Relative age-related differences between different competitive levels and field positions in young soccer players.

The aims of this study were to report the relative age effect in different competitive levels and field positions and to analyse the differences within and between different competitive levels and field positions. Data for 203 young soccer players (14.2 ± 1.1 years) included anthropometrics and physical performance (Countermovement jump [CMJ], 30-m sprint, T-test and Yo-Yo IR1). Their competitive level and their field position were registered. The percentage of relative older players (1stHY) was higher in the better competitive levels (L1: 80.6%, p <.001; L2: 68.2%, p <.001 and L3: 58.5%, p <.01), but it was similar between field positions (DF: 68.1%, p <.001; MF: 69.6%, p <.001 and FW: 67.2%, p <.001). Anthropometrical and physical performance differences were found between players of different competitive levels but not between relative older and younger players in each competitive level and field position. The relative age effect is higher in the better competitive levels. Anthropometrical and physical performance differences between players are not due to the relative age but to the level of competition. Relatively older players do not seem to be more likely to be selected for specific field positions. The causes of relative age effect need more research.

The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training.

BACKGROUND: It has been suggested that strength training effects (i.e. neural or structural) vary, depending on the total repetitions performed and velocity loss in each training set. PURPOSE: The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training). METHODS: Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]). The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM]) and repetitions at maximum power (4 to 9 repetitions, or 'reps'). Volume (sets x repetitions) was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%-66.6% of 1RM). The training programme ran over 11 weeks (2 sessions per week; 4-5 sets per session; 3-minute rests between sets), with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO) with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST) and cortisol (SC) concentrations. Rate of perceived exertion (RPE) and power output were recorded in all sessions. RESULTS: Following the intermediate test, PPO was increased in the OP group for each load (10.9%-13.2%). Following the post-test, both experimental groups had increased 1RM (11.8%-13.8%) and PPO for each load (14.1%-19.6%). Significant decreases in PPO were found for the TT group during all sets (4.9%-15.4%), along with significantly higher RPE (37%). CONCLUSION: OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE.

Short-term effect of crunch exercise frequency on abdominal muscle endurance.

Despite core exercise programs are broadly used to increase muscle function and to promote low back health, there is a lack of scientific evidence on some of the most important characteristics of trunk exercise programs, as for example training frequency. This study aimed to compare the short-term effect of training frequencies of 1, 2 and 3 days per week (d/wk) on abdominal muscle endurance in untrained adolescents. One hundred and eighteen high-school students (59 men and 59 women) with no previous experience in structured abdominal exercise programs were assigned randomly to groups that trained 1 d/wk (G1; N.=21), 2 d/wk (G2; N.=27), 3 d/wk (G3; N.=23), or to a control group (CG; N.=47) that did not train. The training groups performed crunch and cross-crunch exercises 1, 2 or 3 d/wk during six weeks. Before and after the training period, the bench trunk-curl test (BTC test) was carried out to assess abdominal muscle endurance. Men obtained higher BTC test scores than women before and after training. Training frequencies of 1, 2 and 3 d/wk provided a significant increase in BTC test scores; however, no significant differences between the three groups' scores were found after training. Therefore, a small dose of crunch exercise training (1 d/wk) may be sufficient stimulus to increase abdominal endurance in untrained male and female adolescents, at least during the first weeks of an abdominal exercise program, which seems a very relevant finding in terms of time-cost efficiency.

Schwannomas múltiples de nervio mediano: descripción de un caso / Multiple median nerve schwannoma: a case report

Introducción: el abultamiento y las parestesias que originan los schwannomas múltiplessuelen confundirse con otras enfermedades más frecuentes en la mano: lipoma, ganglión,síndrome de túnel carpiano.Caso clínico: presentamos un caso poco frecuente de schwannomas múltiples del nerviomediano en un varón de 20 años. Este tipo de tumores no se manifi esta con défi cit neurológicosimportantes.Conclusiones: la resonancia magnética es muy útil en el diagnóstico preoperatorio y en laplanifi cación de la cirugía. La disección intracapsular microquirúrgica fue realizada deforma satisfactoria, y en la actualidad no hay recidiva del tumor(AU)

Introduction: The bulging masses and paresthesias caused by multiple schwannomas areoften confused with the symptoms of other more common pathologies of the hand:lipoma, ganglion, carpal tunnel syndrome.Clinical case: We present a rare case of multiple median nerve schwannomas in a 20-year-old male. These tumors are not accompanies by signifi cant neurologicalimpairment.Conclusions: Magnetic resonance imaging (MRi) is very useful in preoperative diagnosisand surgical planning. Microsurgical intracapsular dissection was performed satisfactorilyand the tumor has so far not recurred(AU)

Risk factors and predictive models of giant cell arteritis in polymyalgia rheumatica.

OBJECTIVE: To identify in polymyalgia rheumatica the best set of predictors for a positive temporal artery biopsy and to define predictive models with either a high or low probability of giant cell arteritis (GCA). PATIENTS AND METHODS: Retrospective study of 227 patients, 137 with polymyalgia rheumatica unassociated with arteritis (group A) and 90 with polymyalgia associated with biopsy-proven giant cell arteritis (group B or training set). Data on demographic features, clinical and laboratory abnormalities were collected. Risk factors for arteritis were estimated by nonlinear logistic regressions. Simple predictive models were constructed with those predictors more related to arteritis by multivariable analysis. These models were then tested in group B and in 89 cases of arteritis without polymyalgia rheumatica (group C or test set). RESULTS: The best predictors of arteritis were a new headache odds ratio (OR) 13.6 (95% confidence interval [CI] 4.7 to 39.3); age at onset < 70 years OR 0.11 (CI 0.04 to 0.35); abnormal temporal arteries OR 4.2 (CI 1.3 to 13.7); raised liver enzymes OR 2.9 (CI 1.1 to 7.8), and jaw claudication OR 4.8 (CI 1.0 to 22.7). Amaurosis was only observed in patients with arteritis. Three subsets had a very high risk of arteritis: (1) Patients with recent headache, abnormal arteries, and > or = 70 years at disease onset: sensitivity 44%, positive predictive value (PPV) 93%, likelihood ratio (LR) 20.3; (2) patients with a new headache, jaw claudication, and abnormal arteries: sensitivity 34.4%, PPV 96.9%, LR 47.2; and (3) those, that in addition to the last 3 features, were > or = 70 years of age at disease onset: sensitivity 26.7%, PPV 100%. We could also identify a subset with a very low risk of arteritis constituted by patients < 70 years, without headache, and with clinically normal temporal arteries: sensitivity 1.1%, PPV 1.7%, LR 0.03. In group C or the test set, these four predictive models correctly identified 57.3%, 29.2%, 23.6, and 3.4% of patients, respectively. CONCLUSIONS: In polymyalgia rheumatica it is feasible to identify subsets with a very high likelihood of GCA. Although in some of these subsets the diagnosis of arteritis is almost certain, we suggest that even then it should be confirmed by temporal artery biopsy. By contrast, in those patients with polymyalgia < 70 years and without cranial features of giant cell arteritis, the risk of vasculitis is so low that the biopsy could be initially avoided and the patient treated with low-dose corticosteroids.

Extreme Value Analysis of Wave Heights.

This paper discusses the most common problems associated with the determination of design wave heights. It analyzes two common methods used in fitting wave data and shows some of the stability or inconsistency problems associated with commonly used distributions. Some methods to obtain confidence intervals, detecting of outliers and treatment of missing data are given.