Isokinetic Strength And Strength Asymmetries In Relation To Laterality And Muscle Group In Soccer Players
Abstract
To determine the MS and SA at different velocities depending in laterality and muscle group in elite young soccer players. METHODS: Sixty one soccer players of the U16 highest Czech youth league (age 15.7+-0.3 years) were assessed on Cybex Humac Norm isokinetic dynamometer.
Following parameters were obtained during five (60,120,180,240,300 o.s-1) angular velocities (AV) for dominant (DL) and non-dominant leg (NL): Peak torque (PT), knee extensors (KE) ratio (Q:Q) and knee flexors (KF) ratio (H:H), ipsilateral ratio between H and Q for both legs (H:Q). Mixed model MANOVA and post hoc Bonferroni test were used for statistical assessment.
RESULTS: The level of PT at the velocity of 60o.s-1 was as follows: KEDL: 3.03+-0.34 N.m.kg-2, KENL: 3.03+-0.34 N.m.kg-2, resp. KFDL: 1.79+-0.26 N.m.kg-2, KFNL: 1.69+-0.24 N.m.kg-2.
AV and muscle group (MG) had a significant effect on PT in the players (PT: F4,960=2468.69; p0.05; η2=0.01, KF: F1,120=1.330; p>0.05; η2=0.01). AV did not have any significant effect on the bilateral ratio between the legs (F4,480=604; p>0.05; η2=0.01).
KF showed significantly higher values of the bilateral ratio in comparison to the KE (F1,120 = 21.05; p<0.01; η2=0.15). The H:Q ratio in the NL was significantly compare to DL (F1,120=18.03; p<0.05; η2=0.09).
CONCLUSION: The KFs demonstrated a higher degree of the bilateral ratio in comparison to KEs. Forty two 42 players (68.9 %) had muscle imbalance in KEs or KFs between the extremities at least at one velocity.
Monitoring of MS indicators enables identification of possible MS imbalances. Screening examination of MS imbalances may be thus a useful tool for prevention of muscle injuries in soccer players.