Use of an electronic goniometer during the performance of Bosco's Test [Utilizzo di un goniometro elettronico durante l'esecuzione del test di Bosco]

Bosco's test is a useful tool for evaluating the explosive and elastic power of the lower limbs of athletes. The widespread diffusion of this test has induced sport professionals to improve goniometers for the measurement of the knee angle during the jump. It is well established that the maximum height is reached when the jump is performed with the legs at an angle of 90°. In this study we compare the height obtained in the SJ and the CMJ carried out in the presence and in the absence of an electronic goniometer by 34 basketball players of different skill levels and ages. The goniometer was equipped with a visual and sound signal indicating to the athlete the flexion of the legs at 90°. We found that the height of the jump performed with the goniometer is always lower than that performed in its absence. The young athletes were much more influenced by the presence of the goniometer during the performance of the SJ compared to top level adult athletes. In the CMJ, the jump heights of the athletes with the goniometer is not significantly different from heights measured in its absence. We conclude that the use of the goniometer favours the reproducibility of the jump but also hampers the movements of the athlete particularly of the youngest ones. A very light instrument which does not inhibit the movement of the athletes is needed in order to improve the reproducibility of the test.