EN
The aim of the study was to identify the level of
isokinetic strength and power of lower limbs in 13-year-
old untrained boys (n=22, height: 158.5±8.0 cm, mass:
49.1±12.6 kg), to determine bilateral deficit between the
limbs in the tests and examine their mutual relationship.
Maximum peak muscle torque of knee extensors (PTQ)
and flexors (PTH) on dominant (DL) and non-dominant
leg (NL) were measured by isokinetic dynamometer. Three
types of a vertical jump: countermovement jump with
(CMJFA) and without arms (CMJ) and squat jump (SJ) were
performed on two force platforms. We found the significant effect (p<.01) of independent vari-
ables (knee extensors, flexors, AV) and their interaction
on PT. AV did not indicate any significant effect on bilat-
eral ratio of knee extensors (F4,84=.74, p>.05, ηp2=0.03),
however a significant effect of AV was found in knee
flexors (F4,84=2.70,p<.05, ηp2=.114). The type of jump had
no effect on the difference between force exerted by DL
and NL (F1,21=.102, p>.05, ηp2=.01). Bilateral deficit (Q:Q,
H:H) did not significantly correlate with bilateral deficit in
jumps (p>.05). Despite the possibility of identifying muscle asymmetries
in the sense of strength imbalances, their mutual relation-
ship with results in isokinetic dynamometry and power
jump tests is still unclear.