ABSTRACT The main objective of the present study was to analyze the performance of the jump and landing technique in adolescent team sports athletes through the modified version of the Tuck Jump Assessment, (TJA). As a secondary objective, the results obtained were compared, according to sex. Each outcome measure of the tool was scored through video analysis of the test of the 75 participants included in the study. The main outcome measures were the total score of TJA and each of the ten items: Knee valgus at landing (1), thighs do not reach parallel (2), thighs not equal side-to-side (3), foot placement not shoulder width apart (4), foot placement not parallel (5), foot contact timing not equal (6), excessive landing contact noise (7), pause between jumps (8), technique declines prior to ten seconds (9), and does not land in same footprint (10). The variables contemplated were the global score of the TJA and the ten criteria of the instrument. The average values of the global score of the modified version of the TJA were 8.85±2.31 in the total sample (8.85±2.63 men vs. 8.86±2.14 women). The results of the gender comparison indicated significant differences in item 1(χ2=10.288; p< 0.01), item 2 (χ2=20.788; p<0.01), item 4 (χ2=22.587; p<0.01) and item 10 (χ2=8.883; p< 0.01). Consequently, the analysis of the jump and landing pattern makes it possible to identify neuromuscular and biomechanical alterations of the jump-landing pattern.

RESUMO O objetivo principal do presente estúdio fue analisar o rendimiento da técnica do salto e aterrissagem em deportistas adolescentes mediante a versão modificada do Tuck Jump Assessment (TJA). Como objetivo secundário se comparar os resultados obtidos, según sexo. Se puntuó cada variável do herramienta mediante a análise no vídeo da prueba dos 75 participantes incluidos no estudio. As variáveis contempladas na versão global do TJA e cada critério do instrumento: 1) Valgo de la extremidad inferior en el aterrizaje; 2) Muslos no paralelos (ponto máximo de salto); 3) Muslos no alineados durante la fase de vuelo; 4) Mala alineación de los pies con los hombros; 5) Posición de los pies no paralela (de la punta al talón); 6) Contacto desigual de los pies (aterrizaje asimétrico); 7) Demasiado ruido en el aterrizaje; 8) Pausa entre saltos; 9) La técnica empeora antes de los 10 segundos; 10) No aterriza en el mismo punto (salto consistente). Os valores prometidos da versão global modificada do TJA fueron 8.85 ± 2.31 no total da muestra (8.85 ± 2.63 hombres vs. 8.86 ± 2.14 mujeres). Os resultados da comparação segundo sexo indicaron diferencias relevantes no critério 1 (χ2 = 10.288; p <0.01), no critério 2 (χ2 = 20.788; p <0.01), no critério 4 (χ2 = 22.587 ; p <0.01) e o critério 10 (χ2 = 8.883; p <0.01). Na sequência, a análise do patrón de salto y aterrizaje permite identificar alterações neuromusculares y biomecánicas del patrón de salto-aterrizaje.

RESUMEN El objetivo principal del presente estudio fue analizar el rendimiento de la técnica del salto y aterrizaje en deportistas adolescentes mediante la versión modificada del Tuck Jump Assessment (TJA). Como objetivo secundario se compararon los resultados obtenidos, según sexo. Se puntuó cada variable de la herramienta mediante el análisis en video de la prueba de los 75 participantes incluidos en el estudio. Las variables contempladas fueron la puntuación global del TJA y cada criterio del instrumento: 1) Valgo de la extremidad inferior en el aterrizaje; 2) Muslos no paralelos (punto máximo de salto); 3) Muslos no alineados durante la fase de vuelo; 4) Mala alineación de los pies con los hombros; 5) Posición de los pies no paralela (de la punta al talón); 6) Contacto desigual de los pies (aterrizaje asimétrico); 7) Demasiado ruido en el aterrizaje; 8) Pausa entre saltos; 9) La técnica empeora antes de los 10 segundos; 10) No aterriza en el mismo punto (salto consistente). Los valores promedios de la puntuación global de la versión modificada del TJA fueron 8.85±2.31 en el total de la muestra (8.85±2.63 hombres vs. 8.86±2.14 mujeres). Los resultados de la comparación según sexo indicaron diferencias significativas en el criterio 1 (χ2=10.288; p< 0.01), en el criterio 2 (χ2=20.788; p< 0.01), en el criterio 4 (χ2=22.587; p< 0.01) y en el criterio 10 (χ2=8.883; p< 0.01). En consecuencia, el análisis del patrón de salto y aterrizaje permite identificar alteraciones neuromusculares y biomecánicas del patrón de salto-aterrizaje.

Multi-center epidemiological studies must ascertain that their measurements are accurate and reliable. For laboratory measurements, reliability can be assessed through investigation of reproducibility of measurements in the same individual. In this paper, we present results from the quality control analysis of the baseline laboratory measurements from the ELSA-Brasil study. The study enrolled 15,105 civil servants at 6 research centers in 3 regions of Brazil between 2008–2010, with multiple biochemical analytes being measured at a central laboratory. Quality control was ascertained through standard laboratory evaluation of intra- and inter-assay variability and test-retest analysis in a subset of randomly chosen participants. An additional sample of urine or blood was collected from these participants, and these samples were handled in the same manner as the original ones, locally and at the central laboratory. Reliability was assessed with the intraclass correlation coefficient (ICC), estimated through a random effects model. Coefficients of variation (CV) and Bland-Altman plots were additionally used to assess measurement variability. Laboratory intra and inter-assay CVs varied from 0.86% to 7.77%. From test-retest analyses, the ICCs were high for the majority of the analytes. Notably lower ICCs were observed for serum sodium (ICC=0.50; 95%CI=0.31–0.65) and serum potassium (ICC=0.73; 95%CI=0.60–0.83), due to the small biological range of these analytes. The CVs ranged from 1 to 14%. The Bland-Altman plots confirmed these results. The quality control analyses showed that the collection, processing and measurement protocols utilized in the ELSA-Brasil produced reliable biochemical measurements.

To efficiently examine the association of glutamic acid decarboxylase antibody (GADA) positivity with the onset and progression of diabetes in middle-aged adults, we performed a case-cohort study representing the ~9-year experience of 10,275 Atherosclerosis Risk in Communities Study participants, initially aged 45-64 years. Antibodies to glutamic acid decarboxylase (GAD65) were measured by radioimmunoassay in 580 incident diabetes cases and 544 non-cases. The overall weighted prevalence of GADA positivity (³1 U/mL) was 7.3%. Baseline risk factors, with the exception of smoking and interleukin-6 (P £ 0.02), were generally similar between GADA-positive and -negative individuals. GADA positivity did not predict incident diabetes in multiply adjusted (HR = 1.04; 95%CI = 0.55, 1.96) proportional hazard analyses. However, a small non-significant adjusted risk (HR = 1.29; 95%CI = 0.58, 2.88) was seen for those in the highest tertile (³2.38 U/mL) of positivity. GADA-positive and GADA-negative non-diabetic individuals had similar risk profiles for diabetes, with central obesity and elevated inflammation markers, aside from glucose, being the main predictors. Among diabetes cases at study's end, progression to insulin treatment increased monotonically as a function of baseline GADA level. Overall, being GADA positive increased risk of progression to insulin use almost 10 times (HR = 9.9; 95%CI = 3.4, 28.5). In conclusion, in initially non-diabetic middle-aged adults, GADA positivity did not increase diabetes risk, and the overall baseline profile of risk factors was similar for positive and negative individuals. Among middle-aged adults, with the possible exception of those with the highest GADA levels, autoimmune pathophysiology reflected by GADA may become clinically relevant only after diabetes onset.