Adolescent male soccer players have higher growth rates and risk of injury is associated with biological maturity.

BACKGROUND: The objective of this study was to ascertain disparities in growth and maturation between male adolescents engaged in soccer and their non-athletic counterparts, as well as to examine the injury features specific to young soccer players. METHODS: A total of 206 soccer players between the ages of 11-16 years, and 208 non-athletic peers were enrolled. Height, weight, body mass index (BMI), annual growth rate, and skeletal age evaluated using a left handwrist x-ray were determined. Biological and sexual maturation were evaluated using skinfold thickness, body composition, and Tanner stages. The game positions, initial age for playing soccer, the number of games per/ week, the number of sports injuries, date of injury, duration for return to activity, the site, nature, mechanism, and rate of injury were recorded for soccer players. Using an injury card, the characteristics of soccer player injuries were recorded. RESULTS: The mean age of the participants was 13.6 ± 1.5 years. There was no difference in the growth rates between the groups at the ages of 11.0, 12.0, and 15.0 but at the ages of 13.0 and 14.0 years growth rates were higher in the soccer group. The soccer players were taller than the controls. For all Tanner stages, soccer players had a lower BMI and total body fat percentage, as well as a faster growth rate. Injuries occurred at a rate of 39.3% per year among soccer players. The most common being toe injuries, and playing soccer increased the risk of multiple injuries. Additionally, injuries occurred more frequently in soccer players who were taller, heavier, with higher total body fat and/or higher growth rate, and most commonly occurred during Tanner stage 4. Futhermore, Tanner stage 4 had a higher incidence of two or more injuries than the other stages. CONCLUSIONS: Adolescent male soccer players have higher growth rates than their non-athletic peers, and their biological maturity status is associated with an increased risk of injury.

Joint position statement of the International Federation of Sports Medicine (FIMS) and European Federation of Sports Medicine Associations (EFSMA) on the IOC framework on fairness, inclusion and non-discrimination based on gender identity and sex variations.

The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no eligibility rules. Exclusion of all transgender or DSD athletes is contrary to the Olympic charter and unlawful in many countries. While having no gender eligibility rules, sport loses its meaning and near-universal support. Athletes should not be under pressure to undergo medical procedures or treatment to meet eligibility criteria. However, if an athlete is fully informed and consents, then it is their free choice to undergo carefully considered or necessary interventions for gender classification for sport to compete fairly and safely in their chosen gender. Free choice is a fundamental human right, but so is the right to fair and safe competition.

Ultrasonographic Evaluation of the Metacarpal Cartilage Thicknesses in Weightlifters and Volleyball Players.

OBJECTIVE: The aim of the study was to evaluate the possible effects of impact and loading on the metacarpal cartilage and hand functions in young elite athletes. DESIGN: In this cross-sectional study athletes with at least 3 yrs of sport background and who have been under a scheduled training program were enrolled. The second to fifth fingers' metacarpal head cartilage thicknesses were measured bilaterally by using ultrasonography. Handgrip and pinch strengths were measured. Michigan Hand Outcomes Questionnaire was also completed for every participant. RESULTS: A total of 42 male athletes (19 weightlifters, 23 volleyball players) and 46 healthy control subjects were enrolled. Metacarpal cartilage thicknesses of the athletes were thicker than those of the healthy controls (all P < 0.001). There were no differences between the dominant and nondominant hands (all P > 0.05). In the weightlifting group, Michigan Hand Outcomes Questionnaire work performance and pain scores were worse than the other groups (both P < 0.001). CONCLUSIONS: The presence of increased cartilage thickness measurements in the athletes suggests that sports activities might affect the metacarpal articular cartilage. Highest pain scores and lowest work performance scores in the weightlifters with highest metacarpal cartilage thickness might suggest that impact and loading during their sports play could lead to cartilage edema.

Psychiatric and functional evaluation of professional athletes following anterior cruciate ligament reconstruction.

OBJECTIVE: The aim of this study is to evaluate early phase depression and anxiety in the proffessional athletes who underwent anterior cruciate ligament (ACL) reconstruction and compare them with the functional improvement of knee. METHODS: Thirty-eight patients (35 males, 3 females; mean age±SD: 26.84±8.03) were included in this study. Measurements were obtained immediately following the operation and at Week 6 of postoperative rehabilitation. Depression and anxiety symptoms were evaluated by the Hospital Anxiety and Depression Scale (HADS), and knee function was evaluated by Lysholm Knee Scoring Scale (LKSS). RESULTS: Change in total LKSS scores from the time of admission (56.4±20.2) to the end of the sixth week (78.7±13.8) was significant (t=-8.21, p<0.001). Neither the HADS depression nor the HADS anxiety scores were above the cutoff values in the 2 assessments. Significant difference was noted in HADS anxiety scores between the time of admission (6.21±3.50) and at the sixth week (5.33±3.33) (t=2.02, p=0.05). However, HADS depression scores were not statistically different between the 2 evaluations (5.95±3.68 and 5.35±3.50 at admission and Week 6 week, respectively) (t=1.07, p=0.29). Changes between the 2 LKSS and HADS anxiety assessments were negatively correlated (r=-0.49, p=0.002), but there no correlation was detected between the total LKSS and HADS score changes. CONCLUSION: The decline of the signs of anxiety and depression at the sixth week of rehabilitation indicate that proper rehabilitation positively affects the emotional status of ACL reconstruction patients.

Glucosamine supplementation after anterior cruciate ligament reconstruction in athletes: a randomized placebo-controlled trial.

Although glucosamine is commonly consumed by athletes, its effectiveness in sports injuries is still under debate. We aimed to investigate the effects of glucosamine to the rehabilitation outcomes of anterior cruciate ligament (ACL) reconstructed athletes. Glucosamine-sulfate (1000 mg daily, for 8 weeks) was administered to half of the cohort of 30 male athletes, the other half used a placebo. Both groups received the same rehabilitation protocol. Knee pain and functions were evaluated by a visual analogue scale (VAS), International Knee Documentation Committee (IKDC) and Lysholm scores before and after oral administration. Additionally, an isokinetic test was performed after the administration period. The scores revealed significant improvements in both groups after 8 weeks, but no significant difference was detected between groups in any of the parameters. Glucosamine supplementation did not improve the rehabilitation outcomes of athletes after ACL reconstruction. This is the first study investigating this topic. Further studies will help to obtain clear evidence about glucosamine efficacy on ACL injured or ACL reconstructed athletes.

Periodontal nitric oxide pathway alteration due to precompetition anxiety in handball players.

BACKGROUND: Psychologic and physical stress is known to be related with periodontal disorders. The objective of this study is to investigate salivary and gingival crevicular fluid (GCF) nitric oxide (NO) metabolism and its association with the periodontal reaction to precompetition anxiety in competitive athletes. METHODS: A total of 18 elite male handball players participated in this study. The anxiety level of participants was determined by using a competitive state anxiety inventory-2 (CSAI-2). Periodontal clinical measurements, saliva, and GCF samples were obtained before the application of the CSAI-2 during the half-season break and just before the league championship match. NO-level, arginase, and NO synthase (NOS) activities were analyzed in saliva samples; NO and basic fibroblast growth factor (FGF-b) levels were analyzed in GCF samples. RESULTS: The CSAI-2 was significantly different between the two evaluation time points. GCF NO and FGF-b levels increased before the championship match, whereas saliva levels did not change. The plaque index and gingival index (GI) increased at the evaluation just before the championship match. The difference in the GI was statistically significant. CONCLUSION: The competitive stress of athletes may lead to a gingival/periodontal disturbance accompanied by an altered NO metabolism in saliva and GCF.

Proprioception and ankle injuries in soccer.

Because soccer attracts many participants and leads to a substantial number of injuries, especially of the lower extremities, it is important to study possibilities for injury prevention and proper rehabilitation to return safely to activities. Ankle sprains can be prevented by external ankle supports and proprioceptive-coordination training, especially in athletes with previous ankle sprains. Proprioception is a broad concept that includes balance and postural control with visual and vestibular contributions, joint kinesthesia, position sense, and muscle reaction time. Proprioceptive feedback is crucial in the conscious and unconscious awareness of a joint or limb in motion. Enhancement of functional joint stability by proprioceptive (or neuromuscular) training is important both in prevention and rehabilitation of athletic injuries.

Can heart rate values obtained from laboratory and field lactate tests be used interchangeably to prescribe exercise intensity for soccer players?

This study was undertaken to investigate the relationship between blood lactate concentration ([La]) and heart rate (HR) values obtained during treadmill and field tests at fixed velocities with respect to interchangeability of results to be used in exercise prescription. A total of 22 male soccer players participated in the study. Each player performed exercise tests on a motorized treadmill and in the field with 3-min runs and 30 s allowed for blood sampling. During both tests, velocities at the first, second, and third stages were 8, 10, and 12 km x hr(-1), respectively. Velocity was then increased by 1 km x hr(-1) every 3 min until exhaustion. During the field test, players ran on artificial turf on a 120-m hexagonal track marked with cones placed 20 m apart. Running velocity was controlled by means of audio signals. Blood samples were analyzed immediately with an automated lactate analyzer. HR was monitored continuously at 5-s intervals. Data were analyzed with Student's paired t tests to look for differences between treadmill and field data. Coefficients of variation and Blan-Altman plots assessed agreement of HR and blood [La] values between the 2 tests. Although running velocities corresponding to a fixed blood [La] of 4 mmol L-1 showed significant differences between treadmill and field tests (15.9+/-0.9 vs 14.1+/-0.7 km x h(-1), respectively) (P<.01), no significant difference between HR values was noted (190+/-7 vs 187+/-7, field vs laboratory, respectively). Overall, the mean intermeasurement coefficient of variation was 4.8% (+/-0.9%) for HR. Although the lowest coefficient of variation (2.4%) was found, fairly wide differences between individual field and laboratory HR values at velocities corresponding to fixed blood [La] of 4 mmol.L(-1) cast doubt on the interchangeability of tests.

Running velocities and heart rates at fixed blood lactate concentrations in young soccer players.

The purpose of this study was to examine the running velocities and heart rates at fixed lactate concentrations of young soccer players according to playing position and age. A total of 223 young male soccer players participated in this study. Each player performed incremental exercise tests on a treadmill. Running velocities and heart rates at 2 mmol/L-1, 2.5 mmol/L-1, 3 mmol/L-1, and 4 mmol/L-1 blood lactate concentrations were calculated with use of the spline function. Data were analyzed through analysis of variance to examine differences among various playing positions (ie, defenders, midfielders, and forwards) and 3 age groups (U17, under 17 y; U19, under 19 y; and U21, under 21 y). No significant differences were discerned between defenders, midfielders, and forwards in terms of running velocities and heart rates in accordance with specified lactate concentrations. Running velocities corresponding to all lactate concentrations showed no significant differences at all age groups, but heart rates in soccer players in the U21 and U19 age groups were significantly lower than in the U17 age group. Following a 3-y trial of 20 players, running velocities increased and heart rates decreased at all corresponding lactate concentrations. Results of this study suggest that (1) the endurance performance level of young soccer players is similar for all positions, and (2) heart rates are lowered with age and with training.

Effects of hypertonic dextrose on injured rat skeletal muscles.

OBJECTIVE: Histological examination of proliferative therapy effects on the healing process of muscular injury. METHODS: We performed this study between March and August 2002 at Ankara University, School of Medicine, Laboratory of Animal Experiments, Ankara, Turkey. We used an experimental animal model by conducting a standardized cut injury of the gastrocnemius muscle in 30 adult male albino rats, which we divided into 2 groups; proliferative therapy group and control group. We evaluated the injured rat muscles by light microscopy on the fifth, eight, and twelfth day of injury. RESULTS: The muscular regeneration process began at day 5 in both the control and proliferative therapy groups. The proliferative therapy group revealed a prominent inflammatory reaction, fibroblast migration, and necrosis with accompanying regeneration and excessive connective tissue formation. CONCLUSION: We cannot consider proliferative therapy an appropriate treatment modality for muscular injuries, unless there is evidence of normal muscle physiology and biomechanics post traumatically.

Effects of anterior tibial displacement on the proprioceptive functions of soccer players` knee joints.

OBJECTIVE: To investigate the effects of joint laxity on proprioceptive functions of the knee joints of soccer players. METHODS: In this study, we measured anterior tibial displacements and thresholds to detect the knee joint passive motion of 20 healthy soccer players (18.1+/-1.6 years of age). We performed all the measurements in Autumn 2000 in Ankara, Turkey. We applied the Mann-Whitney U test to analyze the relationship between the anterior tibial displacement and threshold to detect the passive motion (TDPM). RESULTS: There were no statistically significant differences between the TDPM values of the knee joints with insignificant laxity differences at different angles, and direction of motion (p>0.05). At 45 degrees of knee flexion and externally directed motion, we found the TDPM of looser knees to be significantly greater (p<0.05). CONCLUSION: Increased knee laxities without any clinical pathologic findings, have negative effects on knee joint proprioception. This is possibly due to the overuse degeneration of the anterior cruciate ligaments, which are the main stabilizers of knee joints.

Running velocities and heart rates at fixed blood lactate concentrations in elite soccer players.

This study was undertaken to examine the endurance performance of elite soccer players, according to age and playing position. A total of 197 male soccer players participated in this study. Each player performed exercise tests on the treadmill that included 3-minute runs and 30-second blood sampling intervals. During these tests, running speeds at the first and second stages were 10 km/hr -1 and 12 km/hr -1, respectively. When these tests were completed, running speed was increased by 1 km/hr every 3 minutes until the runner reached exhaustion. Blood samples were analyzed immediately by means of an automated lactate analyzer. Heart rate was monitored continuously at 5-second intervals. Running velocities and heart rates at 2-mmol/L -1, 2.5-mmol/L -1, 3-mmol/L -1, and 4-mmol/L -1 blood lactate concentrations were calculated with use of the spline function. Analysis of variance was used to analyze data to determine the differences between playing positions (goalkeepers, defenders, midfielders, and forwards) and age groups (older than 30 years of age, between 25 and 29 years old, between 20 and 24 years old, and 19 years old and younger). Statistical significance was set at P<.01. No significant differences were revealed between defenders, midfielders, and forwards regarding running velocities and heart rates and their correlation with specified lactate concentrations. Goalkeepers demonstrated lower endurance performance than players in the other playing positions (P<.001). Running velocities corresponding to all lactate concentrations showed no significant differences in all age groups, but heart rates in soccer players older than 30 years of age were significantly lower than those of players in other age groups (P<.01). Results of this study suggest that the endurance performance level of professional players is similar for players in all positions, except for goalkeepers, and that endurance performance is not adversely affected when a person's age increases beyond 30 years of age.

Energy expenditure of the paraplegic gait: comparison between different walking aids and normal subjects.

The aim of this study was to investigate the energy expenditure of walking with different aids in patients with spinal cord injury (SCI) and to compare the results with normal able-bodied control subjects. The tests were performed on a 20 m indoor path in a comprehensive rehabilitation clinic of a university hospital. Nine male patients with incomplete SCI at various levels from C6 to L2 and nine age- and gender-matched normal able-bodied subjects were enrolled in the study. Two different walking aids were evaluated: walker and crutch. The main outcome parameters--walking velocity, oxygen uptake and oxygen cost--were measured during ambulation with the two different walking aids. There was a statistically significant difference between controls and SCI patients in terms of walking velocity (P<0.001), and oxygen cost (crutches P<0.01; walker P<0.001). SCI patients walked more slowly and less efficiently. When we compared SCI patients' walking with the two different aids, a statistically significant difference was observed in velocity and oxygen cost (P<0.05) in favour of crutches. We concluded that energy expenditure studies are useful tools for giving objective measures to patients at the time of discharge and to encourage them to use efficient assistive devices in their daily activities.