Jump percentile: a proposal for evaluation of high level sportsmen.

AIM: The goal of this study was to determine reference values of explosive strength for Spanish professional athletes using a force platform. Reference values are displayed as a sports-independent percentile distribution. METHODS: A total of 323 elite male athletes (age: 20.38 ± 4.65 years, body mass: 75.04 ± 14.30 kg, height: 178.62 ± 14.18 cm) from different disciplines performed the following test: squat jump (SJ), countermovement jump (CMJ), Abalakov test (AB), drop jump (DJ) and repeated jumps (RJ). We calculated: relative peak power, relative peak force, maximal height, symmetry index, explosive index of strength, relative effective impulse, duration of jump, elastic capacity, eccentric time, action of arm, jump number, average height, intensity and fatigue index of force. RESULTS: Significant differences were found among sports disciplines (P<0.05) in relative peak power, maximal height and relative effective impulse during the SJ, CMJ and AB tests. No significant differences were found among disciplines in DJ variables. In RJ, the main variable characterizing the disciplines analyzed was average height, which showed a significant negative association with athletics, soccer, volleyball and gymnastics. CONCLUSION: The results obtained suggest that a percentile table may be useful in assessing explosive strength in athletes, regardless of there being any reference values available for their sports discipline.

Time and frequency analysis of the static balance in young adults with Down syndrome.

The main objective of this study is to understand the differences in equilibrium control between normal subjects and those with Down syndrome. A total of 54 subjects participated voluntarily, divided into control group and Down syndrome group. The equilibrium of the subjects was tested under two conditions: bipedal support with eyes open and closed. The signals were analyzed in a time and frequency domain. The statistical parameters selected (i.e., RMS distance, mean velocity, mean frequency and sway area) to analyze the behavior of the center of pressures (CoP) are calculated employing the result of the combination of the time series data in both directions (i.e. resultant distance). In order to calculate the frequency bands produced by the displacements of the CoP, a Fast Fourier Transform of the data was performed. The group with Down syndrome showed poorer static equilibrium control than the control group in the time domain. In the frequency domain, we found differences between the groups in the distribution of energy in the frequency bands analyzed. In addition, we observed the existence of an interaction effect of the group and the condition tested (p<0.001). These findings show that in the absence of visual information, the control group increases the energy at low frequencies, while the group with Down syndrome decreases it. Additionally, the lower amount of energy observed in this band under the 'eyes closed' condition may serve to identify abnormalities in the functioning of the vestibular apparatus of individuals with Down syndrome and/or difficulties experienced by these individuals in extracting relevant information from this route.

Use of beta2 agonists in sport: are the present criteria right?

BACKGROUND: The regulations for doping control prohibit the use of beta2 agonist bronchodilators (salbutamol, salmeterol, formoterol, and terbutaline) unless the subject follows the procedure known as abbreviated therapeutic use exemption (ATUE). OBJECTIVE: To highlight how the interest in discovering possible cheats may result in damage to athletes who really need bronchodilator treatment. METHODS: Thirty one high level athletes (18 men and 13 women) with a previous diagnosis of asthma were examined in our laboratory in order to obtain an ATUE for beta2 agonists. All the subjects underwent spirometry at rest. If the results were normal, the subjects underwent an effort test and, if negative, a methacholine test inhaling progressive doses of methacholine until a fall of 20% in forced expiratory volume in one second (FEV1) was achieved. The international anti-doping regulations require that the fall in FEV1 occurs with a concentration of methacholine (PC20) lower than 2 mg/ml (4 mg/ml for Torino 2006). In clinical practice, a test is positive if the response occurs with a PC20 lower than 8 mg/ml. RESULTS: Only one subject met the criterion for the bronchodilation test at rest. The remaining 30 athletes underwent an effort test, which was positive in nine of them. In 21 cases (13 men and 8 women) the effort test was negative so a methacholine test was carried out. Seven (33%) were negative for ATUE with a PC20 higher than 8 mg/ml, seven (33%) were positive for ATUE with a PC20 less than 2 mg/ml, in four (19%) the PC20 was 2-4 mg/ml, and in three (14%) it was 4-8 mg/ml. CONCLUSIONS: Strict vigilance of fair play should be pursued, but excessive control can lead to situations of inequality for asthmatic athletes such that a third of athletes cannot be treated with beta2 agonists. Therefore under current regulations, asthmatic athletes are often denied the most effective therapeutic option.