The Influence of Kyokushin Karate Training on the Lower Limb Muscle Groups Strength Symmetry as a Factor of Contactless Injuries

Introduction. Kyokushin karate is a full-contact style of karate. In addition to typical injuries resulting from opponent strikes during fights, non-contact injuries of the lower limbs also occur. The most common of these include injuries to the upper ankle joint and the knee. One of the causes of such injuries is the performance of motor tasks in an asymmetrical manner, with a clear preference for the dominant side of the body. Based on these observations, the aim of the study was to examine the relationship between asymmetries in strength and power and the occurrence of non-contact lower limb injuries. Material and Methods. The study involved 28 participants (4 females and 24 males) aged 23.39 ± 3.89 years, including 15 (2 females and 13 males) practicing Kyokushin karate and 13 (2 females and 11 males) with no experience in combat sports. None of the participants had a history of hip, knee, or upper ankle joint injuries. Passive and active range of motion measurements were conducted for the hip, knee, and upper ankle joints. Isometric strength testing was performed for the flexors and extensors of the knee and upper ankle joints. Reactive strength index (RSI) was assessed using a force plate. Results. Kyokushin karate practitioners exhibited high symmetry in the assessed strength and power parameters. In the control group, knee flexor strength significantly differed between the dominant and non-dominant limbs (p = 0.029). Additionally, karate practitioners demonstrated significantly higher RSI values compared to the control group (p = 0.048). Conclusions. Kyokushin karate training contributes to symmetrical development of lower limb strength and power. The observed symmetry in these parameters cannot be considered a direct cause of non-contact lower limb injuries in this population.