Relationship between the eco-intensity and the muscular thickness of the quadriceps with the power of vertical jump in school children: A pilot study.

Abstract

Objective: to correlate the echo-intensity, the muscular thickness of the rectus femoris (ERF) and the vast intermediate with the power of the vertical jump and the percentage of fast fibers in children of school age.

Method: 47 children between 6 and 10 years of age were evaluated. The echo-intensity and thickness of the anterior thigh (rectus femoris and vastus intermedius) was measured using a B-mode ultrasound. The power of the vertical jump and the percentage of fast fibers were measured by the vertical jump with counter-movement and repeat jumps for 15 seconds.

Results: The power of the vertical jump with counter-movement and the thickness of the vast intermediate longitudinal echo-intensity and transversal showed a moderate correlation (0.3644 and 0.3694, v.p. <0.05). The X² independence test (v.p. Fisher = 0.0236) shows association between the power of the vertical jump with counter-movement and the vast intermediate longitudinal echo-intensity and transversal. The percentage of fast fibers and the difference between the echo-intensity fat minus the echo-intensity of the rectus femoris added to echo-intensity of the vast intermediate indicate a moderate correlation (0.3555, v.p. 0.0142). The X² independence test (v.p. Fisher = 0.07003) shows no association between percentage of fast fibers and the difference between the echo-intensity fat minus the echo-intensity of the rectus femoris added to echo-intensity of the vast intermediate.

Conclusions: Ultrasound evaluation of the quadriceps muscle (specifically rectus femoris and vastus intermedius) can be a useful tool for evaluating anaerobic physical performance in healthy school children.