Validade de um procedimento utilizando câmeras digitais de baixo custo para realização dos testes de velocidade de corrida em 30 metros e do salto com contra movimento

Abstract

This present study is aimed to examine the concurrent validity of the height of counter movement jump (SCM), and the time of the 30 meters speed test in straight line (V30), comparing low-cost equipment, digital cameras 30Hz (NIKON COOLPIX S3400) and high speed camera 240 Hz (casio EXILIM ZR200), with the equipment most commonly used in studies: contact mat and photocells. 24 volunteers nonathletes from both sexes with 22,5 (± 4,5) age average participated. Each one performed three trials of each test with one minute to rest between each attempt and three minutes to rest between each test. The subjects had no medical impediment to the achievement of the tests, according to information provided by them. The heights (cm) averages in SCM the measures in the contact mat were 36.74 ± 7.03, with the 30 Hz camera they were 39.52 ± 7.44 and with the 240 Hz camera were 35.42 ± 7.09. In the V30 time found in the average distances of 10 meters by photocells were 1.6083 ± 3.7093, with the 30 Hz camera were 1.5958 ± 3.4908 and with the 240 Hz camera were 1.5688 ± 3.8283. The analyses of the videos were made by the software Free Kinovea 0.8.15. ANOVA was performed with repeated measures to identify differences between tests averages. In SCM was noted a significant difference of digital cameras as opposed to the contact mat, in the V30, with only the 240Hz camera the average run time was significantly different relative to photocell (P<0.0001). The linear regression in the SCM and in the V30 showed representative values regarding the correlation coefficient (SCM: 30 Hz; r2= 0,862, 240 Hz r2= 0,987; V30: 30 Hz r2= 0,981; 240 Hz r2= 0,959; p<0,001). The Bland-Altman plotting showed that the camera 240 Hz is more precise to the SCM while the camera 30 Hz is more effective to measure the times in the V30. However, all the equipment shown to be valid to measure flight height in the SCM and times in the V30.