1Univerzitet u Ljubljani, Fakultet za sport, Slovenia
MODERN TAKE-OFF POWER DIAGNOSTICS
SAVREMENA DIJAGNOSTIKA ODRAZNE SNAGE
Sport Mont 2008, VI(15-16-17),
16-21
Take-off power is one of the main biomotor abilities for predicting the results of
many sport disciplines. It plays a particularly important role in motor situations when
the take-off power is combined with the velocity of movement. The core aim of this study
was to establish and analyse the fundamental kinematic, dynamic and electromyographic
parameters which generate the results of selected take-off power tests. The experimental procedure involved two elite female triple jumpers. According to Bosco’s protocol
the following tests were selected: squat jump, countermovement jump and drop jump
– 25 cm. The following were analysed: jump height, take-off time, flight time, take-off
velocity, maximum take-off force, angle velocity of the ankle, knee and hip joints, force
impulse and duration of the eccentric and concen ric phases of take-off. The 3D-kinematic
analysis of jumps was based on a system of nine SMART-e 600 video-cameras (BTS
Bioengineering), with a 60 Hz frequency and a 768 x 576 pixel resolution. The kinematic
parameters were processed using the BTS SMART Suite programme. Dynamic parameters
were established by means of two separate force-plat forms, namely Kistler, Type
9286A. The analysis of the electromyographic activity (EMG) of the following muscles:
m. erector spinae, m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus
lateralis, m. biceps femoris, m. tibialis anterior and m. gastrocnemius medialis was made
using a 16-channel electromyograph (BTS Pocket EMG, MYOLAB). The research
showed that the jump height (h) as a criterion of explosive power was generated by: the
velocity of take-off, flight time, force impulse in the concentric phase and optimal knee
joint angle. The analysis of the EMG activation in vertical jumps showed the proximaldistal principle of muscle activation. In the first phase of the take-off action, the trunk
extensors (m. erector spinae) and hip extensors (m. gluteus maximus) are activated. In
the second phase, the take-off efficacy is generated by the knee extensors (m. rectus femoris,
m. vastus medialis) and, in the final phase, the plantar flexors of the ankle joint (m.
gastrocnemius medialis) are activated. take-off power, diagnostics, dynamics, kinematics, EMG activation
Abstract
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