The Effects of Three Correction Strategies of Errors on the Snatch Technique in 10-12-Year-Old Children: A Randomized Controlled Trial.

ABSTRACT: Souissi, MA, Elghoul, Y, Souissi, H, Masmoudi, L, Ammar, A, Hamdi Chtourou, and Souissi, N. The effects of three corrections strategies of errors on the snatch technique in 10-12-year-old children: A randomized controlled trial. J Strength Cond Res 37(6): 1218-1224, 2023-Sports movement correction is one of the major problems for motor control and learning. Therefore, the purpose of the present study was to determine which of the 3 strategies, i.e., the self-observation method with direct instructions (SO-DI), self-observation alone (SO), or the direct instruction (DI), would be useful for correcting errors during the snatch technique. Forty-eight children with 2 months of experience were randomly assigned to one of 4 training conditions: SO-DI, SO, DI, or control. In this study, the experience lasted 15 sessions. Subjects completed the test sessions before (T 0 ) and after (T 1 ) 12 training sessions and a retention test session after 2 weeks (T 2 ). The Kinovea version 0.8.15 software was used to measure the kinematic parameters of weightlifting performance. After the training intervention, the data showed that the SO-DI group registered a greater improvement in all kinematic parameters compared with the SO, DI, and control groups, and this benefit was present 2 weeks later in the retention test (e.g., the horizontal displacement of the bar in the first pull with respect to the starting position [T1 vs. T0: +32.57 ± 6.69%, d = 1.87, p < 0.001; T2 vs. T0: 25.07 ± 11.55%, d = 1.32, p < 0.001] and the horizontal displacement of the bar between the receiving position and the reference line [T1 vs. T0: 24.34 ± 29%, d = 1.17, p < 0.01; T2 vs. T0: 25.53 ± 30.4%, d = 0.99, p < 0.01]). The results of the present study could have practical implications for physical education teachers because, even if practice is required to improve the technique, the effectiveness of the learning process is essential to enhance learner self-efficacy and motivation.

Bilateral Training Improves Agility and Accuracy for Both Preferred and Non-Preferred Legs in Young Soccer Players.

As laterality of the lower limbs is regarded as a relevant influence on soccer performance, we assessed whether a bilateral training program for both the preferred leg (PL) and non-preferred leg (NPL) would improve soccer players' lateral asymmetry, agility, and accuracy. Sixty right-foot-dominant young soccer players were randomly assigned to either an experimental group (EXP) that underwent bilateral training or a control group (CONT) that performed their usual training schedule without bilateral exercise. We assessed the players' lateral asymmetries before and after training on four soccer skill tasks: a zigzag test with and without a ball, a receiving and direct volley-shooting accuracy test, and a passing accuracy test. Results showed post-test versus pre-test performance improvements for the EXP group on the index of technical skills and agility (p < .001). A post-hoc analysis further revealed a pre-test to post-test performance improvement on shooting and passing accuracy with both legs only for the EXP group (p < .001). These results support the role of bilateral practice in improving lateral asymmetries, agility, and accuracy.

The Effect of an 8-Week Aerobic Dance Program on Executive Function in Children.

In the current study, we examined the effect of an aerobic dance program as part of physical education (PE) classes on aspects of primary school children's executive functions (EFs) (inhibition, working memory, and cognitive flexibility). Participants were 41 children (21 boys and 20 girls; M age =10.30, SD = 0.50 years, M height = 134.09, SD= 3.9 cm; M weight = 35.61, SD = 7.85 kg) who were divided into an experimental group (EG) and a no-PE control group (CG). The EG followed an aerobic dance intervention as part of their PE program (45 minute sessions two days per week over eight weeks). Participants in both groups performed EF tests before and after the intervention period to evaluate their mental flexibility, inhibition, and working memory. A two-way mixed model repeated measures ANOVA revealed a significant effect of the aerobic dance program on participants' cognitive flexibility (i.e., on Trails Making Tests B-A times and committed errors) (p <0.001), and on Stroop measures of inhibition (corrected number of words and corrected errors) (p <0.001 and p <0.01, respectively), with post-hoc analyses showing an improved performance by the EG in working memory (digit recall score) from pre-test to post-test and in comparsion to the CG (p < 0.001). Thus, this 8-week aerobic dance program promoted EF development among primary school children.

Optimizing Motor Learning: Difficulty Manipulation Combined with Feedback- Frequency Enhance Under-Time-Pressure Fine-Motor-Coordination Skill Acquisition and Retention.

Improving acquisition and retention of new motor skills is of great importance. This study investigated the effects of progressive task difficulty manipulation (TD), combined with varying knowledge of results frequencies (KR) on performance accuracy and consistency when learning novel fine motor coordination tasks, and examined relationships between novel fine motor task performance and executive function (EF), working memory (WM), and perceived difficulty (PD). Thirty-six, right-handed, novice physical-education students (age = 10.72 ± 0.89 years) participated; participants were separated into three groups, receiving varying KR frequency (100%KR, 50%KR, and 33%KR). For each group, distance to the target was increased progressively (2 m, 2.37 m, and 3.56 m) to obtain three difficulty levels. We assessed performance during test sessions (pretest, post-test, Retention1 and Retention2) under free (FC) and time pressure (TPC) conditions. Results revealed that under FC, 100%KR improved significantly. Results revealed significant linear improvements in accuracy for 50%KR and 33%KR under TPC. New findings indicate that the association between TD and KR (50%KR) may provide more appropriate cognitive loads compared to 33%KR and 100%KR groups. These have implications for practitioners because, while strategies are clearly necessary for improving learning, the efficacy of the process appears to be based on the characteristics of the learners.

The Effects of Manipulating Task Difficulty and Feedback Frequency on Children's Dart Throwing Accuracy and Consistency.

In the present study we investigated the effects of manipulating task difficulty (constant vs. progressive difficulty) and frequency of knowledge of results (KR) on the accuracy and consistency of children's performance of a novel fine motor coordination task (dart throwing). We assigned 69 right-handed physical education (PE) students (M age = 10.73, SD = 0.89 years) to progressive (PDG) or constant difficulty (CDG) groups. PDG and CDG were each split into three subgroups who received varying KR frequency (100%KR, 50%KR, and 33%KR), creating a total of six groups. We increased difficulty in the PDG by manipulating the distance to the target (2 m, 2.37 m, and 3.56 m), while distance to the target was constant for CDG throughout the experiment (2.37 m). We conducted performance assessments during familiarization (pre-test), acquisition (post-test), and retention (retention testing) learning phases under both normal condition (NC) and a time pressure condition (TPC). Repeated-measures analysis of variance revealed a significant effect of difficulty manipulation on skill learning under both NC and TPC. Further analyses revealed that skill learning was enhanced by progressive difficulty manipulation. However, learning was not affected by KR frequency changes. Progressive difficulty practice enhanced both accuracy and consistency, specifically at retention testing. These results suggest that motor learning in children may be enhanced by practicing with progressive increases in difficulty. PE teachers are encouraged to gradually introduce difficulty levels in motor learning tasks that require high accuracy.

Information Processing and Technical Knowledge Contribute to Self-Controlled Video Feedback for Children Learning the Snatch Movement in Weightlifting.

Our aim in this study was to examine, via technical performance analysis and speed of execution, whether information processing and technical knowledge help explain learning benefits of self-controlled video feedback in children's weightlifting performance. We randomized 24 children (aged 10 to 12 years) into self-controlled (SC) and yoked (YK) feedback groups. Learners underwent test sessions one week before (pre-test) and one day after (post-test) six weightlifting training sessions. During each test session, we recorded kinematic parameters of snatch performance using Kinovea version 0.8.15 software. After the learning sessions, the SC group improved on most kinematic parameters (e.g., the horizontal displacement of the bar between the first and the second pulls [MDXV = 25.42%, SD = 18.96, p = 0.003) and the maximum height reached by the bar (MHMV = 5.51%, SD = 7.71, p < 0.05)], while the YK group improved only on the DxV (MDXV = 19.08%, SD = 24.68, p < 0.05). In addition, the SC group showed a more advanced phase of cognitive processing compared to the YK group, and the SC group showed a superior improvement in their technical knowledge level (p < 0.001) compared to the YK group (p < 0.05). Thus, key elements to correcting motor errors in children's weightlifting through self-controlled feedback were improvements in information processing and technical knowledge.

Sleep Quality and Physical Activity as Predictors of Mental Wellbeing Variance in Older Adults during COVID-19 Lockdown: ECLB COVID-19 International Online Survey.

BACKGROUND: The COVID-19 lockdown could engender disruption to lifestyle behaviors, thus impairing mental wellbeing in the general population. This study investigated whether sociodemographic variables, changes in physical activity, and sleep quality from pre- to during lockdown were predictors of change in mental wellbeing in quarantined older adults. METHODS: A 12-week international online survey was launched in 14 languages on 6 April 2020. Forty-one research institutions from Europe, Western-Asia, North-Africa, and the Americas, promoted the survey. The survey was presented in a differential format with questions related to responses "pre" and "during" the lockdown period. Participants responded to the Short Warwick-Edinburgh Mental Wellbeing Scale, the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and the short form of the International Physical Activity Questionnaire. RESULTS: Replies from older adults (aged >55 years, n = 517), mainly from Europe (50.1%), Western-Asia (6.8%), America (30%), and North-Africa (9.3%) were analyzed. The COVID-19 lockdown led to significantly decreased mental wellbeing, sleep quality, and total physical activity energy expenditure levels (all p < 0.001). Regression analysis showed that the change in total PSQI score and total physical activity energy expenditure (F(2, 514) = 66.41 p < 0.001) were significant predictors of the decrease in mental wellbeing from pre- to during lockdown (p < 0.001, R2: 0.20). CONCLUSION: COVID-19 lockdown deleteriously affected physical activity and sleep patterns. Furthermore, change in the total PSQI score and total physical activity energy expenditure were significant predictors for the decrease in mental wellbeing.

Effects of Combined Versus Singular Verbal or Haptic Feedback on Acquisition, Retention, Difficulty, and Competence Perceptions in Motor Learning.

While augmented feedback (AF) is widely acknowledged to affect motor learning, the effects of mode of feedback on motor learning acquisition, retention, and perceived competence has rarely been studied. The present investigation analyzes the effects of verbal, haptic, and combined (verbal and haptic) feedback when learning a novel gymnastic parallel bars task. Forty-eight physical education students and four expert gymnastics teachers participated in the study. We divided the students into three AF groups (verbal, haptic, and combined) and a no-feedback control group (CG). One gymnastics teacher led the learning sessions, while the others evaluated student performances following familiarization, acquisition, and retention learning phases. All sessions were video recoded, and the experts gave blind assessments according to an adapted gymnastic point code. We recorded task perceived difficulty (PD) and students' perceived self-competency throughout the sessions. A repeated measures analysis of variance revealed a significant effect of AF mode on acquisition and retention such that combined AF was best for learning stability and retention (19.1% improvement for combined vs. 9.9% for haptic and 6.9% for verbal). Similarly, participants in the combined AF group, relative to the verbal and haptic AF groups, also reported lower perceived difficulty and higher perceived self-competency after the retention phase. PE teachers are encouraged to combine verbal and haptic AF when teaching new motor skills.

Acute effect of stretching modalities and time-pressure on accuracy and consistency of throwing darts among 12- and 13-year-old schoolboys.

BACKGROUND: The present study addressed the lack of data on the effect of different types of stretching on selected measures of throwing accuracy. We hypothesized that the stretching procedures, within pre-exercise warm-up, could affect the accuracy and the consistency in throwing darts performances under different stress conditions. METHODS: Eighteen right-handed schoolboys (13.1±0.4 years, 166±0.1 cm and 54.5±9 kg; mean±SD) completed the Darts Throwing Accuracy Test in free (FDT) and in time-pressure (TPDT) conditions, either after static (SS), dynamic (DS), ballistic (BS) or no-stretching (NS) protocols, on nonconsecutive days and in a counter-balanced randomized order. After performing 5 minutes of light standardized jogging and one of the three stretching protocols for 10 minutes, each participant completed the FDT and TPDT tests. Mean scores, missed darts and variability of scores, were recorded and analyzed using a two-way ANOVA with repeated measures. Heart rate (HR), ratings of perceived exertion (RPE) and the task difficulty perception (DP), were recorded through each experimental session. RESULTS: There was no effect of the stretching procedures on accuracy in FDT. However, in the TPDT condition, better performances were recorded after NS and SS compared to DS and BS. The accuracy performances decreased in TPDT by 9.6% after NS (P<0.01); 15.3% after DS (P<0.001) and 11.8% after BS (P<0.001); but not after SS (P<0.05). CONCLUSIONS: Static stretching helped reducing the adverse effects of time-pressure on darts throwing performance. Consequently, static exercises are recommended before practicing activities requiring both upper limbs speed and accuracy.