full text - Akademia Wychowania Fizycznego w Krakowie

The influence of plyometrics training on the maximal power of the lower limbs in basketball players aged 16–18
Time�[s]
5,2
5,1
5
4,9
4,8
4,7
4,6
1 2 3 4 5 6 7 8 9 10
Run�number
Fig. 2. Comparison of mean time in 30m run for the experimental (E) and control (K) group before (I) and after the experiment (II)
ties, both in left and right extremity (Table 4, 5). Identical
number of jumps performed by both lower extremities in
the proper phase of the experiment resulted in a greater
strength increase in the right knee fl exor. The strength
level of knee extensor increased as well, however not at
all tested velocities; no signifi cant difference was recorded
in the dynamic strength of the lower right extremity
(tested at 60º/s and 120º/s angular velocity) or left extremity
(tested at 60º/s angular velocity) (Table 6, 7).
Before the experiment, at 60º/s and 120º/s angular
velocity, the strength level of right knee extensor in basketball
players was on a similar level to the strength level
of left knee extensor; only the level of strength endurance
of left knee extensor was slightly higher than that of the
right knee extensor. It seems that the right lower extrem-
Table 3. Descriptive statistics and significance level of the differences in vertical jump [cm]
– 37 –
ity is more often used to perform the long step in layup
(opposing and take-off phase) while the left lower extremity
makes a short dynamic step (take-off phase). As
a result of the plyometric training there was a change in
strength endurance (tested at 240º/s angular velocity) of
knee extensors in both lower extremities. Changes in
dynamic strength levels were observed only in left lower
extremity at 120º/s angular velocity.
One may ask why before and after the experiment
there were no signifi cant differences in the level of dynamic
strength of right and left lower extremity extensors
(at 60º/s and 120º/s, and 60º/s angular velocity, respectively).
Perhaps motor activities in the regular basketball
training resulted in the development of high strength
level of knee extensors, and the experiment was not
Test N x ± S min – max S k K u T p
I 18 40,2 ± 4,86 30,9 – 52,1 0,494 1,050
II 18 40,0 ± 4,30 32,3 – 47,7 –0,350 –0,525
I 18 40,2 ± 4,86 30,9 – 52,1 0,494 1,050
III* 18 39,7 ± 4,44 32,4 – 47,4 –0,152 –1,122
II 18 40,0 ± 4,30 32,3 – 47,7 –0,350 –0,525
III* 18 39,7 ± 4,44 32,4 – 47,4 –0,152 –1,122
E �I
E �II
K�I
K�II
0,235 0,817
0,992 0,335
1,022 0,321
* Having observed no statistically significant changes in the level of explosive leg and trunk strength, the researchers decided to carry out test III believing
that a longer rest period will allow the subjects to show the real level of the tested ability.