The purpose of the study was a biodynamic analysis of the kinematic, dynamic and EMG parameters of two types of
drop jumps (heights of 25 cm and 45 cm). The sample of measured subjects included four female elite triple jump athletes,
with their best results varying from 13.33 to 15.06 meters. The kinematic and dynamic parameters were calculated with
the use of a bipedal tensiometric force plate, which was synchronized with nine CCD cameras. A 16-channel electromyography
(BTS Pocket, Myolab) was used to analyze the EMG activation of the following muscles: m. erector spinae, m.
gluteus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. biceps femoris, m. soleus and m. gastrocnemius
medialis. In the drop jump from a 25 cm height, the measured subjects achieved the following results: height of jump
43.37±5.39 cm and ground reaction force 2770±411 N. In comparison, results for the drop jump from a 45 cm height were:
height of jump 45.22±4.65 cm and ground reaction force 2947±366 N. Vertical velocity of the take-off in the 25 cm drop
jump was 2.77±0.19 ms–1 and in the 45 cm drop jump it was 2.86±0.15 ms–1. Observation of the EMG activation revealed
the proximal to distal principle of muscle activation at work in both types of drop jumps. In the fi rst phase of the concentric
phase the most active muscles were m. gluteus maximus and m. rectus femoris. The greatest activity of m. gastrocnemius
medialis and m. soleus was noticed in the last third of the take-off action. Signifi cantly high EMG activation of m.
vastus medialis and m. vastus lateralis was already shown in the fl ight phase prior to the feet making contact with the
ground
