The Development Of Jumping Equipment Fo Rlong Jump Specific Strength Training And Its Biomechanical Estimation

Introduction
The purposes of this research were to design and develop a set of speeds-control jumping equipment that could intensify
specific ability of long jumpers’ take-off leg, and used it to test the take-off, so as to make a preliminary biomechanics
assessment of dynamic adaptability in long jump training.

Methods
Nine male long jumpers were required to perform take-off in the equipment; the speeds-control in the experiment were
6m.s-1, 7m.s-1, 8m.s-1, and 9m.s-1 respectively. As well as all subjects were required to complete running long jump takeoff.
All kinematics and dynamics data were gained by high two high-speed video cameras (JVC9800, 100Hz, 200Hz), a
force platform (500Hz, Kistler 9281B) and an accelerometer (1000Hz) synchronized measuring and analyzed. The
‘inverse dynamics’ method [1] was used to calculate the muscles moment of hip, knee and ankle of the take-off leg.

Results
The figure 1 (a, b, c) showed the average results of all subjects’ joint moment of hip, knee and ankle in different speedscontrol
testing (SCT), and figure 2 (a, b, c) were their comparisons between SCT (9m.s-1) and long jump, respectively.
Joint moment=Moment/BW (N.m/kg), Time=Normalized time (%). Positive=extend, Negative=flex.

Discussion / Conclusions
The results of different speed-control testing in the equipment well reflected the muscles’ active characteristic of hip,
knee and ankle. It was accordance with long jump. In SCT, with the controlling speed increasing (6 m.s-1-9 m.s-1), the
muscles contraction ability enhanced. All joints (Hip, Knee and ankle) chiefly presented extensors moment in take-off,
especially, in earlier phase of take-off (within 30%). The ability of fast eccentric, concentric contraction and the switch
velocity from eccentric to concentric were important to take-off. In running long jump, the larger peak of knee flexion
moment emerged in earlier take-off phase (within 8%), which indicated the knee flexion muscles actively contracted in
this period. It must draw coaches’ and athletes’ attention in training.

References
[1] Winter D. (1979). Biomechanics of Human Movement. John Wiley & Sons Press.

NOTA: O texto com a iconografia está no anexo

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