Issues

Journal & Issues

Volume 84 (2022): Issue 1 (October 2022)

Volume 83 (2022): Issue 1 (August 2022)

Volume 82 (2022): Issue 1 (April 2022)

Volume 81 (2022): Issue 1 (January 2022)

Volume 80 (2021): Issue 1 (October 2021)

Volume 79 (2021): Issue 1 (July 2021)

Volume 78 (2021): Issue 1 (March 2021)

Volume 77 (2021): Issue 1 (January 2021)

Volume 76 (2021): Issue 1 (January 2021)

Volume 75 (2020): Issue 1 (October 2020)

Volume 74 (2020): Issue 1 (August 2020)

Volume 73 (2020): Issue 1 (July 2020)

Volume 72 (2020): Issue 1 (March 2020)

Volume 71 (2020): Issue 1 (January 2020)

Volume 70 (2019): Issue 1 (November 2019)

Volume 69 (2019): Issue 1 (October 2019)

Volume 68 (2019): Issue 1 (August 2019)

Volume 67 (2019): Issue 1 (June 2019)

Volume 66 (2019): Issue 1 (March 2019)

Volume 65 (2018): Issue 1 (December 2018)

Volume 64 (2018): Issue 1 (September 2018)

Volume 63 (2018): Issue 1 (August 2018)

Volume 62 (2018): Issue 1 (June 2018)

Volume 61 (2018): Issue 1 (March 2018)

Volume 60 (2017): Issue 1 (December 2017)

Volume 59 (2017): Issue 1 (October 2017)

Volume 58 (2017): Issue 1 (September 2017)

Volume 57 (2017): Issue 1 (June 2017)

Volume 56 (2017): Issue 1 (February 2017)

Volume 55 (2017): Issue 1 (January 2017)

Volume 54 (2016): Issue 1 (December 2016)

Volume 53 (2016): Issue 1 (December 2016)

Volume 52 (2016): Issue 1 (September 2016)

Volume 51 (2016): Issue 1 (June 2016)

Volume 50 (2016): Issue 1 (April 2016)

Volume 49 (2015): Issue 1 (December 2015)

Volume 48 (2015): Issue 1 (December 2015)

Volume 47 (2015): Issue 1 (September 2015)

Volume 46 (2015): Issue 1 (June 2015)

Volume 45 (2015): Issue 1 (March 2015)

Volume 44 (2014): Issue 1 (December 2014)

Volume 43 (2014): Issue 1 (November 2014)

Volume 42 (2014): Issue 1 (September 2014)

Volume 41 (2014): Issue 1 (June 2014)

Volume 40 (2014): Issue 1 (March 2014)

Volume 39 (2013): Issue 1 (December 2013)

Volume 38 (2013): Issue 2013 (September 2013)

Volume 37 (2013): Issue 1 (June 2013)

Volume 36 (2013): Issue 1 (March 2013)

Volume 35 (2012): Issue 1 (December 2012)

Volume 34 (2012): Issue 1 (October 2012)

Volume 33 (2012): Issue 2012 (June 2012)

Volume 32 (2012): Issue 2012 (May 2012)
Aquatic Sports and Activities

Volume 31 (2012): Issue 2012 (March 2012)

Volume 30 (2011): Issue 2011 (December 2011)

Volume 29A (2011): Issue Special-Issue (September 2011)
Presentation of the 1st International Symposium on Strength & Conditioning (ISSC 2011)

Volume 29 (2011): Issue 2011 (September 2011)

Volume 28 (2011): Issue 2011 (June 2011)

Volume 27 (2011): Issue 2011 (March 2011)

Volume 26 (2010): Issue 2010 (December 2010)

Volume 25 (2010): Issue 2010 (September 2010)

Volume 24 (2010): Issue 2010 (June 2010)

Volume 23 (2010): Issue 2010 (March 2010)

Volume 22 (2009): Issue 2009 (December 2009)

Volume 21 (2009): Issue 2009 (June 2009)

Volume 20 (2008): Issue 2008 (December 2008)

Volume 19 (2008): Issue 2008 (June 2008)

Journal Details
Format
Journal
eISSN
1899-7562
ISSN
1640-5544
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

Volume 36 (2013): Issue 1 (March 2013)

Journal Details
Format
Journal
eISSN
1899-7562
ISSN
1640-5544
First Published
13 Jan 2009
Publication timeframe
5 times per year
Languages
English

Search

18 Articles
Open Access

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

Published Online: 13 Apr 2013
Page range: 5 - 160

Abstract

Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., 'to hold' vs. 'to pull') can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely, the effects of handedness could be relatively week showing only slight lagging of GF in the non-dominant, but not in the dominant hand. The presented findings reveal important aspects of hand function as seen through GF-LF coordination. Specifically, the use of specific hand areas for grasping, calculation of particular safety margins, the role of LF frequency (but not of LF range) and the effects of given instructions should be all taken into account when conducting future studies of manipulation tasks, standardizing their procedures and designing routine clinical tests of hand function.

Keywords

  • grip force
  • load force
  • coupling
  • scaling
  • modulation
Open Access

Short-Term High Intensity Plyometric Training Program Improves Strength, Power and Agility in Male Soccer Players

Published Online: 13 Apr 2013
Page range: 17 - 26

Abstract

The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.

Keywords

  • knee extensors
  • depth jump
  • dynamometer
  • unilateral
  • plyometrics
Open Access

Effect of Yellow-Tinted Lenses on Visual Attributes Related to Sports Activities

Published Online: 13 Apr 2013
Page range: 27 - 36

Abstract

The purpose of this study was to clarify the effect of colored lenses on visual attributes related to sports activities. The subjects were 24 students (11 females, 13 males; average age 21.0 ±1.2 years) attending a sports university. Lenses of 5 colors were used: colorless, light yellow, dark yellow, light gray, and dark gray. For each lens, measurements were performed in a fixed order: contrast sensitivity, dynamic visual acuity, depth perception, hand-eye coordination and visual acuity and low-contrast visual acuity. The conditions for the measurements of visual acuity and low-contrast visual acuity were in the order of Evening, Evening+Glare, Day, and Day+Glare. There were no significant differences among lenses in dynamic visual acuity and depth perception. For hand-eye coordination, time was significantly shorter with colorless than dark gray lenses. Contrast sensitivity was significantly higher with colorless, light yellow, and light gray lenses than with dark yellow and dark gray lenses. The low-contrast visual acuity test in the Day+Glare condition showed no significant difference among the lenses. In the Evening condition, lowcontrast visual acuity was significantly higher with colorless and light yellow lenses than with dark gray lenses, and in the Evening+Glare condition, low-contrast visual acuity was significantly higher with colorless lenses than with the other colors except light yellow. Under early evening conditions and during sports activities, light yellow lenses do not appear to have an adverse effect on visual attributes.

Keywords

  • sports
  • low-contrast visual acuity
  • contrast sensitivity
  • dynamic visual acuity
Open Access

Asymmetry of Spinal Segments Mobility in Canoeists and its Relationship with Racing Speed

Published Online: 13 Apr 2013
Page range: 37 - 43

Abstract

The aim of this study was to determine the extent of asymmetry of spinal segment mobility in canoeists. Moreover, the relationship between this parameter and racing speed was analyzed. The study included 18 canoeists with a mean age of 16.4 years. Mobility of cervical, thoracic and lumbar spine, in sagittal, coronal and transverse planes, was measured with the aid of a tensometric electrogoniometer. The racing speed was based on results achieved during the qualifying competition for the Polish national team. Spinal mobility was measured within two days after the competition. Significant associations were observed between average racing speed and the asymmetry coefficients of the cervical (r=-0.52; p=0.03) and lumbar spinal flexure in the coronal plane (r=0.57; p=0.01). The extent of the asymmetry of the cervical spine flexure in the coronal plane should possibly be reduced, because such asymmetry exerts a negative effect on racing speed. In contrast, canoeist’s training should be oriented towards increasing the asymmetry of the lumbar spine flexure in the coronal plane. However, one should keep in mind that such an approach, although favorable in terms of race performance, could negatively affect the canoeist’s health.

Keywords

  • sports training
  • spine flexion
  • health
  • competitive canoeists
Open Access

Bilateral and Unilateral Asymmetries of Isokinetic Strength and Flexibility in Male Young Professional Soccer Players

Published Online: 13 Apr 2013
Page range: 45 - 53

Abstract

This study investigated bilateral and unilateral asymmetries of strength and flexibility in male young professional soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) participated in this study. A Biodex Isokinetic Dynamometer was used to assess the hamstring and quadriceps strength at selected speeds of 60°/s, 180°/s and 300°/s. Hip joint flexibility was measured using a goniometer. No difference was observed in conventional strength ratio, dynamic control ratio and fast/slow speed ratio between the dominant and non-dominant legs (p>0.05). All but one of the players (97.2%) had musculoskeletal abnormality (bilateral imbalance > 10%) in one or more specific muscle groups. The dominant leg had greater hip joint flexibility compared with the non-dominant leg (108.8 ± 10.7° versus 104.6 ± 9.8°, respectively). The findings support the hypothesis that physical performance and movement pattern experienced during soccer playing may negatively change the balance of strength in both legs (bilateral strength balance), but not on the same leg of the young male professional soccer players. The results can be helpful for trainers and coaches to decide whether the players need to improve their balance and strength which in turn may prevent injury. It is suggested that in professional soccer training, quadriceps and hamstrings muscle strength, as well as hip joint flexibility should not be overlooked.

Keywords

  • isokinetic strength
  • flexibility
  • competitive soccer players
Open Access

Cardiorespiratory Fitness and Motor Skills in Relation to Cognition and Academic Performance in Children – A Review

Published Online: 13 Apr 2013
Page range: 55 - 68

Abstract

Different elements of physical fitness in children have shown a declining trend during the past few decades. Cardiorespiratory fitness and motor skills have been associated with cognition, but the magnitude of this association remains unknown. The purpose of this review is to provide an overview of the relationship of cardiorespiratory fitness and motor skills with cognitive functions and academic performance in children up to 13 years of age. Cross-sectional studies suggest that children with higher cardiorespiratory fitness have more efficient cognitive processing at the neuroelectric level, as well as larger hippocampal and basal ganglia volumes, compared to children with lower cardiorespiratory fitness. Higher cardiorespiratory fitness has been associated with better inhibitory control in tasks requiring rigorous attention allocation. Better motor skills have been related to more efficient cognitive functions including inhibitory control and working memory. Higher cardiorespiratory fitness and better motor skills have also been associated with better academic performance. Furthermore, none of the studies on cardiorespiratory fitness have revealed independent associations with cognitive functions by controlling for motor skills. Studies concerning the relationship between motor skills and cognitive functions also did not consider cardiorespiratory fitness in the analyses. The results of this review suggest that high levels of cardiorespiratory fitness and motor skills may be beneficial for cognitive development and academic performance but the evidence relies mainly on cross-sectional studies.

Keywords

  • physical fitness
  • movement skills
  • physical activity
  • children
  • scholastic achievement
Open Access

A Reliability of Electromyographic Normalization Methods for the Infraspinatus Muscle in Healthy Subjects

Published Online: 13 Apr 2013
Page range: 69 - 76

Abstract

The purpose of this study was to examine the test-retest reliability of normalization methods for the infraspinatus muscle in a group of healthy subjects. Twelve healthy subjects (male=8, female=4) performed the maximal voluntary isometric contraction (MVIC) with examiner`s resistance, MVIC with a digital tension-meter (MVIC-DT), and sub-MVIC methods. Surface electromyography (EMG) signals were recorded from the infraspinatus muscles according to normalization methods. Reliability was analyzed using the intra-class coefficient (ICC), standard error of measurement (SEM), and minimal detectable difference (MDD). The results of the present study demonstrated that the sub-MVIC method has excellent test-retest reliability (ICC=0.92) with a relatively small SEM (5.9 mV) and MDD95 (16.4 mV), compared to MVIC-DT (ICC=0.73; SEM=11.2 mV; MDD95: 31 mV) and MVIC-E (ICC=0.5; SEM=15.7 mV; MDD95: 43.6 mV). These findings provide evidence that sub-MVIC is more appropriate for comparing the EMG activity for the infraspinatus muscle as a normalization method. If MVIC for normalization is needed, MVIC-DT is more appropriate than MVIC-E.

Keywords e

  • lectromyography
  • infraspinatus muscle
  • normalization
  • reliability
Open Access

Anthropometric and Physical Fitness Differences Among Brazilian Adolescents who Practise Different Team Court Sports

Published Online: 13 Apr 2013
Page range: 77 - 86

Abstract

The objective of this work was to compare the anthropometric and physical fitness characteristics of Brazilian adolescents who practise team court sports and to compare specific parameters obtained for adolescents with data from the general population. This was a cross-sectional study of 1,348 male adolescents grouped as follows: basketball players (n = 287), indoor soccer players (n = 665), handball players (n = 108) and volleyball players (n = 288), all between 10 and 14 years of age. Anthropometric (body mass, body height, arm span, and body mass index) and physical fitness data (flexibility, muscular strength, explosive power, speed, aerobic fitness and agility) were collected. The Brazilian population was used as a reference and compared to the adolescent subjects using Z scores for all variables. Anthropometric characteristics and performances in physical fitness tests differed (p<0.05) among players of different sports. In addition, for each variable assessed, adolescents who practised team court sports showed similar or improved results compared to their counterparts in the general population (p<0.05). Furthermore, the anthropometric and physical fitness characteristics differed depending on the team court sport practised. These findings may elucidate which physical abilities are most impacted by the practise of a particular team sport as well as help teachers and physical education and sport professionals identify talented adolescents.

Keywords

  • sports performance
  • cross-sectional studies
  • anthropometric and fitness variables
  • youth
  • team court sports
Open Access

Temporal Activity in Particular Segments and Transitions in The Olympic Triathlon

Published Online: 13 Apr 2013
Page range: 87 - 95

Abstract

The Olympic Triathlon is a combined endurance sport. It includes back-to-back swimming, cycling, running and the transition between events (T1 & T2). The aim of the current study was to analyse the possible relationship between the Lost Time T1 & T2 and overall performance. The results showed that the percentages of total time corresponding to each part of the race were: 16.2% for swimming, 0.74% for the swimming-cycling transition (T1), 53.07% for cycling, 0.47% for the cycling-running transition (T2) and 29.5% for running. The correlations between each part of the race and the final placing were: r=0.36 for swimming, r=0.25 for T1, r=0.62 for the cycling, r=0.33 for T2, and r=0.83 for the running. Also, values of r=0.34 & r=0.43 were obtained for Lost Time T1 and Lost Time T2, respectively. In conclusion, losing less time during T2 has been demonstrated to be related to obtaining a better final result.

Keywords

  • cycle-run transition
  • swim-bike transition
  • triathlon
Open Access

Offensive Sequences in Youth Soccer: Effects of Experience and Small-Sided Games

Published Online: 13 Apr 2013
Page range: 97 - 106

Abstract

The present study aimed to analyze the interaction and main effects of deliberate practice experience and smallsided game format (3 vs. 3 and 6 vs. 6 plus goalkeepers) on the offensive performance of young soccer players. Twentyeight U-15 male players were divided into 2 groups according to their deliberate practice experience in soccer (i.e., years of experience in federation soccer): Non-Experienced (age: 12.84 ± 0.63 years) and Experienced (age: 12.91 ± 0.59 years; experience: 3.93 ± 1.00 years). The experimental protocol consisted of 3 independent sessions separated by one-week intervals. In each session both groups performed each small-sided game during 10 minutes interspersed with 5 minutes of passive recovery. To characterize the recorded offensive sequences we used the Offensive Sequences Characterization System, which includes performance indicators previous applied in other studies. No interaction effects on the offensive performance were found between both factors. Non-parametric MANOVA revealed that the factor “experience level” had a significant effect (p<0.05) on performance indicators that characterize the development of offensive sequences, especially in 6 vs. 6 + GKs. While experienced players produced longer offensive sequences with greater ball circulation between them, the non-experienced participants performed faster offensive sequences with a predominance of individual actions. Furthermore, significant differences were observed (p<0.05) in the development and finalization of offensive sequences within each group, when comparing small-sided game formats. Evidence supports that small-sided games can serve several purposes as specific means of training. However, the manipulation of game format should always consider the players’ individual constraints.

Keywords

  • association football
  • constraints-led approach
  • performance
  • skill acquisition
Open Access

The Structure of Performance of a Sport Rock Climber

Published Online: 13 Apr 2013
Page range: 107 - 117

Abstract

This study is a contribution to the discussion about the structure of performance of sport rock climbers. Because of the complex and multifaceted nature of this sport, multivariate statistics were applied in the study. The subjects included thirty experienced sport climbers. Forty three variables were scrutinised, namely somatic characteristics, specific physical fitness, coordination abilities, aerobic and anaerobic power, technical and tactical skills, mental characteristics, as well as 2 variables describing the climber’s performance in the OS (Max OS) and RP style (Max RP). The results show that for training effectiveness of advanced climbers to be thoroughly analysed and examined, tests assessing their physical, technical and mental characteristics are necessary. The three sets of variables used in this study explained the structure of performance similarly, but not identically (in 38, 33 and 25%, respectively). They were also complementary to around 30% of the variance. The overall performance capacity of a sport rock climber (Max OS and Max RP) was also evaluated in the study. The canonical weights of the dominant first canonical root were 0.554 and 0.512 for Max OS and Max RP, respectively. Despite the differences between the two styles of climbing, seven variables - the maximal relative strength of the fingers (canonical weight = 0.490), mental endurance (one of scales : The Formal Characteristics of Behaviour-Temperament Inventory (FCB-TI; Strelau and Zawadzki, 1995)) (-0.410), climbing technique (0.370), isometric endurance of the fingers (0.340), the number of errors in the complex reaction time test (- 0.319), the ape index (-0.319) and oxygen uptake during arm work at the anaerobic threshold (0.254) were found to explain 77% of performance capacity common to the two styles.

Keywords

  • sport climbing
  • canonical analysis
  • structure of performance
Open Access

The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

Published Online: 13 Apr 2013
Page range: 119 - 126

Abstract

The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photocells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=-2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=-1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=-1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=-1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers.

Keywords

  • resistance training
  • high-level hurdlers
  • muscular strength
  • athletics
  • testing
Open Access

Influence of Inter-Set Stretching on Strength, Flexibility and Hormonal Adaptations

Published Online: 13 Apr 2013
Page range: 127 - 135

Abstract

Adequate levels of strength and flexibility are important for the promotion and maintenance of health and functional autonomy as well as safe and effective sports participation. The aim of the present study was to analyze the effects of 8 weeks of strength training with or without inter-set static stretching on strength, flexibility and hormonal adaptations of trained men. Sixteen trained men were randomly divided into 2 groups: the static stretching group (SSG) and passive interval group (PIG). All participants performed 24 training sessions 3 times a week. The test and retest of 8RM, strength, flexibility, cortisol and growth hormone concentration in pre and post test conditions were also evaluated. To compare the differences between and within groups in pre- and post-training tests, ANOVA with repeated measures was performed (SSGpre x SSGpost; PIGpre x PIGpost; SSGpost x PIGpost). An alpha level of p<0.05 was considered statistically significant for all comparisons. Both groups showed significant increases in strength (SSGpre vs. SSGpost; PIGpre vs. PIGpost) in the same exercises for leg extension (LE) and Low Row (LR). Specifically, in the SSG group, the parameters for LE were (p = 0.0015 and ES = 2.28 - Large), and the parameters for LR were (p = 0.002 and ES = 1.95 - Large). Moreover, in the PIG group, the parameters for LE were (p = 0.009 and ES = 1.95 - Large), and the parameters for LR were (p = 0.0001 and ES = 2.88 - Large). No differences were found between the groups (SSGpost vs. PIGpost). Both groups showed significant increases in flexibility but in different joints (SSGpre vs. SSGpost; PIGpre vs. PIGpost). In the SSG group, only three joints showed significant increases in flexibility: shoulder extension (p = 0.004 and ES = 1.76 - Large), torso flexion (p = 0.002 and ES = 2.36 - Large), and hip flexion (p = 0.001 and ES = 1.79 - Large). In the PIG group, only three joints showed increases in flexibility: horizontal shoulder abduction (p = 0.003 and ES = 2.07 - Large), hip flexion (p = 0.001 and ES = 2.39 - Large), and hip extension (p = 0.02 and ES = 1.79 - Large). In-between group analyses (SSGpost x PIGpost) revealed differences in two joints: shoulder extension (p = 0.001) and horizontal shoulder abduction (p = 0.001). Hormonal profiles showed no significant differences in cortisol secretion or growth hormone concentration. In conclusion, both studied strength protocols (with and without inter-set static stretching) resulted in flexibility and strength gains without an effect on the anabolic and catabolic hormonal profile.

Keywords

  • strength performance
  • static stretching
  • cortisol
  • growth hormone
  • flexibility
Open Access

Game Performance Versus Competitive Performance in the World Championship of Handball 2011

Published Online: 13 Apr 2013
Page range: 137 - 147

Abstract

This article assesses the game performance of the teams participating in the Men’s World Championship of Handball of 2011 by using Data Envelopment Analysis (DEA) and the cross-efficiency evaluation. DEA uses Linear Programming to yield a measure of the overall performance of the game of particular teams, and allows us to identify relative strengths and weaknesses by means of benchmarking analysis. The cross-efficiency evaluation provides a peerappraisal of the teams with different patterns of game, and makes it possible to rank them. Comparisons between this ranking and the final classification in the championship provide an insight into the game performance of the teams versus their competitive performance. We highlight the fact that France, which is the world champion, is also identified as an “all-round” performer in our game performance assessment.

Keywords

  • team game performance
  • Data Envelopment Analysis
  • cross-efficiency evaluation
  • handball
Open Access

A Kinematics Analysis Of Three Best 100 M Performances Ever

Published Online: 13 Apr 2013
Page range: 149 - 160

Abstract

The purpose of this investigation was to compare and determine the relevance of the morphological characteristics and variability of running speed parameters (stride length and stride frequency) between Usain Bolt’s three best 100 m performances. Based on this, an attempt was made to define which factors determine the performance of Usain Bolt's sprint and, therefore, distinguish him from other sprinters. We analyzed the previous world record of 9.69 s set in the 2008 Beijing Olympics, the current record of 9.58 s set in the 2009 Berlin World Championships in Athletics and the O lympic record of 9.63 s set in 2012 London Olympics Games by Usain Bolt. The application of VirtualDub Programme allowed the acquisition of basic kinematical variables such as step length and step frequency parameters of 100 m sprint from video footage provided by NBC TV station, BBC TV station. This data was compared with other data available on the web and data published by the Scientific Research Project Office responsible on behalf of IAAF and the German Athletics Association (DVL). The main hypothesis was that the step length is the main factor that determines running speed in the 10 and 20 m sections of the entire 100 m distance. Bolt’s anthropometric advantage (body height, leg length and liner body) is not questionable and it is one of the factors that makes him faster than the rest of the finalists from each three competitions. Additionally, Bolt’s 20 cm longer stride shows benefit in the latter part of the race. Despite these factors, he is probably able to strike the ground more forcefully than rest of sprinters, relative to their body mass, therefore, he might maximize his time on the ground and to exert the same force over this period of time. This ability, combined with longer stride allows him to create very high running speed - over 12 m/s (12.05 -12.34 m/s) in some 10 m sections of his three 100 m performances. These assumption confirmed the application of Ballerieich's formula for speed development. In most 10 m sections of the 100 m sprint, the step length was the parameter that significantly determined the increase of maximal running speed, therefore, distinguishing Bolt from the other finalists.

Keywords

  • sprinting
  • world record
  • kinematic analysis
  • anthropometric characteristics
Open Access

Identifying Basketball Performance Indicators in Regular Season and Playoff Games

Published Online: 13 Apr 2013
Page range: 161 - 168

Abstract

The aim of the present study was to identify basketball game performance indicators which best discriminate winners and losers in regular season and playoffs. The sample used was composed by 323 games of ACB Spanish Basketball League from the regular season (n=306) and from the playoffs (n=17). A previous cluster analysis allowed splitting the sample in balanced (equal or below 12 points), unbalanced (between 13 and 28 points) and very unbalanced games (above 28 points). A discriminant analysis was used to identify the performance indicators either in regular season and playoff games. In regular season games, the winning teams dominated in assists, defensive rebounds, successful 2 and 3-point field-goals. However, in playoff games the winning teams’ superiority was only in defensive rebounding. In practical applications, these results may help the coaches to accurately design training programs to reflect the importance of having different offensive set plays and also have specific conditioning programs to prepare for defensive rebounding.

Keywords

  • Performance analysis
  • game-indicators
  • win/lose
  • basketball
Open Access

The Importance of Parents’ Behavior in their Children’s Enjoyment and Amotivation in Sports

Published Online: 13 Apr 2013
Page range: 169 - 177

Abstract

The main aim of the research was to examine the relationship between motivational orientations and parents’ behavior with regard to the players’ motivational orientation, motivational climate, enjoyment and amotivation. The sample comprised 723 athletes (M = 12.37, SD = 1.48) and 723 parents (M = 46.46, SD = 2.56). Players were male and female who belonged to federative basketball, handball, football and volleyball teams. Parents and athletes completed questionnaires that assessed motivational orientations, parents’ involvement in the practice as well as enjoyment and motivation in the sport. Results showed a positive relationship between parents’ support of the sport and players’ enjoyment and a negative relationship with players’ amotivation. Moreover, in players who perceived more pressure from their parents, there was a positive association with amotivation and a negative one with enjoyment. Lastly, it was emphasized that appropriate parental participation can promote an increase of players’ enjoyment of and motivation for sport

Keywords

  • team sports
  • amotivation
  • athletes
  • family
Open Access

Interpersonal Dynamics: 1v1 Sub-Phase at Sub-18 Football Players

Published Online: 13 Apr 2013
Page range: 179 - 189

Abstract

The performance of football players within game context can be analyzed based on their ability to break or (re)balance the attacker-defender dyad. In this context, the analysis of each sub-phase (e.g., 1v1, 2v2) presents a feature that needs to be taken into account in sports analysis. This study aims to investigate the interpersonal dynamics dyad formed by the attacker and the defender in 1v1 situations with a goalkeeper. A sample of 11 football male players (age: 17.91 ± 1.04 years) with 8.6 ± 1.52 years of practice experience participated in the study. Analyzing the 1v1 sub-phase, results show that the distance, speed and angular amplitude between the attacker and the defender increases, especially when the attacker attempts to overtake the defender (i.e., score a goal). We conclude that decision-making emerges from the perception that players draw from the action, actively and consistently interacting to find solutions to emerging problems within the game context

Keywords

  • sport analysis
  • constraints
  • instruction
  • interpersonal dynamics
  • football
18 Articles
Open Access

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

Published Online: 13 Apr 2013
Page range: 5 - 160

Abstract

Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., 'to hold' vs. 'to pull') can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely, the effects of handedness could be relatively week showing only slight lagging of GF in the non-dominant, but not in the dominant hand. The presented findings reveal important aspects of hand function as seen through GF-LF coordination. Specifically, the use of specific hand areas for grasping, calculation of particular safety margins, the role of LF frequency (but not of LF range) and the effects of given instructions should be all taken into account when conducting future studies of manipulation tasks, standardizing their procedures and designing routine clinical tests of hand function.

Keywords

  • grip force
  • load force
  • coupling
  • scaling
  • modulation
Open Access

Short-Term High Intensity Plyometric Training Program Improves Strength, Power and Agility in Male Soccer Players

Published Online: 13 Apr 2013
Page range: 17 - 26

Abstract

The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.

Keywords

  • knee extensors
  • depth jump
  • dynamometer
  • unilateral
  • plyometrics
Open Access

Effect of Yellow-Tinted Lenses on Visual Attributes Related to Sports Activities

Published Online: 13 Apr 2013
Page range: 27 - 36

Abstract

The purpose of this study was to clarify the effect of colored lenses on visual attributes related to sports activities. The subjects were 24 students (11 females, 13 males; average age 21.0 ±1.2 years) attending a sports university. Lenses of 5 colors were used: colorless, light yellow, dark yellow, light gray, and dark gray. For each lens, measurements were performed in a fixed order: contrast sensitivity, dynamic visual acuity, depth perception, hand-eye coordination and visual acuity and low-contrast visual acuity. The conditions for the measurements of visual acuity and low-contrast visual acuity were in the order of Evening, Evening+Glare, Day, and Day+Glare. There were no significant differences among lenses in dynamic visual acuity and depth perception. For hand-eye coordination, time was significantly shorter with colorless than dark gray lenses. Contrast sensitivity was significantly higher with colorless, light yellow, and light gray lenses than with dark yellow and dark gray lenses. The low-contrast visual acuity test in the Day+Glare condition showed no significant difference among the lenses. In the Evening condition, lowcontrast visual acuity was significantly higher with colorless and light yellow lenses than with dark gray lenses, and in the Evening+Glare condition, low-contrast visual acuity was significantly higher with colorless lenses than with the other colors except light yellow. Under early evening conditions and during sports activities, light yellow lenses do not appear to have an adverse effect on visual attributes.

Keywords

  • sports
  • low-contrast visual acuity
  • contrast sensitivity
  • dynamic visual acuity
Open Access

Asymmetry of Spinal Segments Mobility in Canoeists and its Relationship with Racing Speed

Published Online: 13 Apr 2013
Page range: 37 - 43

Abstract

The aim of this study was to determine the extent of asymmetry of spinal segment mobility in canoeists. Moreover, the relationship between this parameter and racing speed was analyzed. The study included 18 canoeists with a mean age of 16.4 years. Mobility of cervical, thoracic and lumbar spine, in sagittal, coronal and transverse planes, was measured with the aid of a tensometric electrogoniometer. The racing speed was based on results achieved during the qualifying competition for the Polish national team. Spinal mobility was measured within two days after the competition. Significant associations were observed between average racing speed and the asymmetry coefficients of the cervical (r=-0.52; p=0.03) and lumbar spinal flexure in the coronal plane (r=0.57; p=0.01). The extent of the asymmetry of the cervical spine flexure in the coronal plane should possibly be reduced, because such asymmetry exerts a negative effect on racing speed. In contrast, canoeist’s training should be oriented towards increasing the asymmetry of the lumbar spine flexure in the coronal plane. However, one should keep in mind that such an approach, although favorable in terms of race performance, could negatively affect the canoeist’s health.

Keywords

  • sports training
  • spine flexion
  • health
  • competitive canoeists
Open Access

Bilateral and Unilateral Asymmetries of Isokinetic Strength and Flexibility in Male Young Professional Soccer Players

Published Online: 13 Apr 2013
Page range: 45 - 53

Abstract

This study investigated bilateral and unilateral asymmetries of strength and flexibility in male young professional soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) participated in this study. A Biodex Isokinetic Dynamometer was used to assess the hamstring and quadriceps strength at selected speeds of 60°/s, 180°/s and 300°/s. Hip joint flexibility was measured using a goniometer. No difference was observed in conventional strength ratio, dynamic control ratio and fast/slow speed ratio between the dominant and non-dominant legs (p>0.05). All but one of the players (97.2%) had musculoskeletal abnormality (bilateral imbalance > 10%) in one or more specific muscle groups. The dominant leg had greater hip joint flexibility compared with the non-dominant leg (108.8 ± 10.7° versus 104.6 ± 9.8°, respectively). The findings support the hypothesis that physical performance and movement pattern experienced during soccer playing may negatively change the balance of strength in both legs (bilateral strength balance), but not on the same leg of the young male professional soccer players. The results can be helpful for trainers and coaches to decide whether the players need to improve their balance and strength which in turn may prevent injury. It is suggested that in professional soccer training, quadriceps and hamstrings muscle strength, as well as hip joint flexibility should not be overlooked.

Keywords

  • isokinetic strength
  • flexibility
  • competitive soccer players
Open Access

Cardiorespiratory Fitness and Motor Skills in Relation to Cognition and Academic Performance in Children – A Review

Published Online: 13 Apr 2013
Page range: 55 - 68

Abstract

Different elements of physical fitness in children have shown a declining trend during the past few decades. Cardiorespiratory fitness and motor skills have been associated with cognition, but the magnitude of this association remains unknown. The purpose of this review is to provide an overview of the relationship of cardiorespiratory fitness and motor skills with cognitive functions and academic performance in children up to 13 years of age. Cross-sectional studies suggest that children with higher cardiorespiratory fitness have more efficient cognitive processing at the neuroelectric level, as well as larger hippocampal and basal ganglia volumes, compared to children with lower cardiorespiratory fitness. Higher cardiorespiratory fitness has been associated with better inhibitory control in tasks requiring rigorous attention allocation. Better motor skills have been related to more efficient cognitive functions including inhibitory control and working memory. Higher cardiorespiratory fitness and better motor skills have also been associated with better academic performance. Furthermore, none of the studies on cardiorespiratory fitness have revealed independent associations with cognitive functions by controlling for motor skills. Studies concerning the relationship between motor skills and cognitive functions also did not consider cardiorespiratory fitness in the analyses. The results of this review suggest that high levels of cardiorespiratory fitness and motor skills may be beneficial for cognitive development and academic performance but the evidence relies mainly on cross-sectional studies.

Keywords

  • physical fitness
  • movement skills
  • physical activity
  • children
  • scholastic achievement
Open Access

A Reliability of Electromyographic Normalization Methods for the Infraspinatus Muscle in Healthy Subjects

Published Online: 13 Apr 2013
Page range: 69 - 76

Abstract

The purpose of this study was to examine the test-retest reliability of normalization methods for the infraspinatus muscle in a group of healthy subjects. Twelve healthy subjects (male=8, female=4) performed the maximal voluntary isometric contraction (MVIC) with examiner`s resistance, MVIC with a digital tension-meter (MVIC-DT), and sub-MVIC methods. Surface electromyography (EMG) signals were recorded from the infraspinatus muscles according to normalization methods. Reliability was analyzed using the intra-class coefficient (ICC), standard error of measurement (SEM), and minimal detectable difference (MDD). The results of the present study demonstrated that the sub-MVIC method has excellent test-retest reliability (ICC=0.92) with a relatively small SEM (5.9 mV) and MDD95 (16.4 mV), compared to MVIC-DT (ICC=0.73; SEM=11.2 mV; MDD95: 31 mV) and MVIC-E (ICC=0.5; SEM=15.7 mV; MDD95: 43.6 mV). These findings provide evidence that sub-MVIC is more appropriate for comparing the EMG activity for the infraspinatus muscle as a normalization method. If MVIC for normalization is needed, MVIC-DT is more appropriate than MVIC-E.

Keywords e

  • lectromyography
  • infraspinatus muscle
  • normalization
  • reliability
Open Access

Anthropometric and Physical Fitness Differences Among Brazilian Adolescents who Practise Different Team Court Sports

Published Online: 13 Apr 2013
Page range: 77 - 86

Abstract

The objective of this work was to compare the anthropometric and physical fitness characteristics of Brazilian adolescents who practise team court sports and to compare specific parameters obtained for adolescents with data from the general population. This was a cross-sectional study of 1,348 male adolescents grouped as follows: basketball players (n = 287), indoor soccer players (n = 665), handball players (n = 108) and volleyball players (n = 288), all between 10 and 14 years of age. Anthropometric (body mass, body height, arm span, and body mass index) and physical fitness data (flexibility, muscular strength, explosive power, speed, aerobic fitness and agility) were collected. The Brazilian population was used as a reference and compared to the adolescent subjects using Z scores for all variables. Anthropometric characteristics and performances in physical fitness tests differed (p<0.05) among players of different sports. In addition, for each variable assessed, adolescents who practised team court sports showed similar or improved results compared to their counterparts in the general population (p<0.05). Furthermore, the anthropometric and physical fitness characteristics differed depending on the team court sport practised. These findings may elucidate which physical abilities are most impacted by the practise of a particular team sport as well as help teachers and physical education and sport professionals identify talented adolescents.

Keywords

  • sports performance
  • cross-sectional studies
  • anthropometric and fitness variables
  • youth
  • team court sports
Open Access

Temporal Activity in Particular Segments and Transitions in The Olympic Triathlon

Published Online: 13 Apr 2013
Page range: 87 - 95

Abstract

The Olympic Triathlon is a combined endurance sport. It includes back-to-back swimming, cycling, running and the transition between events (T1 & T2). The aim of the current study was to analyse the possible relationship between the Lost Time T1 & T2 and overall performance. The results showed that the percentages of total time corresponding to each part of the race were: 16.2% for swimming, 0.74% for the swimming-cycling transition (T1), 53.07% for cycling, 0.47% for the cycling-running transition (T2) and 29.5% for running. The correlations between each part of the race and the final placing were: r=0.36 for swimming, r=0.25 for T1, r=0.62 for the cycling, r=0.33 for T2, and r=0.83 for the running. Also, values of r=0.34 & r=0.43 were obtained for Lost Time T1 and Lost Time T2, respectively. In conclusion, losing less time during T2 has been demonstrated to be related to obtaining a better final result.

Keywords

  • cycle-run transition
  • swim-bike transition
  • triathlon
Open Access

Offensive Sequences in Youth Soccer: Effects of Experience and Small-Sided Games

Published Online: 13 Apr 2013
Page range: 97 - 106

Abstract

The present study aimed to analyze the interaction and main effects of deliberate practice experience and smallsided game format (3 vs. 3 and 6 vs. 6 plus goalkeepers) on the offensive performance of young soccer players. Twentyeight U-15 male players were divided into 2 groups according to their deliberate practice experience in soccer (i.e., years of experience in federation soccer): Non-Experienced (age: 12.84 ± 0.63 years) and Experienced (age: 12.91 ± 0.59 years; experience: 3.93 ± 1.00 years). The experimental protocol consisted of 3 independent sessions separated by one-week intervals. In each session both groups performed each small-sided game during 10 minutes interspersed with 5 minutes of passive recovery. To characterize the recorded offensive sequences we used the Offensive Sequences Characterization System, which includes performance indicators previous applied in other studies. No interaction effects on the offensive performance were found between both factors. Non-parametric MANOVA revealed that the factor “experience level” had a significant effect (p<0.05) on performance indicators that characterize the development of offensive sequences, especially in 6 vs. 6 + GKs. While experienced players produced longer offensive sequences with greater ball circulation between them, the non-experienced participants performed faster offensive sequences with a predominance of individual actions. Furthermore, significant differences were observed (p<0.05) in the development and finalization of offensive sequences within each group, when comparing small-sided game formats. Evidence supports that small-sided games can serve several purposes as specific means of training. However, the manipulation of game format should always consider the players’ individual constraints.

Keywords

  • association football
  • constraints-led approach
  • performance
  • skill acquisition
Open Access

The Structure of Performance of a Sport Rock Climber

Published Online: 13 Apr 2013
Page range: 107 - 117

Abstract

This study is a contribution to the discussion about the structure of performance of sport rock climbers. Because of the complex and multifaceted nature of this sport, multivariate statistics were applied in the study. The subjects included thirty experienced sport climbers. Forty three variables were scrutinised, namely somatic characteristics, specific physical fitness, coordination abilities, aerobic and anaerobic power, technical and tactical skills, mental characteristics, as well as 2 variables describing the climber’s performance in the OS (Max OS) and RP style (Max RP). The results show that for training effectiveness of advanced climbers to be thoroughly analysed and examined, tests assessing their physical, technical and mental characteristics are necessary. The three sets of variables used in this study explained the structure of performance similarly, but not identically (in 38, 33 and 25%, respectively). They were also complementary to around 30% of the variance. The overall performance capacity of a sport rock climber (Max OS and Max RP) was also evaluated in the study. The canonical weights of the dominant first canonical root were 0.554 and 0.512 for Max OS and Max RP, respectively. Despite the differences between the two styles of climbing, seven variables - the maximal relative strength of the fingers (canonical weight = 0.490), mental endurance (one of scales : The Formal Characteristics of Behaviour-Temperament Inventory (FCB-TI; Strelau and Zawadzki, 1995)) (-0.410), climbing technique (0.370), isometric endurance of the fingers (0.340), the number of errors in the complex reaction time test (- 0.319), the ape index (-0.319) and oxygen uptake during arm work at the anaerobic threshold (0.254) were found to explain 77% of performance capacity common to the two styles.

Keywords

  • sport climbing
  • canonical analysis
  • structure of performance
Open Access

The Effects of a Maximal Power Training Cycle on the Strength, Maximum Power, Vertical Jump Height and Acceleration of High-Level 400-Meter Hurdlers

Published Online: 13 Apr 2013
Page range: 119 - 126

Abstract

The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photocells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=-2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=-1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=-1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=-1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers.

Keywords

  • resistance training
  • high-level hurdlers
  • muscular strength
  • athletics
  • testing
Open Access

Influence of Inter-Set Stretching on Strength, Flexibility and Hormonal Adaptations

Published Online: 13 Apr 2013
Page range: 127 - 135

Abstract

Adequate levels of strength and flexibility are important for the promotion and maintenance of health and functional autonomy as well as safe and effective sports participation. The aim of the present study was to analyze the effects of 8 weeks of strength training with or without inter-set static stretching on strength, flexibility and hormonal adaptations of trained men. Sixteen trained men were randomly divided into 2 groups: the static stretching group (SSG) and passive interval group (PIG). All participants performed 24 training sessions 3 times a week. The test and retest of 8RM, strength, flexibility, cortisol and growth hormone concentration in pre and post test conditions were also evaluated. To compare the differences between and within groups in pre- and post-training tests, ANOVA with repeated measures was performed (SSGpre x SSGpost; PIGpre x PIGpost; SSGpost x PIGpost). An alpha level of p<0.05 was considered statistically significant for all comparisons. Both groups showed significant increases in strength (SSGpre vs. SSGpost; PIGpre vs. PIGpost) in the same exercises for leg extension (LE) and Low Row (LR). Specifically, in the SSG group, the parameters for LE were (p = 0.0015 and ES = 2.28 - Large), and the parameters for LR were (p = 0.002 and ES = 1.95 - Large). Moreover, in the PIG group, the parameters for LE were (p = 0.009 and ES = 1.95 - Large), and the parameters for LR were (p = 0.0001 and ES = 2.88 - Large). No differences were found between the groups (SSGpost vs. PIGpost). Both groups showed significant increases in flexibility but in different joints (SSGpre vs. SSGpost; PIGpre vs. PIGpost). In the SSG group, only three joints showed significant increases in flexibility: shoulder extension (p = 0.004 and ES = 1.76 - Large), torso flexion (p = 0.002 and ES = 2.36 - Large), and hip flexion (p = 0.001 and ES = 1.79 - Large). In the PIG group, only three joints showed increases in flexibility: horizontal shoulder abduction (p = 0.003 and ES = 2.07 - Large), hip flexion (p = 0.001 and ES = 2.39 - Large), and hip extension (p = 0.02 and ES = 1.79 - Large). In-between group analyses (SSGpost x PIGpost) revealed differences in two joints: shoulder extension (p = 0.001) and horizontal shoulder abduction (p = 0.001). Hormonal profiles showed no significant differences in cortisol secretion or growth hormone concentration. In conclusion, both studied strength protocols (with and without inter-set static stretching) resulted in flexibility and strength gains without an effect on the anabolic and catabolic hormonal profile.

Keywords

  • strength performance
  • static stretching
  • cortisol
  • growth hormone
  • flexibility
Open Access

Game Performance Versus Competitive Performance in the World Championship of Handball 2011

Published Online: 13 Apr 2013
Page range: 137 - 147

Abstract

This article assesses the game performance of the teams participating in the Men’s World Championship of Handball of 2011 by using Data Envelopment Analysis (DEA) and the cross-efficiency evaluation. DEA uses Linear Programming to yield a measure of the overall performance of the game of particular teams, and allows us to identify relative strengths and weaknesses by means of benchmarking analysis. The cross-efficiency evaluation provides a peerappraisal of the teams with different patterns of game, and makes it possible to rank them. Comparisons between this ranking and the final classification in the championship provide an insight into the game performance of the teams versus their competitive performance. We highlight the fact that France, which is the world champion, is also identified as an “all-round” performer in our game performance assessment.

Keywords

  • team game performance
  • Data Envelopment Analysis
  • cross-efficiency evaluation
  • handball
Open Access

A Kinematics Analysis Of Three Best 100 M Performances Ever

Published Online: 13 Apr 2013
Page range: 149 - 160

Abstract

The purpose of this investigation was to compare and determine the relevance of the morphological characteristics and variability of running speed parameters (stride length and stride frequency) between Usain Bolt’s three best 100 m performances. Based on this, an attempt was made to define which factors determine the performance of Usain Bolt's sprint and, therefore, distinguish him from other sprinters. We analyzed the previous world record of 9.69 s set in the 2008 Beijing Olympics, the current record of 9.58 s set in the 2009 Berlin World Championships in Athletics and the O lympic record of 9.63 s set in 2012 London Olympics Games by Usain Bolt. The application of VirtualDub Programme allowed the acquisition of basic kinematical variables such as step length and step frequency parameters of 100 m sprint from video footage provided by NBC TV station, BBC TV station. This data was compared with other data available on the web and data published by the Scientific Research Project Office responsible on behalf of IAAF and the German Athletics Association (DVL). The main hypothesis was that the step length is the main factor that determines running speed in the 10 and 20 m sections of the entire 100 m distance. Bolt’s anthropometric advantage (body height, leg length and liner body) is not questionable and it is one of the factors that makes him faster than the rest of the finalists from each three competitions. Additionally, Bolt’s 20 cm longer stride shows benefit in the latter part of the race. Despite these factors, he is probably able to strike the ground more forcefully than rest of sprinters, relative to their body mass, therefore, he might maximize his time on the ground and to exert the same force over this period of time. This ability, combined with longer stride allows him to create very high running speed - over 12 m/s (12.05 -12.34 m/s) in some 10 m sections of his three 100 m performances. These assumption confirmed the application of Ballerieich's formula for speed development. In most 10 m sections of the 100 m sprint, the step length was the parameter that significantly determined the increase of maximal running speed, therefore, distinguishing Bolt from the other finalists.

Keywords

  • sprinting
  • world record
  • kinematic analysis
  • anthropometric characteristics
Open Access

Identifying Basketball Performance Indicators in Regular Season and Playoff Games

Published Online: 13 Apr 2013
Page range: 161 - 168

Abstract

The aim of the present study was to identify basketball game performance indicators which best discriminate winners and losers in regular season and playoffs. The sample used was composed by 323 games of ACB Spanish Basketball League from the regular season (n=306) and from the playoffs (n=17). A previous cluster analysis allowed splitting the sample in balanced (equal or below 12 points), unbalanced (between 13 and 28 points) and very unbalanced games (above 28 points). A discriminant analysis was used to identify the performance indicators either in regular season and playoff games. In regular season games, the winning teams dominated in assists, defensive rebounds, successful 2 and 3-point field-goals. However, in playoff games the winning teams’ superiority was only in defensive rebounding. In practical applications, these results may help the coaches to accurately design training programs to reflect the importance of having different offensive set plays and also have specific conditioning programs to prepare for defensive rebounding.

Keywords

  • Performance analysis
  • game-indicators
  • win/lose
  • basketball
Open Access

The Importance of Parents’ Behavior in their Children’s Enjoyment and Amotivation in Sports

Published Online: 13 Apr 2013
Page range: 169 - 177

Abstract

The main aim of the research was to examine the relationship between motivational orientations and parents’ behavior with regard to the players’ motivational orientation, motivational climate, enjoyment and amotivation. The sample comprised 723 athletes (M = 12.37, SD = 1.48) and 723 parents (M = 46.46, SD = 2.56). Players were male and female who belonged to federative basketball, handball, football and volleyball teams. Parents and athletes completed questionnaires that assessed motivational orientations, parents’ involvement in the practice as well as enjoyment and motivation in the sport. Results showed a positive relationship between parents’ support of the sport and players’ enjoyment and a negative relationship with players’ amotivation. Moreover, in players who perceived more pressure from their parents, there was a positive association with amotivation and a negative one with enjoyment. Lastly, it was emphasized that appropriate parental participation can promote an increase of players’ enjoyment of and motivation for sport

Keywords

  • team sports
  • amotivation
  • athletes
  • family
Open Access

Interpersonal Dynamics: 1v1 Sub-Phase at Sub-18 Football Players

Published Online: 13 Apr 2013
Page range: 179 - 189

Abstract

The performance of football players within game context can be analyzed based on their ability to break or (re)balance the attacker-defender dyad. In this context, the analysis of each sub-phase (e.g., 1v1, 2v2) presents a feature that needs to be taken into account in sports analysis. This study aims to investigate the interpersonal dynamics dyad formed by the attacker and the defender in 1v1 situations with a goalkeeper. A sample of 11 football male players (age: 17.91 ± 1.04 years) with 8.6 ± 1.52 years of practice experience participated in the study. Analyzing the 1v1 sub-phase, results show that the distance, speed and angular amplitude between the attacker and the defender increases, especially when the attacker attempts to overtake the defender (i.e., score a goal). We conclude that decision-making emerges from the perception that players draw from the action, actively and consistently interacting to find solutions to emerging problems within the game context

Keywords

  • sport analysis
  • constraints
  • instruction
  • interpersonal dynamics
  • football

Plan your remote conference with Sciendo