SmarTracks Diagnostics v.3.16 Installation Guide & User Manual
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8.3.1.
Squat Jump (SJ)
The Squat Jump is a vertical jump used purely to test the concentric
strength in muscles used for jumping. This jump is performed from the
squat position without any countermovement. The upper body is bent
slightly forward, with the
knees bent to around 90°. The individual’s
hands are kept on their hips throughout the jump. This is to lessen the
effect of the arms, which could be used to boost height while jumping.
The exercise consists of jumping up as high as possible from the rest
position, without any countermovement when starting the jump. The
jump height is normally lower than the jump height for the Counter-
movement Jump.
Measuring parameters:
▪
Jump height [cm]
Test results
The test results are shown under the “Jumps” tab.
8.3.2.
Drop Jump (DJ)
The Drop Jump is a vertical jump for testing concentric strength
in muscles used for jumping, including reactive strength.
This jump is performed from a defined fall height. The individ-
ual’s hands are kept on their hips throughout the
jump. This is
to lessen the effect of the arms, which could be used to boost
height while jumping.
When executing the Drop Jump the athlete steps down and falls
from a box or platform. Upon landing, he immediately jumps up
as high as possible, keeping the ground time and horizontal
movement to a minimum.
Alongside the jump height, a brief contact time with the ground
is also measured. A reactive strength index (jump height divided
by contact time) can then be calculated. The impact velocity and
energy input into the muscles used for jumping are altered by