The impact of maturation level, not chronological age, on attentional control: implications for sports injury prevention in female adolescents.

BACKGROUND: Non-contact injuries are highly prevalent among young athletes and occur particularly in situations that require fast decision making and divided attention. Administering relevant neurocognitive tests could help identify deficiencies in these cognitive abilities and thus potentially mitigate injury risk. However, processes such as selective attention and response inhibition might depend to some extent on the athlete's maturation stage. We aimed to examine the effect of maturation on selective visual attention and response inhibition among adolescent volleyball players. METHODS: In this cross-sectional study, 52 female adolescents (age 12.3 ± 2.1 years) performed an Eriksen Flankers task. Participants were divided into subgroups based on their estimated adult stature, using the Khamis & Roche method: Pre-pubertal (PRE; n = 13, age: 9.9 ± 1.3), early-puberty (EPUB; n = 7, age: 10.5 ± 0.6), mid-puberty (MPUB; n = 8, age: 12.6 ± 0.8) and late puberty (LPUB; n = 24, age: 14.1 ± 0.9). Analyses of covariance (ANCOVA) were performed on congruent and incongruent reaction times (RT), with corresponding success rates (% correct responses) as covariate. Flanker interference effect was tested using ANOVA. Correlations were further examined between the dependent variables and participants' chronological age. RESULTS: There was a significant group effect, with PRE demonstrating longer RT compared with LPUB (P < 0.001) for both congruent and incongruent RT. Moderate negative correlations were observed between age and RT (Rp = -0.695, Rp = -0.614 for congruent and incongruent RT, respectively) and low positive correlations between age and incongruent success rate (Rs = 0.318). Low to moderate correlations were also observed within the LPUB group for RT (Rp = -0.431--0.532) and success rate (negative Rs = -574 for congruent and positive Rs = 0.417 for incongruent). There were no group differences nor age associations with interference effect. CONCLUSIONS: Our findings indicate that information processing and selective visual attention are superior at late maturation compared with early maturation among female adolescents. The same cannot be said for response inhibition, which did not differ between maturation groups. Similar tendencies were observed with regards to chronological age, but not entirely explained by it. Maturation level, rather than chronological age, should guide practitioners during sport participation and injury prevention programs for young athletes, whose neurocognitive abilities are not yet fully developed, placing them at risk for non-contact injuries.

External Focus of Attention Reduces Cartilage Load During Drop Landings.

The aim of the present study was to examine the effects of attentional focus instructions on acute changes in the transverse relaxation time (T2) of the femorotibial cartilage and in cartilage volume during repeated drop-jump landings. Ten healthy females (Mage = 20.4 ± 0.8 years) performed a drop landing task from a 50 cm high box over the course of 3 days (50 repetitions each day) across three attentional focus conditions: external focus (EF: focus on landing as soft as possible), internal focus (IF: focus on bending your knees when you land), and control (CON: no-focus instruction), which was counterbalanced across focus conditions. T2 mapping and the volume of femorotibial cartilage were determined from magnetic resonance imaging scans at 1.5 T for the dominant knee before and after completing the drop landings in each attentional focus condition per day. Results indicated a smaller change in cartilage T2 relaxation time and volumetry in the central load-bearing lateral cartilage under the EF, compared to IF and CON. Moreover, the change in T2 and cartilage volume was greater for lateral tibial cartilage as compared to femoral cartilage and was independent of attentional focus instructions. No significant acute quantitative changes were observed in the medial compartment. The peak vertical ground reaction force was found to be the lowest under the EF, compared to IF and CON. These findings suggest that external focus of attention may reduce cartilage load, potentially aiding in the control or management of cartilage injuries during landing in female athletes.

An external focus promotes motor learning of an aiming task in individuals with hearing impairments.

Research has shown that external relative to internal focus (IF) instructions may improve motor performance as well as cognitive function (e.g., attentional stability and task-focus). The aim of the study was to examine the influence of attentional focus instructions on skill acquisition and learning of an aiming task in individuals with hearing impairments. The participants (N = 39, Mage = 17.87 ± 1.88 years) performed a bowling task with their dominant hand to knock down as many pins as possible. On day 1, they were randomly divided into three attentional focus groups; IF (focus on your throwing hand), external focus (EF) (focus on the pins), and control (no-focus) instructions. Each participant performed 36 trials, divided into 3 blocks of 12 trials. Attentional focus instructions were given before each block, with a brief reminder provided after each 3 trials. On day 2, retention and transfer (further distance) tests were performed. Results showed that while there were no significant differences between groups in the pre-test, the EF group outperformed both IF and control groups in retention and transfer tests. No significant difference was found between the control and IF. The findings suggest that the advantages of the external relative to the IF and no-focus instructions may generalize to individuals with hearing impairments.

Response of Knee Joint Biomechanics to Landing Under Internal and External Focus of Attention in Female Volleyball Players.

The aim of this study was to examine the effect of attentional focus instructions on the biomechanical variables associated with the risk of anterior cruciate ligament injury of the knee joint during a drop landing task using a time series analysis. Ten female volleyball players (age: 20.4 ± 0.8 years, height: 169.7 ± 7.1 cm, mass: 57.6 ± 3.1 kg, experience: 6.3 ± 0.8 years) performed landings from a 50 cm height under three different attentional focus conditions: (1) external focus (focus on landing as soft as possible), (2) internal focus (focus on bending your knees when you land), and (3) control (no-focus instruction). Statistical parameter mapping in the sagittal plane during the crucial first 30% of landing time showed a significant effect of attentional focus instructions. Despite the similarity in landing performance across foci instructions, adopting an external focus instruction promoted reduced vertical ground reaction force and lower sagittal flexion moment during the first 30% of execution time compared to internal focus, suggesting reduced knee loading. Therefore, adopting an external focus of attention was suggested to reduce most biomechanical risk variables in the sagittal plane associated with anterior cruciate ligament injuries, compared to internal focus and control condition. No significant differences were found in the frontal and horizontal planes between the conditions during this crucial interval.

Motor-cognitive coupling is impaired in children with mild or severe forms of developmental coordination disorder.

Children with developmental coordination disorder (DCD) show deficits in motor-cognitive coupling. However, it remains unclear whether such deficits depend on the severity of DCD. The aim of this study was to examine cognitive-motor coupling under different levels of inhibitory control in children with severe (s-DCD) or moderate DCD (m-DCD), compared with typically-developing children (TDC). The performance of 29 primary-school children aged 6-12 years with s-DCD (Mage = 9.12 ± 1.56 years), 53 m-DCD (Mage = 8.78 ± 1.67 years), and 201 TDC (Mage = 9.20 ± 1.50 years) was compared on a double jump reaching task (DJRT) paradigm, presented on a large 42-inch touchscreen. The task display had a circular home-base, centred at the bottom of the display, and three target locations at radials of -20°, 0°, and 20°, 40 cm above the home-base circle. For the standard double-jump reaching task (DJRT), children moved their index finger from home-base circle to touch the target stimulus as fast as possible; 20% were jump trials where the target shifted left or right at lift-off. For the anti-jump reaching task (AJRT), 20% of trials required an anti-jump movement, touching the contralateral target location. While no group differences were shown on the DJRT, the DCD group were slower to complete reaching movements than the TDC group on AJRT; on the latter, the two DCD sub-groups were not shown to differ. Results confirm the presence of motor inhibition deficits in DCD which may not be dependent on the motor severity of the disorder.

Steady, Aim, Fire! Optimized Instructions Enhance Performance and Reduce Intra-Trial Variability in a Shooting Task.

The present study examined the influence of the individual and sequential combination of the key components of OPTIMAL (Optimizing Performance Through Intrinsic Motivation and Attention for Learning) theory (i.e., enhanced expectancies, autonomy support, and external focus), on the performance of a laser-pistol shooting task. In addition to shooting accuracy, intra-trial variability in the sway of forearm/pistol motion prior to movement execution (pulling the trigger) was the primary variable of interest. In a between-within-subject design, thirty-six participants (Mage = 21.27 ± 1.75 years) were randomized into either a control or an optimized group. Enhanced expectancies, autonomy support, and an external focus were implemented via sequential blocks of trials for participants in the optimized group. Participants in the control group performed all trials under "neutral" conditions. Our results showed that motor performance was enhanced for participants in the optimized group compared to those in the control group. Moreover, greater reductions in forearm sway leading up to the trigger pull were observed for the optimized group compared to the control group. These findings suggest higher movement effectiveness and efficiency, potentially through better attunement to task and environmental constraints, when implementing optimized instructions in a self-initiated fine motor task.

Behavioral and Neuroimaging Research on Developmental Coordination Disorder (DCD): A Combined Systematic Review and Meta-Analysis of Recent Findings.

AIM: The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD. METHODS: The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis. RESULTS: The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions. INTERPRETATION: Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier: CRD42020185444.

External focus of attention enhances arm velocities during volleyball spike in young female players.

The aim of this study was to investigate the effect of different volleyball-specific attentional focus instructions on arm velocities of a volleyball spike in young female volleyball players using the Statistical Parametric Mapping method. Twelve young female volleyball players (13.6 ± 0.6 years old, 1.8 ± 0.8 years of experience in volleyball training) were asked to perform a volleyball spike in a standing position in three different attentional focus conditions including internal focus (IF, i.e., pull back your elbow prior to transfer momentum), external focus, (EF, i.e., imagine cracking a whip to transfer momentum), and control (CON, i.e., no-focus instruction). A Qualisys 3D motion capture-system was used to track reflective markers attached to the arm, forearm, and hand. Consequently, four phases of the volleyball spike including wind-up, cocking, acceleration, and follow-through were analyzed. A one-way repeated-measure ANOVA using one-dimensional statistical parametric mapping (SPM1d) showed that players achieved greater velocities in the hand (p < 0.01), forearm (p < 0.01), and arm (p < 0.01) using the EF instructions from the start of the wind-up phase to the acceleration phase. Post-hoc (SPM1d-t-tests-paired) analyses indicated significantly greater arm, forearm, and hand velocities during the EF condition, compared to CON (p < 0.01, p < 0.01, and p < 0.01 respectively) and IF (p < 0.01, p < 0.01, and p < 0.01 respectively) conditions. These findings suggest that EF instructions had an immediate impact on increasing volleyball spike velocity from the start of the wind-up phase to the acceleration phase prior to ball contact.

More bang for the buck: autonomy support increases muscular efficiency.

The purpose of this study was to examine whether conditions that provide performers with a sense of autonomy, by giving them choices, would increase movement efficiency. We evaluated neuromuscular activation as a function of choice, using surface electromyography (EMG), during isometric force production. Participants (N = 16) were asked to perform plantar flexions at each of three target torques (80%, 50%, 20% of maximum voluntary contractions) under both choice and control conditions. In the choice condition, they were able to choose the order of target torques, whereas the order was pre-determined in the control condition. Results demonstrated that while similar torques were produced under both conditions, EMG activity was lower in the choice relative to the control condition. Thus, providing performers with a choice led to reduced neuromuscular activity, or an increase in movement efficiency. This finding is in line with the notion that autonomy support readies the motor system for task execution by contributing to the coupling of goals and actions (Wulf and Lewthwaite, Psychon Bull Rev 23:1382-1414, 2016).

Children's motor imagery modality dominance modulates the role of attentional focus in motor skill learning.

We investigated whether children's motor imagery dominance modulated the relationship between attentional focus and motor learning of a tossing task. One hundred and thirty-eight boys (age: M = 10.13, SD = 0.65) completed the Movement Imagery Questionnaire - Children (MIQ-C) to determine imagery modality dominance (kinesthetic, internal-visual, external-visual) and were randomly assigned to either an internal (n = 71) or external (n = 67) attentional focus group. Participants completed 60 trials of a tossing task with their non-dominant hand on day 1. Participants in the internal focus group were asked "to focus on the throwing arm", whereas participants in the external focus group were instructed "to focus on the ball." A retention test was conducted 24 h later to assess motor learning. Overall, the results from a nested, multiple linear regression analysis indicated the degree to which internal or external focus influences children's throwing accuracy is dependent upon their motor imagery modality dominance. Specifically, higher levels of external-visual imagery dominance resulted in greater motor learning for children adopting an external focus. In contrast, higher values of kinesthetic imagery dominance resulted in reduced motor learning for children who adopted an external focus. Despite the need for future research, we recommend motor imagery modality dominance assessments be considered when investigating the influence of attentional focus on motor learning, particularly when the target population is children.

The Effects of Attentional Focus Instruction on the Performance of a Whole-Body Coordination Task in Children With Developmental Coordination Disorder.

BACKGROUND AND AIM: Previous studies have supported the advantages of an external focus of attention (EFA) relative to an internal focus of attention (IFA) in healthly adults. However, effects of attentional focus instructions on skill performance and acquisition in children are equivocal. The aim of this study was to examine the effects of attentional focus instructions on performance of a whole body coordination task in children with and without developmental coordination disorder (DCD). METHODS: Children with DCD (n = 18) and typically developing (TD) children (n = 21) (9-10 years) were asked to perform 3 countermovement vertical jumps in the IFA (Concentrate on the swing of your arms), EFA (Concentrate on getting as close to the ceiling as possible), and control conditions. RESULTS: The results showed that regardless of children's motor development proficiency, the jump height and vertical take-off velocity (VTO) were higher in EFA relative to both IFA and Con conditions. In addition, VTO was significantly higher in the Con relative to IFA condition. CONCLUSION: The results of the current study showed that EFA relative to IFA instructions could enhance the neuromuscular activation of dynamic contractions of the leg muscles in both children with and without DCD. The findings suggest that the beneficial effects of EFA relative to IFA instructions on children's motor performance is identical across children with different levels of motor proficiency.

External relative to internal attentional focus enhances motor performance and learning in visually impaired individuals.

Background: Research has demonstrated the advantages of an external relative to internal focus of attention for enhancing motor performance and learning across diverse tasks, contexts and populations. However, research has yet to examine whether this finding holds true for individuals who have a major visual impairment in discrete and locomotion-based continuous motor tasks.Methods: In experiment 1, twenty-four visually impaired participants were asked to kick a soccer ball with their dominant foot to a target 7 meters away. Participants performed 10 trials within an internal focus (concentration on inside of the foot), external focus (concentration on the ball), and control (no focus instructions) conditions, in a counterbalanced order. In experiment 2, thirty-nine visually impaired adults were asked to ride a rehabilitation Pedalo for a distance of 7 meters. Participants were randomly assigned to either an internal focus (focus on the feet), external focus (focus on the platform), or control (no focus instructions) group. Retention and transfer tests were conducted on day 2.Results: An external focus resulted in more accurate kicks and faster pedalo movement times compared to an internal focus.Conclusions: These findings indicate that visual information does not mediate external focus benefits for motor performance and learning.Implications for RehabilitationPractitioners should use instructions that encourage visually impaired individuals who are going through rehabilitation to adopt an appropriate focus of attention for enhancing motor performance and learning of discrete or locomotion-based motor skills.Instructions that foster an external focus, relative to an internal focus, enhances performance of both discrete and continuous motor skills in individuals with visual impairment.

Practice variability promotes an external focus of attention and enhances motor skill learning.

Variability in practice has been shown to enhance motor skill learning. Benefits of practice variability have been attributed to motor schema formation (variable versus constant practice), or more effortful information processing (random versus blocked practice). We hypothesized that, among other mechanisms, greater practice variability might promote an external focus of attention on the intended movement effect, while less variability would be more conducive to a less effective internal focus on body movements. In Experiment 1, the learning of a throwing task was enhanced by variable versus constant practice, and variable group participants reported focusing more on the distance to the target (external focus), while constant group participants focused more on their posture (internal focus). In Experiment 2, golf putting was learned more effectively with a random compared with a blocked practice schedule. Furthermore, random group learners reported using a more effective distal external focus (i.e., distance to the target) to a greater extent, whereas blocked group participants used a less effective proximal focus (i.e., putter) more often. While attentional focus was assessed through questionnaires in the first two experiments, learners in Experiment 3 were asked to report their current attentional focus at any time during practice. Again, the learning of a throwing task was more effective after random relative to blocked practice. Also, random practice learners reported using more external focus cues, while in blocked practice participants used more internal focus cues. The findings suggest that the attentional foci induced by different practice schedules might be at least partially responsible for the learning differences.

Factorial Validity of the Movement Assessment Battery for Children-2nd Edition (MABC-2) in 7-16-Year-Olds.

The Movement Assessment Battery for Children-2nd Edition (MABC-2) is a test of motor development, widely used in clinical and research settings. To address which motor abilities are actually captured by the motor tasks in the two age versions of the MABC-2, the AB2 for 7- 10-year-olds and the AB3 for 11- 16-year-olds, we examined AB2 and AB3 factorial validity. We conducted confirmatory factor analysis (SPSS AMOS 22.0) on data from the test's standardization samples of children aged 7-10, n = 483, and 11-16, n = 674, in order to find the best fitting models. The covariance matrix of AB2 and AB3 fit a three-factor model that included tasks of manual dexterity, aiming and catching, and balance. However, factor analytic models fitting AB2 and AB3 did not involve the dynamic balance tasks of hopping with the better leg and hopping with the other leg; and the drawing trail showed very low factor validity. In sum, both AB2 and AB3 of the MABC-2 test are able to discriminate between the three specific motor abilities; but due to questionable psychometric quality, the drawing trail and hopping tasks should be modified to improve the construct validity for both age versions of the MABC-2.

Autonomy facilitates repeated maximum force productions.

Performer autonomy (or self-control) has consistently been shown to enhance motor learning, and it can also provide immediate benefits for motor performance. Autonomy is also a key variable in the OPTIMAL theory of motor learning (Wulf & Lewthwaite, 2016). It is assumed to contribute to enhanced expectancies and goal-action coupling, affecting performance effectiveness and efficiency. The purpose of the present study was to examine whether providing autonomy support by giving performers choices would enhance their ability to maintain maximum force levels. Participants were asked to repeatedly produce maximum forces using a hand dynamometer. After 2 initial trials with the dominant and non-dominant hand, stratified randomization was used to assign participants with the same average maximum force to one of two groups, choice or yoked control groups. Choice group participants were able to choose the order of hands (dominant, non-dominant) on the remaining trials (3 per hand). For control group participants, hand order was determined by choice-group counterparts. Maximum forces decreased significantly across trials in the control group, whereas choice group participants were able to maintain the maximum forces produced on the first trial. We interpret these findings as evidence that performer autonomy promotes movement efficiency. The results are in line with the view that autonomy facilitates the coupling of goals and actions (Wulf & Lewthwaite, 2016).

The Influence of Attentional Focus Instructions and Vision on Jump Height Performance.

PURPOSE: Studies have suggested that the use of visual information may underlie the benefit associated with an external focus of attention. Recent studies exploring this connection have primarily relied on motor tasks that involve manipulation of an object (object projection). The present study examined whether vision influences the effect of attentional focus on the performance of body movements through space (body projection). METHOD: Participants (N = 24, Mage = 25.0 ± 3.3 years) performed a maximum vertical jump in a room with a 4-m ceiling under full-vision and no-vision conditions. Additionally, participants performed 3 trials under each of 3 attentional conditions, presented in a counterbalanced order: external focus (ExF; "concentrate on the ceiling and try to touch it"), internal focus (InF; "concentrate on your fingers and try to bring them up as high as possible"), and control (Con; no-focus instruction). RESULTS: Results indicated that regardless of visual condition, a statistically significant difference was observed such that participants in the ExF condition (30.93 ± 8.37 cm) jumped significantly higher than participants in both the InF (30.09 ± 8.66 cm, p = .004, d = 0.68) and Con (30.23 ± 8.73 cm, p = .002, d = 0.57) conditions. Furthermore, jump height was overall significantly higher in the full-vision condition compared with the no-vision condition (p = .004, d = 0.47). Importantly, there was no interaction between ExF and vision. CONCLUSION: The present findings demonstrate the benefit of an ExF on a body projection task and further provide evidence of the independence of ExF and visual information.

Performance of gymnastics skill benefits from an external focus of attention.

The present study was designed to fill a gap in the literature on attentional focus and sports performance. Specifically, in contrast to most previous studies in which an external focus was directed at an implement, we used a gymnastics skill that did not involve the use of an implement. Furthermore, while most studies used only outcome measures of performance, we also assessed movement quality. Twelve-year-old gymnasts performed a maximum vertical jump with a 180-degree turn while airborne, with their hands crossing in front of their chest during the turn under three different focus conditions. Under the external focus condition, participants were asked to focus on the direction in which a tape marker, which was attached to their chest, was pointing after the turn. Under the internal focus condition, they were asked to focus on the direction in which their hands were pointing after the turn. Under the control condition, no focus instructions were given. The external focus condition resulted in both superior movement form and greater jump height than did the other two conditions, which produced comparable results. The present findings show that, similar to other tasks, the performance of form-based skills can be enhanced relatively easily by appropriate external focus instructions.