Asian Journal of Sports Medicine
Volume:8 Issue: 4, Dec 2017

Short sprint is an important physical ability that determines the success in various sports modalities and may influence different conditioning activities. Postactivation potentiation (PAP) is a conditioning method used in practicing sports, which can result in acute improvements in muscle power and performance by interaction of physiological and neural mechanisms.
The current study aimed at investigating the effect of PAP on a sprint of less than 40 meters.
A systematic review and meta-analysis was conducted on the randomized, controlled studies. The search was conducted in several databases (PubMed, Web of Science, Cochrane, and Science Direct) using the following keywords: “Postactivation Potentiation”, “Sprint”, and “Complex Training and Sprint”. The sprint time data (mean and standard deviation) of the selected studies were analyzed using the OpenMeta (Analyst)® program. Data were expressed as weighted mean differences (WMD) between the groups with 95% confidence interval (95% CI). The level of significance was P A total of 1859 records were initially identified out of which 15 studies were selected according to the inclusion criteria and included in the current study. The meta-analysis results showed a positive effect of PAP on sprint time in the distance 0 to 10 meter (WMD = -0.031 seconds, 95% CI: -0.050, -0.012, P = 0.001), 11 to 20 meter (WMD = -0.048 seconds, 95% CI: -0.089, -0.007, P = 0.021), 21 to 30 meter (WMD = -0.060 seconds, 95% CI: -0.094, -0.026; P In summary, PAP induced positive effects on short sprint performances.

Alpine skiing has high rates of knee injuries. Prophylactic knee braces (PKBs) and functional knee braces (FKBs) are often prescribed by clinicians to reduce injuries or re-injuries in skiers.
This literature review evaluates current knowledge on the biomechanical and clinical effectiveness of prophylactic and functional knee braces in preventing knee injuries and their impact on the athletic performance of non-injured and injured individuals.
A literature review was performed to analyze the efficiency of knee braces concerning the reduction of mechanical stress, influence on muscle control, performance and injury prevention.
Most of the available literature describes research on the use of knee braces in contact sports, specifically American football. In this context, several studies show braces to be more effective in preventing medial collateral ligament injuries than anterior cruciate ligament injuries in both cadaveric and clinical studies. The use of functional braces after anterior cruciate ligament reconstruction has been supported and refuted in both postoperative and long-term studies. Ski-specific studies show a positive effect of knee braces on proprioception; no influence on performance; and a protective effect on previously injured skiers.
Current literature indicates PKBs may have a protective function in healthy patients, while influence on performance is minimal. Functional braces are recommended in ACL-deficient patients and are biomechanically effective under low-loading conditions. They may not be as effective in high-loading conditions, such as athletic activity. There is a protective effect of FKBs of preventing re-rupture of reconstructed ACLs and preventing further knee injuries on ACL-deficient knees in skiers. More research is needed to determine the effectiveness of PKBs snow sports.

Jump analyses are frequently conducted in the sport and rehabilitation sector by different methods. This study aimed to compare a new ultrasonic system (US) measuring the distance between standing and the highest point of the jump with (a) the impulse-momentum (FP_IM), double integration (FP_DI), and flight-time (FP_FT) methods using a force plate and (b) the rise-time (VA_RT) and vertical distance (VA_VD) methods of the ankle using a high-speed video analysis. Additionally, the trial-to-trial reliability of each method was examined.
Eighteen participants (25.8 ± 5.9 years) performed three countermovement jumps. The jump height was determined by the six methods. One-way repeated measures ANOVA with post-hoc comparisons were used to evaluate systematic bias. Pearson correlation coefficients and typical errors between all the methods were calculated to determine random errors. Trial-to-trial reliability was assessed with intraclass correlation coefficients (ICC).
A systematic bias existed between the US (≤ 15.4 cm) as well as FP_DI (≤ 14.0 cm) and all the other methods (all P All methods showed a high trial-to-trial reliability, confirming their general usefulness. However, the systematic differences between the jump heights of the methods need to be considered. Consequently, regression equations allow the conversion of countermovement jump heights between the six methods with small typical errors of estimate.

Earthquakes are devastating natural disasters. When an earthquake occurs during a significant event, such as Asian football confederation (AFC) under-14 girls’ regional championship in Nepal (2015), all catastrophic casualties should be taken into account, including mental side effects on young sensitive groups. The present paper aimed to report risk-reduction activities for posttraumatic stress disorder (PTSD) in 18 young members of the Iranian football team.
Distant location of the team members persuaded the team physician to use Internet-based social applications for supportive psychotherapy during 1 year after the shock. The child report of posttraumatic symptoms (CROPS), along with the parent report of posttraumatic symptoms (PROPS), was used to collect data from players and their parents. No randomization (except for replications) was applied and no control group was recruited in this study.
The results showed that some of the girls had acute stress symptoms and were prone to acute stress disorder if left unattended. The average CROPS score was 20.06 (SD, 2.48) in the second week, which decreased to 1.33 (SD, 1.29) after 1 year. Similar results in the sixth and twelfth months showed that the girls could reach a stable mental status using online supportive psychotherapy.
Despite lack of access to patients, use of supportive psychotherapy is still possible. Online meetings can help psychologists follow the stages of treatment accurately. The results of CROPS showed that it is possible to provide psychotherapy support through online discussions with patients.

The tournament design of any FIFA World CupTM is characterized with a high amount of games within a short period of time with limited recovery periods. This study aimed to investigate alterations in match activity and fatigue patterns of players from top ranked teams during the 2014 FIFA World Cup in Brazil.
The performance data from the final four ranked teams were recorded from the official game statistics of the federation internationale de football association. Inclusion criteria were: a) played during the seven matches, and b) took part in at least 85% of the total playing time of its respective team.
Seventeen players fulfilled the criteria (eight defenders, five midfielders and four attackers). Average exposure of the selected players was 97.4% ± 4.1% (range 86% - 100%) of the tournament regular official playing time. Total distance covered was lower (P The analyses suggest that there wasn’t a general decline in player’s match activity during the 2014 FIFA World-cup in Brazil in a congested schedule.

Effects of lower-limb compression garments on hemodynamics during walking or running remain unclear.
The purpose was to examine the changes in tissue oxygen saturation (StO2) with well- and tight-fitted compression sleeves - before, during and after an exercise on treadmill.
14 athletes came to the laboratory three times to complete the same session with or without well- (COMP) and tight-fitted (COMP) calf compression sleeves. The session included an incremental exercise on treadmill: 2 min at each intensity - 1, 2, 3, 4, 5, 6 and 7 km/h - each was preceded and followed by a 10-minute rest in a seated position. Calf StO2 was recorded using near infrared spectroscopy before, during and after the exercise.
StO2 significantly increased with COMP and COMP before ( 25.2 ± 2.7 % and .5 ± 2.7 %) and after the exercise ( 11.0 ± 1.5 % and .2 ± 1.7 %). StO2 also increased while walking but declined as the intensity progressed ( 14.6 ± 1.9 %, .7 ± 1.7 %, .5 ± 1.8 %, .1 ± 1.8 %, 5.2 ± 1.7, .1 ± 2.0 % and -1.3 ± 4.0 % with COMP vs. .3 ± 2.0 %, .5 ± 1.7 %, .0 ± 1.9 %, .9 ± 1.7 %, 2.9 ± 1.6 %, -0.2 ± 2.2 % and -6.5 ± 3.6 % with COMP). With COMP the significance phased out earlier (2 km/h vs. 4 km/h with COMP) and was altered at 7 km/h (while the effects were trivial with COMP). The differential was considered small compared to without (Cohen’s d = - 0.38; 95 % CI -5.46 to 4.69) and COMP (d = 0.27; 95 % CI -5.30 to 5.84).
This study gives ground to the hypothesis that wearing calf compression sleeves may be useful during prolonged efforts involving sections of low-velocity walks (i.e.

This study aimed to compare exercise intensity through measuring oxygen consumption (VO2), heart rate (HR), and rating of perceived effort (RPE) during an underwater walking at a standardized gait velocity (step × min-1) when wearing swimsuit (SS) or aquatic pants (AP) that increased the drag force
20 young healthy participants (11 M, 9 F) were recruited; each participant was asked to perform two trials in a random order, one with SS, and the other with AP. Each trial consisted in a 20-minute walk on an underwater non-motorized treadmill at 60, 70, 80, and 90 step × min-1.
The total number of steps during the two trials and the walked distance was the same when wearing SS or AP at all rhythms. VO2, HR, and RPE were significantly higher with the use of AP at all gait velocities (P Owing to the larger drag force, AP can be considered as an effective device to increase exercise intensity since the cardiorespiratory response was greater when wearing AP rather than SS.

Many studies have shown that stress adversely effects cognitive function. However, the effect of acute mental stress is not well understood.
In this study, the effect of match-related stress on cognitive performance factors before and after matches has been studied among female futsal players of Pol-e Dokhtar, Lorestan province, in the west of Iran.
Futsal players’ perceptive and cognitive functions were studied using paced auditory serial test (PASAT) before and after each match. Ten female futsal players from Pol-e Dokhtar, Lorestan, with an average age of 20 ± 2 were tested using PASAT, 60 minutes before and after each match. Their cognitive function was measured using criteria, such as general mental health (GMH), sustained attention (SA), average response speed (ARS), and mental fatigue (MF). Moreover, the changes in salivary cortisol concentration were also measured.
The results indicated that in female futsal players, cortisol concentration in plasma was much higher before the match, compared with its concentration after the match. It should also be noted that general health, sustained attention, and response speed were higher after the match. On the other hand, their mental fatigue after the match was significantly lower than before the match.
It could be concluded that, before the match, stress level could highly effect individuals’ cognitive function. This impaired cognitive function seems to be due to severe mental stress, which in turn increases blood cortisol level.

Trainers provide nutritional information to their athletes, yet, their skills in this field remain weak. No related research has been conducted so far in the Middle East and North Africa (MENA) region.
In this cross-sectional study, 151 trainers working with adolescent athletes completed a validated psychometric questionnaire that identifies their practices of disseminating nutritional advice to athletes, their degree of nutritional knowledge, and the factors identifying their level of knowledge.
A considerable number of trainers gave advice to their athletes (82.8%). The trainers answered 51.1% of knowledge questions correctly. According to t-test results, the trainers, who provided nutrition advice scored 54.5%, significantly higher than trainers, who did not provide advice (47.7%; P = 0.002). A one-way Analysis of Variance (ANOVA) revealed a significant relationship between the score of the total knowledge of all trainers and qualifications (P = 0.001), own knowledge rating (P = 0.001), and nutrition training (P = 0.002).
These trainers were not ready to give advice to athletes and they should undergo additional nutrition training.

A professional football player sustains 2 injuries per season on average. Lower extremity injuries are the most common injuries among football players. To develop a prevention programs it is essential to recognize risk factors associated with the incidence of injuries. Previous studies focused on intrinsic risk factors of lower extremity. The association between spine abnormities and lower extremity injuries in professional athletes have only been scarcely studied.
The purpose of this study was to evaluate the effects of various spinal form abnormalities on the rate of lower extremity injuries in male professional football players.
This cohort study among Iranian Football players was implemented during the 2015 - 2016 season. All players were assessed for spinal alignment during Pre Participation Examinations. In total, club doctors documented information of 244 players out of 420 players.
There were 155 injuries recorded in total with at least one day absence from training or match, of which the most common injuries were hamstring muscle injuries (n = 41, 26%), ankle ligament injuries (n = 34, 22%) and adductor injuries (n = 25, 16%) respectively. Increasing thoracic kyphosis Cobb’s angle was associated with a reduction in the likelihood of exhibiting quadriceps injury, odds ratio (CI 95%): 0.806 (0.671 - 0.968).
The reason why players with lower thoracic kyphosis Cobb’s angle may be at risk for quadriceps injury is not clear. But biomechanical changes such as extensibility of hamstring and the balance between hamstring and quadriceps may partially explain the increased risk.

The aim of the present study was to examine the role of nationality on the pacing of Ironman triathlon (3.8 km swimming, 180 km cycling, and 42.195 km running). Data from 302,535 athletes (women, n = 61,087; men, n = 241,448) competing between 2002 and 2015 in 253 different Ironman triathlon races were analyzed. We examined split times (i.e. swimming, cycling, and running) and transition time, expressed as percentage of the overall race time. Participants were classified into performance groups according to their overall race time: 9 - 10 hours, 10 - 11 hours, 11 - 12 hours, 12 - 13 hours, 13 - 14 hours, 14 - 15 hours, 15 - 16 hours, > 16 hours. Compared to men, women spent relatively less time in swimming (P

Obesity, as a chronic disease, is becoming increasingly prevalent especially among women.
The purpose of this study was to evaluate and compare the effects of resistance training (RT), concurrent resistance training and aerobic training (RT AT) on visfatin concentrations and body composition in overweight and obese women.
An eight-week pretest-posttest design with two experimental exercising groups and one control group was used. 45 overweight and obese women were randomized into resistance training (RT), concurrent resistance and aerobic training (RT AT) or an education-only groups (EDU). All participants received a dietary and education/counselling intervention. However, only the RT and RT AT group participated in the eight-week exercise training.
Repeated measures analysis showed that visfatin was significantly decreased by 8.5% in the RT (P = 0.02) and 29.2% in the RT AT (P While RT and education-alone improved body composition and aerobic capacity, structured regular exercise incorporating both RT and AT may be required to improve visfatin and VO2max in overweight and obese females.

SCAT3 is a standardized tool, which can evaluate injured athletes for concussion and provide us with the necessary baseline data. Like any other sport, playing football (soccer) carries a high risk of injury. Thus, this study investigated the baseline properties of SCAT3 in Iranian Professional League football players and evaluated the correlation between different factors and a history of concussion.
All of the players of 16 different teams who would be participating in the 2016 - 2017 Iranian Professional League (n = 368), were enrolled in this study. Completing SCAT3 was part of the pre-competition Medical assessment. Beside presenting the descriptive data, different variables were analyzed to evaluate the association with a “prior history of concussion”, in order to find probable risk factors for head injuries.
Forty-one players have had a history of concussion in the previous year and data analysis among the different categories showed that having a history of concussion bore a significant correlation with number of symptoms and symptom severity (P values: 0.023 and 0.041, respectively).
Athletes with a history of concussion reported an increased number of symptoms and a higher severity score, but other SCAT3 properties such as total SAC scores and M-BESS were not affected by a history of concussion. This study aids clinicians in evaluating athletes suffering injuries to the head during football matches.

The aim of this study was to examine the incidence and patterns of primary exercise headache (PEH) in resistance trained male athletes. PEH is observed particularly during or after severe physical exercise and lasts up to 48 hours. While the focus of the literature has mainly been on the prevalence of PEH in the general population, few studies on athlete populations have been conducted so far. Therefore in a cohort study we examined the incidence and patterns of PEH in resistance trained athletes in an Iranian male sample.
A population of 116 resistance trained athletes, between 14 to 63 years old, was recruited. PEH was identified in the athletes according to a questionnaire based on the 3rd international classification of headache disorders. The athletes were followed up for six months on a monthly basis while the incidence, pattern and risk factors of PEH were evaluated in them in a precise manner.
The incidence of PEH in overall participants was evaluated 4.8 in 1000 hours exercise. The prevalence of headache during the follow-ups was 19.8% in which the highest headache incidence occurred in 20-30 years old athletes. PEH mainly occurred after sports and the quality of PEH was mainly a sudden (81%) pulsating (47%) headache which was felt mostly in the occipital region (39%). The incidence of PEH had a strong statistical correlation with having a history of PEH (odds: 3.8; 95% CI: 1.02 - 14.3).
Our study showed that incidence and prevalence of PEH in resistance trained athletes might be higher than general population. History of PEH was the main risk factor for developing PEH in resistance trained athletes.

In all age groups of handball players, anthropometric characteristics and physical capacities are important prerequisites to fulfilling the playing demands. However, there is no study that has compared anthropometric characteristics and physical capacities between junior and adult handball players by the same research design containing field tests.
This study aimed to investigate differences in anthropometric characteristics and physical capacities between junior and adult top-level handball players using various field tests. Relationships among physical capacities were also examined.
Ten male junior (18 ± 1 years) and eleven adult (26 ± 1 years) field handball players competing in the U19 Bundesliga and DKB Handball-Bundesliga, respectively, were tested for body height, mass, fat, and fat-free mass as well as 30 m speed and 22 m change of direction (COD), squat jump (SJ) and counter movement jump (CMJ), one repetition maximum (1RM) bench press, core strength-endurance, and interval shuttle run test (ISRT). Magnitude-based inferences, effect sizes (ES), and Pearson correlation coefficients (r) were computed for statistical analyses.
Juniors had a very likely lower body height, mass, and fat-free mass and likely lower 1RM bench press and ISRT performance (ES: 0.7 - 1.2). Contrary, juniors had a likely to very likely superior speed, COD, and SJ and most likely superior core strength-endurance performance (ES: 0.5 - 1.6). While speed, COD, and jump capacities were large to very large correlated in juniors (r = -0.55 - 0.86), they were mostly unclear correlated in adults (r = -0.05 - 0.79). Overall explained variance among speed, COD, and jump capacities was likely higher in juniors (51%) than adults (17%) (ES: 1.7).
This study shows that differences in anthropometric characteristics and physical capacities, and also in relationships among physical capacities, are evident between junior and adult top-level handball players, indicating different physical needs to play handball.