Kicking performance in relation to balance ability over the support leg

A Systematic review of the factors that affect soccer players' short-passing ability-based on the Loughborough Soccer Passing Test

OBJECTIVE

This study synthesizes evidence from the Loughborough Passing Test to evaluate the short-passing ability of soccer players and summarizes the reported variables that affect this ability to provide support for the development and improvement of short-passing abilities in soccer players.

METHODS

In this systematic review using the PRISMA guidelines, a comprehensive search was conducted in Web of Science, PubMed, and EBSCOhost from inception to July 2023 to identify relevant articles from the accessible literature. Only studies that used the Loughborough test to assess athletes' short-passing ability were included. The quality of the included studies was independently assessed by two reviewers using the PEDro scale, and two authors independently completed the data extraction.

RESULTS

Based on the type of intervention or influencing factor, ten studies investigated training, nine studies investigated fatigue, nine studies investigated supplement intake, and five studies investigated other factors.

CONCLUSION

Evidence indicates that fitness training, small-sided games training, and warm-up training have positive effects on athletes' short-passing ability, high-intensity special-position training and water intake have no discernible impact, mental and muscular exhaustion have a significantly negative effect, and the effect of nutritional ergogenic aid intake is not yet clear. Future research should examine more elements that can affect soccer players' short-passing ability.

TRIAL REGISTRATION

https://inplasy.com/ ., identifier: INPLASY20237.

Anticipatory postural control in adaptation of goal-directed lower extremity movements

Skilled football players can adapt their kicking movements depending on external environments. Predictive postural control movements, known as anticipatory postural adjustments (APAs), are needed preceding kicking movements to precisely control them while maintaining a standing posture only with the support leg. We aimed to clarify APAs of the support leg in the process of adaptation of goal-directed movements with the lower limb. Participants replicated ball-kicking movements such that they reached a cursor, representing a kicking-foot position towards a forward target while standing with the support leg. APAs were observed as the centre of pressure of the support leg shifted approximately 300 ms in advance of the onset of movement of the kicking foot. When the cursor trajectory of the kicking foot was visually rotated during the task, the kicking-foot movement was gradually modified to reach the target, indicating adaptation to the novel visuomotor environment. Interestingly, APAs in the mediolateral direction were also altered following the change in kicking-foot movements. Additionally, the APAs modified more slowly than the kicking-foot movements. These results suggest that flexible changes in predictive postural control might support the adaptation of goal-directed movements of the lower limb.

The Effect of a Balance Training Program on the Balance and Technical Skills of Adolescent Soccer Players

Soccer is a complex sport, and balance appears to play a crucial role in the quality execution of technical skills, which are mostly performed while standing on one foot. Nevertheless, in younger ages, when learning still affects soccer performance, the effect of a balance-training program on the player's balance and technical skills remains unexplored. This research examined the effect of a balance-training program (BTP) on balance and technical skills of adolescent soccer players. Τhe participating volunteers were thirty-two soccer players (12-13 years old with 3.84 ± 0.95 years of practice), randomly separated into two groups: an experimental (EXP, n1 = 17) and a control group (CON, n2 = 15). Both groups were evaluated in static and dynamic balance and in technical skills (dribbling, passing, juggling, and shooting with dominant and non-dominant legs) before (Pre-condition) and after the intervention (Post-condition) which was an eight-week BTP for the EXP group and a placebo-training program for the CON group. Α 2 by 2 (groups×condition) mixed analysis of variance (ANOVA) with repeated measures on the condition factor was used to assess possible differences between groups. A significant groups × condition interaction effect was found in dynamic balance (p = 0.008), static (p = 0.042), and shooting (p = 0.022) with dominant leg performance. The EXP group improved (p = 0.007) its static balance by 37.82% and also significantly improved its dynamic balance and shooting accuracy with dominant leg in Post condition by 24.98% (p = 0.006) and 83.84% (p = 0.006) respectively. No significant improvement of other variables was detected in the EXP group Post condition. Dynamic and static balance, and shooting with dominant leg skills can be improved in adolescent soccer players through a specialized 8-week BTP. Balance-training program may contribute to technical skill improvement in soccer training.

Leg and Joint Stiffness of the Supporting Leg during Side-Foot Kicking in Soccer Players with Chronic Ankle Instability

Soccer players with chronic ankle instability (CAI) may stabilize their supporting leg by the proximal joint to compensate for the ankle instability during kicking motion. This study aimed to investigate the characteristics of leg and joint stiffness of the supporting leg during side-foot kicking in soccer players with CAI. Twenty-four male collegiate-level soccer players with and without CAI participated in this study. The kinematic and kinetic data were obtained using a three-dimensional motion analysis system. Leg stiffness and joint (hip, knee, and ankle) stiffness in the sagittal and frontal planes were calculated and analyzed. The results clarified that soccer players with CAI (0.106 ± 0.053 Nm/°) had greater knee stiffness in knee adduction during the kicking cycle compared to those without CAI (0.066 ± 0.030 Nm/°; p = 0.046), whereas no characteristic differences were observed in knee stiffness in knee flexion and hip and ankle stiffness (p > 0.05). Knee stiffness is believed to occur to compensate for ankle joint instability in the supporting leg. Therefore, adjusting knee stiffness to accommodate ankle joint instability is crucial for maintaining kicking performance. Based on results of this study, it may be important to consider training and exercises focused on joint coordination to improve knee stiffness in soccer players with CAI.

Analysis of technical characteristics of typical lower limb balance movements in Tai Chi: a cross-sectional study based on AnyBody bone muscle modeling

BACKGROUND

Tai Chi is an excellent traditional Chinese physical fitness exercise, and its unique balancing movements are very important for improving human balance. In this study, the two most representative Tai Chi balance movements, "knee lift balance" and "leg stirrup balance", were selected to establish the lower limb bone muscle model of Tai Chi balance movements by using computer simulation modeling technology, aiming to analyze the characteristics of the lower limb movement mechanisms of typical balance movements, to provide a quantitative theoretical basis for improving the scientific level of Tai Chi.

METHOD

A total of 16 subjects were recruited for this study. the BTS three-dimensional motion capture system and three-dimensional force platform were used for motion data acquisition, the physiological electromyographic signals were collected using BTS surface electromyography, and the lower limb bone muscle model of Tai Chi balance movements was established by AnyBody human simulation.

RESULT

In the knee lift balancing movement, the balance leg hip abduction/adduction angle, hip flexion/extension moment, and the strength of the rectus femoris muscle, biceps femoris short capitis, and iliacus muscle of the amateur group was significantly smaller than that of the professional group (P < 0.01). In the leg stirrup balance movement, the knee flexion/extension angle of the balancing leg in the amateur group was significantly greater than that in the professional group (P < 0.01), and the hip flexion/extension angle, hip inversion/abduction angle, knee flexion/extension moment, hip flexion/extension moment, the strength iliacus, gluteus maximus, and obturator internus were significantly smaller than those in the professional group (P < 0.01). The integral EMG of the biceps femoris of the support leg in the amateur group was significantly smaller than that of the professional group (P < 0.01). The integral EMG of the lateral femoral muscle of the balance leg was significantly smaller than that of the professional group (P < 0.01).

CONCLUSION

In this study, we found that the balancing leg of the balancing movement has a larger hip joint angle, the stirrup balancing knee joint angle is smaller, and the hip and knee joint moments are larger. This is related to joint activity and muscle activation, and amateurs should pay attention to increasing the range of motion of the hip joint and decreasing the range of motion of the knee joint when practicing to better stimulate exercise of the lower limb joints. In addition, the practice of balancing movements should strengthen the iliacus muscle, which plays an important role in maintaining the stable balance of the lower limbs, and strengthen the knee flexor and extensor muscles and hip adductor/abductor muscles of the balancing leg, thus promoting the stability of the balancing leg movements.

Effects of plyometric training on technical skill performance among athletes: A systematic review and meta-analysis

BACKGROUND

The literature has proven that plyometric training (PT) improves various physical performance outcomes in sports. Even though PT is one of the most often employed strength training methods, a thorough analysis of PT and how it affects technical skill performance in sports needs to be improved.

METHODS

This study aimed to compile and synthesize the existing studies on the effects of PT on healthy athletes' technical skill performance. A comprehensive search of SCOPUS, PubMed, Web of Science Core Collection, and SPORTDiscus databases was performed on 3rd May 2023. PICOS was employed to establish the inclusion criteria: 1) healthy athletes; 2) a PT program; 3) compared a plyometric intervention to an active control group; 4) tested at least one measure of athletes' technical skill performance; and 5) randomized control designs. The methodological quality of each individual study was evaluated using the PEDro scale. The random-effects model was used to compute the meta-analyses. Subgroup analyses were performed (participant age, gender, PT length, session duration, frequency, and number of sessions). Certainty or confidence in the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

Thirty-two moderate-high-quality studies involving 1078 athletes aged 10-40 years met the inclusion criteria. The PT intervention lasted for 4 to 16 weeks, with one to three exercise sessions per week. Small-to-moderate effect sizes were found for performance of throwing velocity (i.e., handball, baseball, water polo) (ES = 0.78; p < 0.001), kicking velocity and distance (i.e., soccer) (ES = 0.37-0.44; all p < 0.005), and speed dribbling (i.e., handball, basketball, soccer) (ES = 0.85; p = 0.014), while no significant effects on stride rate (i.e., running) were noted (ES = 0.32; p = 0.137). Sub-analyses of moderator factors included 16 data sets. Only training length significantly modulated PT effects on throwing velocity (> 7 weeks, ES = 1.05; ≤ 7 weeks, ES = 0.29; p = 0.011). The level of certainty of the evidence for the meta-analyzed outcomes ranged from low to moderate.

CONCLUSION

Our findings have shown that PT can be effective in enhancing technical skills measures in youth and adult athletes. Sub-group analyses suggest that PT longer (> 7 weeks) lengths appear to be more effective for improving throwing velocity. However, to fully determine the effectiveness of PT in improving sport-specific technical skill outcomes and ultimately enhancing competition performance, further high-quality research covering a wider range of sports is required.

Lower Quarter Y-Balance Test Anterior Reach Asymmetry and Noncontact Lower Limb Injury in Subelite Young Male Soccer Players With Different Training Experiences

Poor single-leg balance performance is associated with an increased risk of sustaining lower limb injuries in team sports. However, it is unclear whether this relationship is modified by the level of training experience (years of training experience). The objective of the present study was to evaluate whether soccer players’ single-leg balance performance is related to lower limb injuries in noncontact situations with different levels of training experience. Subelite young male soccer players performed the Lower Quarter Y-Balance Test with the dominant and the nondominant leg at the beginning of the preseason. Due to COVID-19 rules, the occurrence of lower limb injuries during the second half of the competitive season was documented. The odds of injury were calculated based on a previously reported Lower Quarter Y-Balance Test cut-off score for side-to-side anterior reach difference (≥4 cm). Twelve soccer players sustained a lower leg injury in noncontact situations. Only four of them had an anterior reach difference equal to or above the cut-off score. Soccer training experience has no significant influence on the association between Lower Quarter Y-Balance Test anterior reach asymmetry and noncontact lower limb injury in young male players.

Biomechanical Characteristics of the Support Leg During Side-Foot Kicking in Soccer Players With Chronic Ankle Instability

Background:

Chronic ankle instability (CAI) in soccer players can increase the risk of recurrent ankle varus sprains and damage the articular surface of the ankle joint, thus increasing the risk of osteoarthritis. It is important to understand the biomechanical characteristics of the support leg during kicking in soccer players with CAI.

Purpose/Hypothesis:

The purpose of this study was to clarify the kinematics of the kicking motion of soccer players with CAI. It was hypothesized that at the point before ball contact when the support leg makes flat-foot contact with the ground, soccer players with CAI will land with ankle inversion in the support leg during a side-foot kick compared with players without CAI.

Study Design:

Controlled laboratory study.

Methods:

The study cohort included 19 male college soccer players (mean age, 20.5 ± 0.9 years) with greater than 8 years of soccer experience who were recruited from August 2019 to March 2020. Of these athletes, 10 had CAI and 9 had no CAI in the support leg, as diagnosed according to the Cumberland Ankle Instability Tool. Kinematic data for the trunk, hip, knee, and foot of the support leg during a side-foot kick were obtained using a 3-dimensional, motion-analysis system. The Mann-Whitney U test or Student t test was selected to identify differences in variables between the CAI and non-CAI groups.

Results:

There were no significant differences in physical characteristics between the CAI and non-CAI groups. At the point when the support leg made flat-foot contact with the ground, the players with CAI had more eversion of the hindfoot with respect to the tibia (-28.3° ± 12.1° vs -13.9° ± 14.2°; P = .03), a more varus alignment of the knee (26.0° ± 10.7° vs 13.7° ± 10.5°; P = .03), and a lower arch height index (0.210 ± 0.161 vs 0.233 ± 0.214; P = .046) compared with non-CAI players.

Conclusion:

Significant differences between players with and without CAI were seen in the support leg kinematics at flat-foot contact with the ground during the kicking cycle.

Clinical Relevance:

The biomechanical alignment of the support leg during a side-foot kick in players with CAI may reflect a subconscious attempt to avoid inversion of the foot and further ankle sprains.

Measuring the Reliability of Postural Sway Measurements for a Static Standing Task: The Effect of Age

Background: A force plate is used to determine the ability to balance ability. However, only some medical centers or laboratories are equipped with force plates because they are costly so a low-cost force plate is required for home care or health care institutes. Few studies compare the reliability of postural sway measurements in terms of age. This study proposes a low-cost force plate to select reliable parameters to evaluate postural sway.

Objectives: To determine the intra-rater reliability of a novel force plate and the effect of age difference on the intra-rater test-retest reliability for the center of pressure (COP).

Methods: Forty participants were enrolled for this study: 20 youths and 20 older adults. Participants stood on a custom-made and low-cost force plate with eyes opened and eyes closed to measure COP-related parameters. The within-day test-retest reliability was measured at two sessions on the same day and the between-days reliability was measured on two different days. The COP-related parameters include the average velocity of COP, the average velocity in the antero-posterior and medio-lateral directions, the mean distance of COP and the mean distance in the antero-posterior and medio-lateral directions. An intra-class correlation coefficient test with one-way random model was performed to determine the reliability of different variables within-days and between-days. The results were presented in single measurement of intraclass correlation coefficient (ICC), the standard error of measurements, and the minimal detectable changes of each COP-related parameters.

Results: The novel low-cost force plate demonstrates excellent reliability in terms of the COP velocity related parameters for within- and between-day measurements. The ICC of COP distance related parameters were good to excellent reliability for between-day measurements (range: 0.43–0.84). Older adults demonstrated excellent reliability in terms of the mean distance for antero-posterior and the results were better than those for younger participants for the eyes-opened and eyes-closed conditions. The reliability in terms of the mean distance for medio-lateral was poor to good for older adults (range: 0.38–0.55), and excellent for younger participants.

Conclusion: The novel and low-cost force plate reliably measured balance and age affects the reliability of different COP variables, so the results of this study were pertinent to the selection of COP measures.

Hip Flexibility and Dynamic Balance Ability in Soccer Players with Functional Ankle Instability

The prevention of recurrent ankle sprain and functional ankle instability in soccer players is essential. This study clarified hip joint mobility and dynamic balance ability in soccer players with functional ankle instability. This case–control study included 17 male college soccer players. All participants were assessed using the Cumberland Ankle Instability Tool and were divided into chronic ankle instability (CAI) and non-CAI groups for each of their dominant and nondominant legs. Bilateral passive hip range of motion (ROM) was assessed and the modified Star Excursion Balance Test (mSEBT) was measured for each leg. In the dominant leg, the reach in the posterolateral direction in the CAI group was significantly less than that in the non-CAI group. Hip internal rotation angles in the dominant leg in the CAI group were greater than those in the non-CAI group; however, no significant correlations with the three directions of mSEBT were observed. In the nondominant leg, mSEBT and hip ROMs did not show any significant differences between groups. The dominant leg in soccer players with CAI had poor dynamic balance ability while reaching posterolaterally. However, acquiring hip flexibility may not be necessary to improve the dynamic balance ability. These findings may help develop future research.

Acute Effects of Vibration Foam Rolling Warm-Up on Jump and Flexibility Asymmetry, Agility and Frequency Speed of Kick Test Performance in Taekwondo Athletes

The effect of asymmetry on flexibility and jump in taekwondo athletes and the influence of vibration foam rolling on asymmetry and frequency speed of kick test has not been examined. This study examined the effects of three warm-up protocols on subsequent sports performance in elite male taekwondo athletes. Fifteen elite male taekwondo athletes (20.63 ± 1.18 years) completed three warm-up protocols in a randomized order: general warm-up [GW], GW with vibration foam rolling [GW + VR], and GW with double VR for the weaker leg [GW + double VR]), was delivered before the subsequent tests: flexibility, single-leg countermovement jump (CMJ), 505 agility, hexagon test, and multiple frequency speed of kick tests (FSKTs). Relative to GW, the GW + VR significantly improved the hexagon test (GW + VR = 11.60 ± 1.01 s; GW = 12.80 ± 1.58 s). In addition, the GW + VR and GW + double VR yielded greater kick numbers in FSKT 5 (GW + VR = 21.13 ± 1.96 reps; GW + double VR = 20.93 ± 1.67 reps; GW = 19.27 ± 1.62 reps) and a higher kick decrement index (GW + VR = 5.45 ± 2.57%; GW + double VR = 5.88 ± 3.22%; GW = 9.54 ± 5.00%). However, the GW + VR and GW + double VR did not significantly improve the flexibility and CMJ asymmetry performance. The GW + VR is more beneficial for warming up than the GW is among male collegiate taekwondo athletes.

Effect of Novel Remodeled Bicycle Pedal Training on Balance Performance in Athletes With Functional Ankle Instability

Context

Appropriate training without risk of injury is a critical concern for athletes. Remodeled bicycle pedal training with multi-directional challenges may be effective in improving the balance performance of athletes with functional ankle instability (FAI).

Objective

To evaluate the effects of 6-week modified bicycle pedal training on the balance ability and proprioception of athletes with FAI.

Design

Randomized controlled trial.

Setting

University motion analysis laboratory.

Participants

Fourteen healthy athletes (healthy group) and twenty-six athletes with FAI and an age of 18 to 30 years old. The participants with FAI were randomly distributed to two groups, designated as the training group (AI-T group) and non-training group (AI-NT group), respectively. The athletes in the AI-T group received 6-week remodeled bicycle pedal training, while those in the AI-NT group received no intervention at all.

Intervention

A 6-week training using modified bicycle pedal capable of moving freely during loading cycle vs no intervention.

Main Outcome Measures

The passive ankle joint position sense (JPS) in four angles and the center of pressure (COP) parameters were analyzed during single-leg standing with and without vision, respectively.

Results

A 6-week remodeled pedal training: (1) significantly improved the passive JPS of ankle in all directions (P < 0.05); (2) reduced the excursion of the COP in the medial-lateral (ML) direction (p < 0.05), the velocity of the COP in the ML direction (p < 0.05), and the RMS of the COP in the ML direction (P < 0.05) during single-leg standing both with and without vision.

Conclusion

The remodeled bicycle pedal training improved the passive JPS and reduced the postural sway in single-leg standing both with and without vision. Therefore, remodeled bicycle pedal training can be considered for inclusion in rehabilitation programs for athletes with FAI to restore the proprioception and balance ability.

Does monopedal postural balance differ between the dominant leg and the non-dominant leg? A review

The interlimb postural comparison i.e., between the dominant leg and the non-dominant leg has been studied by numerous authors but their results are contradictory and do not lead to a consensus. Some studies showed no difference of postural balance between the dominant and the non-dominant leg whereas other studies concluded that the dominant and non-dominant leg exhibit different postural balance in healthy subjects and athletes. The aim was to analyse all these studies in order to identify the different factors that could facilitate or prevent the appearance of a postural difference between the dominant and non-dominant leg by means of a narrative review. Environmental and experimental conditions (e.g., difficulty and specificity of postural tasks; physiological state, expertise level and moment of season/period over career of subjects/athletes evaluated and nature of sport/physical activity practiced; techniques and methods used for measuring postural balance) in which postural balance is evaluated and intrinsic/individual factors (e.g., morphology, strength/power muscle, proprioception, hemispheric laterality) could influence the results. Thus, the influence of limb dominance on monopedal postural balance would probably be context-dependent. Mechanistic explanations are proposed to explain how each factor could act on the relationship between limb dominance and postural balance. However many mechanisms have not yet been explained and all the factors have not been identified, which suggests that further exploratory research is needed in order to understand this relationship.

Gender differences in instep soccer kicking biomechanics, investigated through a 3D human motion tracker system

BACKGROUND

This study aims at describing and comparing each other male and female soccer players kicking instep a stationary ball. The different measures we collected by the 3D motion capture system Movit G1 and the High-Speed Camera (240 fps) were considered as dependent variables, whereas the gender was considered as the independent one.

METHODS

Twenty soccer well trained non-professional players: 10 men (age: 25.3±6.5 yrs; height 1.80±0.07 m; body mass 76.9±13.2 kg) and 10 women (age: 19±3.34 yrs; height 1.64±0.07 m; body mass 58.2±7.2 kg) volunteered to participate in the study.

RESULTS

Gender differences were found, with a statistical significance (P<0.05) or interesting magnitude (Cohen d>0.5). The most relevant ones were the differences in hip extension of the kicking leg when the foot of the supporting one touches the ground, just before the impact on the ball (independent sample t-Test; P=0.03; Cohen d=1.64) and the speed of the ball, reached immediately after kicking (P<0.001;d=1.23).

CONCLUSIONS

These results, together with the greater pelvic acceleration shown by men compared to women, highlight the need to develop a gender-differentiated training model, in order to customize the kicking technique in women and to reduce the likelihood, currently higher than for men, of kicking related injuries.

Preseason Dynamic Balance Performance in Healthy Elite Male Soccer Players

Lower limb musculoskeletal injuries in sports are linked with balance abnormalities and altered postural control. Dynamic balance screening should be performed in order to identify athletes at risk. The purpose of the study was to evaluate the preseason dynamic balance performance and side-to-side asymmetry of healthy elite male soccer players, using modified Star Excursion Balance Test (mSEBT). Seventy-three elite soccer players (23.8 ± 5.4 years) were evaluated using the mSEBT. Normalized reach distances, side-to-side asymmetries, and composite scores were determined. The composite scores were 93.33% ± 8.99% for dominant leg and 93.36% ± 9.23% for nondominant leg. No significant differences were found between dominant and nondominant limb in any direction. The mSEBT is an easy-to-use tool to measure the dynamic balance performance in elite athletes. It can be applied successfully during preseason physical examinations. Future studies are needed to establish predictive cutoff points in order to increase mSEBT use in screening soccer players for dynamic balance abnormalities and identify those at risk for noncontact lower limb injuries.

Single-Leg Balance Performance in Sub-Elite Young Soccer Players and Swimmers as a Function of Age and Sports Experience

The present study investigated if accumulated, advanced, regular soccer practice (balance-demanding exercise) compared to regular swim practice (non-balance–demanding exercise) induces a more pronounced functional specialization in postural control. Therefore, single-leg balance performance in sub-elite young soccer players (under 13 [U13]: n = 16; U15: n = 18; U19: n = 15), and sub-elite young swimmers (U13: n = 7; U15: n = 4; U19: n = 5) was tested in different balance task conditions (i.e., static and dynamic balance on firm and foam surface). All athletes practiced 3–10 times per week. Single-leg balance of the dominant and non-dominant leg was measured using a force plate. The standard deviation of the center of pressure displacements in anterior-posterior and medio-lateral directions were used as dependent variables. Irrespective of age groups and type of sport, the results failed to indicate significant leg differences in single-leg balance performance. The soccer players showed significant better single-leg balance performance in anterior-posterior direction in the dynamic balance test on the firm and foam surface compared to the swimmers. Functional specialization was accompanied by the type of sport but not by accumulated practice.

Applicability of the Movement Assessment Battery for Children-Second Edition (MABC-2) for Japanese Children Aged 3-6 Years: A Preliminary Investigation Emphasizing Internal Consistency and Factorial Validity

This study investigated the applicability of the Movement Assessment Battery for Children - Second Edition (MABC-2) for 3- to 6-year-old Japanese children, particularly addressing its internal consistency and factorial validity. The MABC-2 test set for 3- to 6-year-old children was administered to 252 children. Differences between Japanese children and those of the original normative sample (i.e. United Kingdom children) were investigated along with sex differences. The Japanese children aged 3-6 years were found to have higher Manual Dexterity and Balance component scores than children of the normative sample. Girls scored higher than boys on the Balance component. Results of several analyses showed good internal consistency of the MABC-2. Confirmatory factor analysis revealed that a theoretical three-component model of the MABC-2 was not fitted to Japanese children aged 3-6 years. Instead, a new three-component model was postulated and discussed. The new three-component model of the MABC-2, with Manual Dexterity, Static Balance and Ball Skills, and Dynamic Balance, has high factorial validity in Japanese children aged 3-6 years.

Evidence of balance training-induced improvement in soccer-specific skills in U11 soccer players

The present study aimed to determine the role of balance training improving technical soccer skills in young players. Two U11 soccer teams were randomly assigned one to either balance training (BT; n = 22) or control group (Ctrl; n = 21). At the end of their habitual soccer training (identical in BT and Ctrl), BT underwent additional balance training for 12 weeks (3 sessions/week, 20 minutes per session), while Ctrl had a 20-minute scrimmage. Before and after the intervention, BT and Ctrl underwent two soccer-specific tests (Loughborough Soccer Passing, LSPT, and Shooting, LSST, Tests), and bipedal and unipedal balance evaluations. After intervention, both groups decreased the trials time and improved passing accuracy, with larger improvements in BT than Ctrl (LSPT penalty time [CI_95% ]: -2.20 seconds [-2.72/-1.68]; ES [CI_95% ]: -2.54 seconds [-3.34/-1.74]). Both groups improved balance ability, with BT showing larger increments in bipedal tests than Ctrl (static balance: -29 mm [-42/-16]; ES: -1.39 [-2.05/-0.72]; limit of stability: 4% [3/5]; ES 3.93 [2.90/4.95]; unipedal quasi-dynamic balance: 0.07 a.u. [0.03/0.11]; ES: 1.04 [0.40/1.67] and active range of motion: -5% [-8/-2]; ES -0.89 [-1.51/-0.26]). Low-to-moderate correlations between the players' technical level and unipedal balance ability were retrieved, particularly in the non-dominant limb (R from 0.30 to 0.48). Balance training improved some technical soccer skills more than habitual soccer training alone, suggesting that young soccer players may benefit from additional balance training added to their traditional training.

Current Soccer Footwear, Its Role in Injuries and Potential for Improvement

Soccer is the most popular sport in the world and generates great financial revenue. It is also a sport whose practice has evolved considerably in terms of intensity and commitment, and in which the intrinsic risk of injury (not directly related to an interaction with the environment) is particularly high. In this context, the cleated shoe as a major component of soccer equipment may play a key role in the overexposure to injury. Soccer shoe evolution is all the more challenging, because design and mechanical structure differ in many points compared to other modern shoes developed for sports such as running, tennis and basketball. This critical review aims to elucidate the characteristics of modern soccer footwear and their possible link to soccer-specific injuries, focusing on the following areas: (1) ergonomics, comfort and proprioception; (2) shoe mechanical characteristics; (3) field surfaces and shoe design.

RAD, Rosa LM, Mesquita TRD, Oliveira PRD, Burigo RL, Amorim CF. POSTURAL CONTROL ANALYSIS DURING A STANDARDIZED KICK TASK IN SOCCER ATHLETES

ABSTRACT Introduction: Postural control is a determining factor for functional performance and motor skills during sports activities. Objective: The objective of this study was to investigate postural control during the controlled soccer ball kicking task through a biomechanical analysis system. Methods: The sample consisted of 11 professional male athletes recruited using convenience sampling, with a mean age of 22 years. The athletes performed twenty-five precision kicks at a target, with the ball in vertical motion released by means of a hand-held device synchronized with the computed biomechanical measurements. Marking of the lower limb segments involved in the kick and the ball were analyzed by accelerometry, while postural control measures were quantified by a force platform in three axes of movement. The support leg was investigated in single leg stance during all tests on the force platform. The main variables of postural control calculated by stabilographic analysis and computed during the 25 kicks were: center of pressure (COP) displacement area, velocity and frequency of COP oscillation in the anteroposterior and mediolateral directions. The mean was used for final analysis to determine the differences in the three phases: pre-kick, kick, and post-kick. Results: The results revealed significant differences (p <0.01) between the three phases, with the kick phase presenting higher values of postural COP oscillations than the other phases. The COP area and oscillation velocity were the variables with greatest sensitivity to changes in the kick phase, obtaining an effect size of d = 14 and d = 12, respectively. In clinical terms, the increase in COP values reached 557% between the pre-kick and kick phases; this difference was reduced to 241% when compared to post-kick (i.e., difference between kick and post-kick was 316%). Conclusion . These results have important implications for the perception of postural control responses during soccer ball kicks and consequently, for injury prevention when motor and sensory deficits are diagnosed in soccer players. Level of Evidence III; Study of nonconsecutive patients; without consistently applied reference ‘‘gold’’ standard.

Influence of dual-task constraints on the interaction between posture and movement during a lower limb pointing task

One of the challenges regarding human motor control is making the movement fluid and at a limited cognitive cost. The coordination between posture and movement is a necessary requirement to perform daily life tasks. The present experiment investigated this interaction in 20 adult men, aged 18-30 years. The cognitive costs associated to postural and movement control when kicking towards a target was estimated using a dual-task paradigm (secondary auditory task). Results showed that addition of the attentional demanding cognitive task yielded a decreased kicking accuracy and an increased timing to perform the movement, mainly during the backswing motion. In addition, significant differences between conditions were found for COP and COM displacement (increased amplitude, mean speed) on the anteroposterior axis. However, no significant differences between conditions were found on the mediolateral axis. Finally, EMG analysis showed that dual-task condition modified the way anticipatory postural adjustments (APAs) were generated. More specifically, we observed an increase of the peroneus longus activity, whereas the temporal EMG showed a decrease of its latency with respect to movement onset. These results suggested a functional adaptation resulting in an invariance of overall APAs, emphasizing that cognitive, postural, and motor processes worked dependently.

The Role of Postural Support in Young Adults' Control of Stationary Kicking

PURPOSE

The requirement for postural stability during the performance of motor skills has been clearly demonstrated in infants, but the necessity for such a postural substrate is not well documented in adults. The present study investigated the role of postural stability during a ballistic ball-kicking task in adults by providing varying degrees of external postural support.

METHOD

In the 1st experiment, 30 participants performed 20 maximal-velocity kicks under each of 3 conditions: grasping a rigid stable handle, light fingertip touch, and grasping a suspended elastic tube. A 2nd experiment with 16 participants varied the position of the stable handle to examine if the handle position in Experiment 1 might simply act as a fulcrum to enhance torque generation.

RESULTS

In Experiment 1, ball velocity was significantly higher in the stable-grasp condition in both men and women with the men showing greater improvement relative to the other conditions. Experiment 2 showed that the position of the stable handle did not significantly affect kicking velocity, indicating that the handle was not simply acting as a fulcrum during the kick.

CONCLUSION

Together, the findings suggest that postural stability may be a rate limiter in the performance of dynamic motor tasks in adults.

Effect of a specialized injury prevention program on static balance, dynamic balance and kicking accuracy of young soccer players

AIM

To study the effect of balance intervention program using the “FIFA 11+” program on static and dynamic balance and kicking accuracy of young soccer players.

METHODS

Twenty young soccer players were allocated to experimental (n = 10) or control (n = 10) groups. The experimental group performed the “FIFA 11+” program three times a week for six weeks. The control group performed their normal warm-up routine. The primary outcomes were measured pre and post intervention, and assessed kicking accuracy, static balance and dynamic balance.

RESULTS

No differences were found in kicking accuracy following intervention, for both groups, however, static balance improved significantly among the experimental group with significant interaction with the control group, and with high effect size. In addition, the dynamic balance of the left leg of the experimental group, with medium effect size for interaction between groups.

CONCLUSION

The large effect size of balance improvement that was observed following six weeks of intervention sessions, implies that soccer trainers and coaches should consider the inclusion of “FIFA 11+” as components of programs aimed at improving balance ability/control in young soccer players, as improvement in balance abilities may prevent injuries.

The acute effects of graded physiological strain on soccer kicking performance: a randomized, controlled cross-over study

PURPOSE

The aim of the present study was to examine the acute effects of graded physiological strain on soccer kicking performance.

METHODS

Twenty-eight semi-professional soccer players completed both experimental and control procedure. The experimental protocol incorporated repeated shooting trials combined with a progressive discontinuous maximal shuttle-run intervention. The initial running velocity was 8 km/h and increasing for 1 km/h every 3 min until exhaustion. The control protocol comprised only eight subsequent shooting trials. The soccer-specific kicking accuracy (KA; average distance from the ball-entry point to the goal center), kicking velocity (KV), and kicking quality (KQ; kicking accuracy divided by the time elapsed from hitting the ball to the point of entry) were evaluated via reproducible and valid test over five individually determined exercise intensity zones.

RESULTS

Compared with baseline or exercise at intensities below the second lactate threshold (LT2), physiological exertion above the LT2 (blood lactate > 4 mmol/L) resulted in meaningful decrease in KA (11-13%; p < 0.05), KV (3-4%; p < 0.05), and overall KQ (13-15%; p < 0.01). The light and moderate-intensity exercise below the LT2 had no significant effect on soccer kicking performance.

CONCLUSIONS

The results suggest that high-intensity physiological exertion above the player's LT2 impairs soccer kicking performance. In contrast, light to moderate physiological stress appears to be neither harmful nor beneficial for kicking performance.

Fundamental Movement Skills Are More than Run, Throw and Catch: The Role of Stability Skills

INTRODUCTION

In motor development literature fundamental movement skills are divided into three constructs: locomotive, object control and stability skills. Most fundamental movement skills research has focused on children's competency in locomotor and object control skills. The first aim of this study was to validate a test battery to assess the construct of stability skills, in children aged 6 to 10 (M age = 8.2, SD = 1.2). Secondly we assessed how the stability skills construct fitted into a model of fundamental movement skill.

METHOD

The Delphi method was used to select the stability skill battery. Confirmatory factor analysis (CFA) was used to assess if the skills loaded onto the same construct and a new model of FMS was developed using structural equation modelling.

RESULTS

Three postural control tasks were selected (the log roll, rock and back support) because they had good face and content validity. These skills also demonstrated good predictive validity with gymnasts scoring significantly better than children without gymnastic training and children from a high SES school performing better than those from a mid and low SES schools and the mid SES children scored better than the low SES children (all p < .05). Inter rater reliability tests were excellent for all three skills (ICC = 0.81, 0.87, 0.87) as was test re-test reliability (ICC 0.87-0.95). CFA provided good construct validity, and structural equation modelling revealed stability skills to be an independent factor in an overall FMS model which included locomotor (r = .88), object control (r = .76) and stability skills (r = .81).

DISCUSSION

This study provides a rationale for the inclusion of stability skills in FMS assessment. The stability skills could be used alongside other FMS assessment tools to provide a holistic assessment of children's fundamental movement skills.

Does movement proficiency impact on exergaming performance?

There is growing interest in the use of consumer level exergames in movement skill acquisition. The purpose of this study was to investigate the relationship between movement proficiency and performance in virtual exergaming. Twenty seven children, aged 10-15years participated in an experiment completing the Movement Assessment Battery for Children 2 (MABC-2) and a series of XBOX360 Kinect Sports exergaming tasks. Significant correlations were observed between MABC-2 aiming and catching percentile and exergame javelin and target kick, where the more proficient movers tended to perform better in the exergame. Statistically significant correlations were observed between MABC-2 balance percentile and exergaming sprint and target kick performance. In this study children who scored better in real life gross motor movement tasks performed better in most related exergaming activities. This suggests current exergaming technology has advanced to a point where body movement unencumbered by a physical or remote game device tether can extract movements resembling real life tasks, translate them into game play and reward proficient movers with higher in-game performance. It is possible that benefit gained in an exergaming environment by more proficient movers was a result of either their more proficient movement, or a greater ability to adapt to the exergame.