Analysis of static balance performance and dynamic postural priority according to playing position in elite soccer players

Comparison of dynamic and static balance among professional male soccer players by position

PURPOSE

Balance is an important performance aspect of all athletes. The aim of this study was to compare static and dynamic balance in soccer players in different positions.

METHODS

Forty youth and young adult professional soccer players were divided into four groups according to their playing positions: goalkeepers (GK), defenders (DF), midfielders (MF) and forwards (FW) (10 per position). Static and dynamic balance assessed on the dominant and non-dominant legs were measured using a force platform for 30s (static one-leg stand), and "Y Balance Test" (dynamic balance).

RESULTS

GK exhibited greater ML static balance (less ML sway) compared with other players (p < 0.02-0.001). Moreover, results demonstrated better GK dynamic balance compared to DF and FW (p < 0.04-0.006). MF showed better dynamic balance than DF and FW (p < 0.019-0.007) and lower dynamic balance scores were found among DF and FW (p < 0.05).

CONCLUSION

In conclusion, these results affirm position-specific balance performance with greater static and dynamic balance of GK and dynamic balance with MF. It is suggested that evaluation of balance and postural control performance should be considered a relevant part of the position-specific functional evaluation of soccer players.

Sport dependent effects on the sensory control of balance during upright posture: a comparison between professional horseback riders, judokas and non-athletes

Introduction

Compared to judokas (JU) and non-athletes (NA), horseback riders (HR) may develop specific changes in their sensory control of balance.

Methods

Thirty-four international-level JU, twenty-seven international-level HR and twenty-one NA participated. Participants stood upright on a plateform (static condition) or on a seesaw device with an instability along the mediolateral (ML) or the anteroposterior (AP) direction (dynamic conditions). These conditions were carried out with eyes opened (EO) or closed (EC), and with (wF) or without a foam (nF). Experimental variables included conventional (linear), non-linear center-of-pressure (COP) parameters, Romberg Quotient (RQ) and Plantar Quotient (PQ).

Results

Group effects. COP Surface (COPS) and standard deviation of COP along AP (SDY) were lower in HR than in JU in Static. SD Y was lower in HR than in JU in Dynamic AP. COP velocity (COPV) was lower in both HR and JU than in NA in Static and Dynamic. Sample entropy along AP and ML (SampEnY and SampEnX) were higher in HR than in JU in Static. SampEnY was higher in HR than in JU in Dynamic ML. Sensory effects. In EC, COPV was lower in JU than in NA in Dynamic AP, and lower in JU than in both HR and NA in Dynamic ML. In EO, COPV was lower in both JU and HR than in NA in Dynamic ML. RQ applied to COPS was lower in JU than in both HR and NA in Dynamic AP, and lower in JU than in HR in Dynamic ML. RQ applied to COPV was lower in JU than in both HR and NA in Static and Dynamic. PQ applied to COPS was higher in JU than in both HR and NA in Dynamic ML.

Conclusion

Results showed that the effects of sport expertise on postural control could only be revealed with specific COP variables and were directionally oriented and sport-dependant. HR seem to rely more on vision than JU, thus revealing that the contribution of the sensory inputs to balance control is also sport-dependent. Results open up new knowledge on the specificity of sport practice on multisensory balance information during upright posture.

The optimal method for improving postural balance in healthy young and older people: specific training for postural tasks encountered in personal physical practice

It is well known that regular exercise or physical activity (training) improves postural balance in healthy young and older subjects, but the optimal exercise or physical activity (i.e., likely to induce the greatest postural improvements) and the context in which it is carried out remain to be explored and determined for each population. The most beneficial adaptations would depend, in particular, on gestural conditions (body position, movement and gesture practiced) and material conditions (nature of the ground surface, sports equipment used, type of environment - stable or changing). In fact, the global postural adaptations induced by training do not result from the transfer between different trained and untrained postural tasks, but are the sum of the adaptations related to each trained postural task in healthy young and older subjects. Based on current knowledge, optimal training programs should include the full range of postural tasks encountered in personal physical practice for each population. To date, the method of implementing progressive postural balance tasks with different degrees of difficulty and instability has been used as the effective method to improve postural balance, but it should not be considered as the reference method. Instead, it should be considered as a complementary method to the one based on specific postural tasks. An intervention strategy is proposed for young and older adults consisting of three different steps (general, oriented and specific/ecologic training). However, some parameters still need to be explored and possibly reconsidered in future studies to improve postural balance in an optimal way.

Sport-specific training induced adaptations in postural control and their relationship with athletic performance

Effects of various exercise programs on postural balance control in athletes and their underlying physiological mechanisms have been extensively investigated. However, little is known regarding how challenging sport-specific conditions contribute to the improvement of body balance and to what extent these changes may be explained by sensorimotor and/or neuromuscular function adaptations. Analysis of the literature could provide useful information on the interpretation of changes in postural sway variables in response to long-term sport-specific training and their association with performance measures. Therefore, the aim of this scoping review was (1) to analyze the literature investigating postural control adaptations induced by sport-specific training and their relationship with measures of athletic performance, and (2) to identify gaps in the existing research and to propose suggestions for future studies. A literature search conducted with Scopus, Web of Science, MEDLINE and Cochrane Library was completed by Elsevier, SpringerLink and Google Scholar with no date restrictions. Overall, 126 articles were eligible for inclusion. However, the association between variables of postural balance control and measures of sport-specific performance was investigated in only 14 of the articles. A relationship between static and/or dynamic balance and criterion measures of athletic performance was revealed in shooting, archery, golf, baseball, ice-hockey, tennis, and snowboarding. This may be ascribed to improved ability of athletes to perform postural adjustments in highly balanced task demands. However, the extent to which sport-specific exercises contribute to their superior postural stability is unknown. Although there is a good deal of evidence supporting neurophysiological adaptations in postural balance control induced by body conditioning exercises, little effort has been made to explain balance adaptations induced by sport-specific exercises and their effects on athletic performance. While an enhancement in athletic performance is often attributed to an improvement of neuromuscular functions induced by sport-specific balance exercises, it can be equally well ascribed to their improvement by general body conditioning exercises. Therefore, the relevant experiments have yet to be conducted to investigate the relative contributions of each of these exercises to improving athletic performance.

Muscle Contractile Properties Measured by the Tensiomyography (TMG) Method in Top-Level Football Players of Different Playing Positions: The Case of Serbian Super League

The aim of this study is to investigate the differences in muscle contractile properties measured by the TMG method between top-level football players of different playing positions. The sample consisted of 57 football players from the Serbian Super League, divided into three groups: defenders-DF, midfielders-MF, and forwards-FW. Muscles included in the study were the Rectus Femoris (RF), Vastus Medialis (VM), Vastus Lateralis (VL), Biceps Femoris (BF), and Semitendinosus (ST) of the right (R) and left (L) leg. The TMG parameters used in this study were contraction time (Tc), delay time (Td), relaxation time (Tr), maximal displacement (Dm), and sustain time (Ts). The ANOVA results showed that differences in TMG parameters between top-level football players of different playing positions are small and exist only in the Tr of RF (F = 4.658, p = 0.014), BF (F = 4.433, p = 0.016), and ST muscle (F = 3.808, p = 0.028), and the Tc (F = 3.214, p = 0.048) and Td (F = 3.705, p = 0.031) of the VM muscle. All differences were detected between DF and FW players, and all differences were in the left (non-dominant) leg. The results obtained in this study indicate that the training and selection process in football, from the aspect of functional and mechanical muscle properties, should be similar for all players, regardless of playing position. It has been shown that TMG has relatively low sensitive strength for detecting differences between football players of different playing positions.

Physical Development Differences between Professional Soccer Players from Different Competitive Levels

In soccer, physical development is crucial for developing optimal performance. This study aimed to assess and compare the physical development of elite and non-elite professional soccer players. Seventy-eight male professional football players divided into four competitive levels participated in this study: the elite group (EG), the non-elite group A (NEG-A), the non-elite group B (NEG-B), and the under 23 group (U23). Body composition, static strength, lower-body explosive strength, flexibility, and balance were assessed. No significant statistical differences between elite and non-elite players were seen in body composition parameters. However, the EG performed better in static strength, lower-body explosive strength, flexibility, and balance, even after adjusting for the effects of chronological age. The analysis showed that the competitive level (group) explained 25% to 29% of the variance observed in the lower-body explosive strength tasks. Sports staff and coaches in different age categories or competitive levels should include specific lower-body explosive strength content during soccer training to promote players’ long-term development towards the elite level.

Warm-Up Improves Balance Control Differently in the Dominant and Non-Dominant Leg in Young Sportsmen According to Their Experience in Asymmetric or Symmetric Sports

The aim of this study was to investigate the acute effects of a warm-up on balance control and inter-limb balance asymmetries by analyzing the influence of the nature of the sport practiced by participants. Twelve sportspeople were recruited. They had to stand on a force plate for 30 s in a one-leg stance on their dominant (used to perform skilled movements) and non-dominant leg (used to support the body) before and 2, 5, 10, 15 and 20 min after a 10 min warm-up exercise performed at moderate intensity on a cycle ergometer. The center of foot pressure displacements was recorded. Statistical analysis was performed by considering one group of all participants and with two subgroups according to the symmetrical or asymmetrical nature of the sport they practiced. The warm-up exercise improved acute balance control only on the dominant leg after a 20 min rest without significantly reducing inter-limb balance asymmetries. This effect was more characteristic of participants with experience in asymmetric sports. These results confirm previous findings of the greater sensitivity of the dominant leg to the physiological state and reveal that between-leg differences in balance control appear mainly in subjects with experience in asymmetric sports in a specific physiological condition (post-warm-up state).

The soccer goalkeeper profile: bibliographic review

OBJECTIVE

The main aim of this article was to review the existing scientific literature on the soccer goalkeeper.

METHOD

This article has reviewed the scientific literature related to the soccer goalkeeper as long as they offered specific information about this position on the field, including a total of 56 scientific articles.

RESULTS

The knowledge already recollected by authors to be able to apply it on training has been divided in the following chapters: anthropometric profile, conditional and performance profile (sprint, jump, agility, strength, aerobic capacity, mobility, and specific game technique), external load profile, and injury pathological profile.

CONCLUSION

The most noteworthy conclusions obtained are: 1) the higher the level of the team, the higher and heavier the goalkeepers; 2) in early ages (9-13 years) the training of goalkeepers is not well posed, since compared to the players are worse both in physical capacities and technique; 3) the aerobic capacity at long distances does not influence the performance of the goalkeeper; 4) the sprint, the jump, the agility, and the mobility are factors that determine the performance of the goalkeeper; 5) the goalkeepers are less likely to be injured than the field players, but there are certain typical injuries in the position that must be protected by a proper way of strengthening and technique.

The Role of Neuromuscular Control of Postural and Core Stability in Functional Movement and Athlete Performance

Balance and core stabilization exercises have often been associated with improved athlete performance and/or decreased incidence of injuries. While these exercises seem to be efficient in the prevention of injuries, there is insufficient evidence regarding their role in sport-specific performance and related functional movements. The aim of this scoping review is (1) to map the literature that investigates whether currently available variables of postural and core stability are functionally related to athlete performance in sports with high demands on body balance and spinal posture and (2) to identify gaps in the literature and suggest further research on this topic. The literature search conducted on MEDLINE, Scopus, Web of Science, PubMed, and Cochrane Library databases was completed by Google Scholar, SpringerLink, and Elsevier. Altogether 21 articles met the inclusion criteria. Findings revealed that postural stability plays an important role in performance in archery, biathlon, gymnastics, shooting, and team sports (e.g., basketball, hockey, soccer, tennis). Also core stability and strength represent an integral part of athlete performance in sports based on lifting tasks and trunk rotations. Variables of these abilities are associated with performance-related skills in cricket, cycling, running, and team sports (e.g., baseball, football, hockey, netball, soccer, tennis). Better neuromuscular control of postural and core stability contribute to more efficient functional movements specific to particular sports. Training programs incorporating general and sport-specific exercises that involve the use of postural and core muscles showed an improvement of body balance, back muscle strength, and endurance. However, there is controversy about whether the improvement in these abilities is translated into athletic performance. There is still a lack of research investigating the relationship of body balance and stability of the core with sport-specific performance. In particular, corresponding variables should be better specified in relation to functional movements in sports with high demands on postural and core stability. Identifying the relationship of passive, active, and neural mechanisms underlying balance control and spinal posture with athlete performance would provide a basis for a multifaced approach in designing training and testing tools addressing postural and core stability in athletes under sport-specific conditions.

Static balance performance differs depending on the test, age and specific role played in acrobatic gymnastics

BACKGROUND

Static balance performance appears to detect differences between roles played in team sports. Static balance can also be influenced by the subject's height and age, and the type of test used.

RESEARCH QUESTION

Could the static balance profile show differences among the role played depending on the specific test evaluated and the gymnasts' age?

METHODS

A cross-sectional design was applied. 46 acrobatic gymnasts (37 females and 9 males) were divided in four groups according to role (base or top gymnast) and stage of adolescence (early adolescent or mid-adolescent) during two different static tests: (1) unipedal with open and closed eyes (generic), and (2) headstand (specific). To test the effect of the role and the age group, a two-way analysis of variance (ANOVA) between groups was performed. Centre of pressure (COP) measurements were obtained and normalised relative to participants height, including length travelled on the anteroposterior and mediolateral axis (AP_CoP and ML_CoP) and the mean speed (SP_CoP).

RESULTS

Base gymnasts obtained lower values in the CoP excursion than Top gymnasts but only in unipedal tests for all the variables analysed (5.536 ≥ F_1,42 ≤ 10.589, 0.002 ≥ p ≤ 0.023), except for the AP_CoP in unipedal-closed. Mid-adolescent gymnasts obtained lower values in the CoP excursion regardless of the task than early adolescent (5.324 ≥ F_1,42 ≤ 14.805, 0.000 ≥ p ≤ 0.026).

SIGNIFICANCE

It has been observed a clear effect of age on the static balance manifested in acrobatic gymnastics, regardless of the subject's height, the role played, and the test performed. The effect of the role played in this team sport has been different depending on the type of test performed.

Differences in physical fitness after an 8-week preseason training among elite football players aged 17-19 years

There may be an optimal period of time to maximize the improvement of physical fitness during adolescence. The aim of this study was to examine the magnitude of changes in physical fitness after 8 weeks of preseason training according to chronological ages after the age at peak high velocity. Thirty male young football players from an elite football team (U-16, n=10; U-17, n=10; U-18, n=10) participated in the study. The players completed an 8-week general preseason football training and participated in the pre- and posttests to measure physical fitness. The 8-week preseason training improved the power of all young players (P<0.05). The 20-m sprint performance was improved by training in U-16 and U-18 (P<0.05), but no changes were found in the U-17 group (P>0.05). Significant differences were found in the arrowhead left in U-16 and U-18 (P<0.05) after training; however, no difference was observed in U-17 (P>0.05). Coordination was enhanced further in U-16 and U-17 (P<0.05) compared with that in U-18 (P>0.05). The performance of repeated sprints and Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) were similar between pre- and posttraining in all age groups (P>0.05). Collectively, the results emphasized the importance of systematic and scientific training methods to improve the fitness levels of young football players in the preseason training period. Moreover, training to improve coordination in young football players is effective at younger ages.