DESCRIPTIVE STUDY OF THE CONTRACTING PROPERTIES OF THE FLEXO-EXTENSION MUSCLES OF KNEE IN PROFESSIONAL AND AFFECTED FOOTBALL PLAYERS

Abstract

The purpose of this study was to compare the contractile properties of the flexo-extensor superficial musculature of the knee joint of both legs, in different categories of soccer players, in the muscles: rectus femoris (RF), vastus medial (VM), vastus lateralis (VM), biceps femoris (BF) and semitendinosus (ST). The sample are 38 players, 22 are professional players, (26.36 ± 4.68 years) and 16 are amateur players (21.06 ± 1.68). Measurements were made with tensiomyography (TMG-BMC Ltd., Slovenia), muscle displacement (Dm), contraction times (Tc), relaxation time (Tr) and contraction maintenance time (Ts). Student's t-test (p<0.05) was used for paired samples to compare the dominant leg with the non- dominant leg and to compare the measured variables between attackers and defenders. The muscles with the shortest contraction time in professional and amateur players are the VM (24,28 ± 2,75 ms y 23,01 ± 2,27, respectively) and the VL (24,07 ±3,88 ms y 21,36 ± 2,61, respectively) of both legs. The muscles with the longest contraction time (slowest) were the semitendinosus (ST) (48,1± 8,14 ms y 45,4 ± 6,4 ms respectively),, in professional and amateur players. The results show significant differences between professional and amateur players in all muscles, except the ST, in the variable related to fatigue Ts. It was also observed that the Dm is lower in defenders than in attackers in VL, VM and BF. No significant differences were observed between dominant and non- dominant leg. TMG has proven to be a useful tool for assessing the contractile properties of muscles in soccer players.