check of whether hemisphere asymmetry occurred. All participants practiced a golf putting task, with their allotted hand contraction protocol performed for 30 sec before every ten putts. Thereafter, participants completed two retention tests (blocks of single-task putting) before and after one transfer test (a block of dual-task putting). Different objective and subjective measures of verbal-analytical engagement were collected. Golf putting accuracy and kinematicswere assessed. Additionally, mood-state as a function of hemisphere asymmetry was measured. The line bisection task did not reveal a hemisphere asymmetry effect of the different hand contraction protocols. All groups equally improved during practice; however, the no hand-contraction (control) group showed better performance during both retention tests compared to left-hand and right-hand contraction groups. All groups performed worse in the dual-task transfer test. The objective and subjective measures of verbal-analytical engagement revealed no effect of hand contractions. General mood-state decreased for all groups from pre-to post-practice. Unilateral hand contractions prior to practicing the golf-putting task did not affect performance differently fromthe no hand-contraction (control) group. However, hand contractions resulted in worse performance compared to the no hand-contraction group during the retention tests, and dual-task transfer performance disrupted performance in all groups. No differences in verbal-analytical engagement were evident. Consequently, left-hand contractions did not promote implicit motor learning. Possible explanations and recommendations for future studies are discussed

A scoping review of the application of motor learning principles to optimize myoelectric prosthetic hand control.

Although prosthetic hand rejection rates remain high, evidence suggests that effective training plays a major role in device acceptance. Receiving training early in the rehabilitation process also enhances functional prosthetic use, decreases the likelihood of developing an overreliance on the intact limb, and reduces amputation-related pain. Despite these obvious benefits, there is a current lack of evidence regarding the most effective training techniques to facilitate myoelectric prosthetic hand control, and it remains unknown whether training is effective in facilitating the acquisition and transfer of prosthetic skill. In this scoping review, we introduced and summarized key motor learning principles related to attentional focus, implicit motor learning, training eye-hand coordination, practice variability, motor imagery, and action observation, and virtual training and biofeedback. We then reviewed the existing literature that has applied these principles for training prosthetic hand control before outlining future avenues for further research. The importance of optimizing early and appropriate training cannot be overlooked. While the intuition and experience of clinicians holds enormous value, evidence-based guidelines based on well-established motor learning principles will also be crucial for training effective prosthetic hand control. While it is clear that more research is needed to form the basis of such guidelines, it is hoped that this review highlights the potential avenues for this work

The role of conscious control in maintaining stable posture

© 2017 Elsevier B.V. This study aimed to examine the relationship between conscious control of movements, as defined by the Theory of Reinvestment (Masters & Maxwell, 2008; Masters, Polman, & Hammond, 1993), and both traditional and complexity-based COP measures. Fifty-three young adults (mean age = 20.93 ± 2.53 years), 39 older adults with a history of falling (mean age = 69.23 ± 3.84 years) and 39 older adults without a history of falling (mean age = 69.00 ± 3.72 years) were asked to perform quiet standing balance in single- and dual-task conditions. The results showed that higher scores on the Movement Specific Reinvestment Scale (MSRS; Masters, Eves, & Maxwell, 2005; Masters & Maxwell, 2008), a psychometric measure of the propensity for conscious involvement in movement, were associated with larger sway amplitude and a more constrained (less complex) mode of balancing in the medial–lateral direction for young adults only. Scores on MSRS explained approximately 10% of total variation in the medial–lateral sway measures. This association was not apparent under dual-task conditions, during which a secondary task was used to limit the amount of cognitive resources available for conscious processing. No relationship between postural control and score on the MSRS was found for either older adult fallers or non-fallers. Possible explanations for these results are discussed