Dynamic Stability Assessment of the Lower Limbs of Karate Kyokushin Master Class Athletes

OBJECTIVES: The aim of the study was to determine the level of stability of the lower limbs in dynamic conditions in Karate Kyokushin master class athletes. We compared the results of the karate athletes with the control group. In the analysis, both the dominant (kicking) limb and non-dominant (supporting) one were taken into account. METHODS: The study involved 22 Karate Kyokushin master class athletes (13 men and 9 women aged 26.5 ± 3.9). This group consisted mainly of European Championships medalists in various weight categories. Their average training history was 14.6 ± 5.1 years. The control group consisted of 18 healthy, active volunteers (14 men and 4 women aged 21.4 ± 1.2). The measurements of dynamic stabilography were made with the Biodex Balance System (BBS) device. The dispersion of sway in the A/P (anterior/posterior) plane, M/L (medial/lateral) plane and overall stability indicator (OSI) were analyzed. The measurements were made with one leg position on the lower right and left limb successively and consisted of three 30-second repetitions at the second stiffness level of the stabilographic platform. For the purpose of further material development, persons declaring the right lower limb as the dominant one were selected in order to make the test and the control group more homogeneous. The results were analyzed statistically using the U-Mann-Whitney test assuming the significance threshold of p≤0.05. To assess the correlation, the Pearson's correlation coefficient was used. RESULTS: The analysis of the results showed a statistically significant difference in the overall stability indicator (OSI) of a non-dominant (supporting) limb between the test and the control groups. The abovementioned dependence concerning the overall indicator was affected mainly by stability parameters obtained in the A/P sagittal plane. A correlation between the training history and the overall stability indicator (OSI) in both limbs of karate athletes was also demonstrated. Namely, the increase in training experience of the athlete correlated with the increase in the stability level of both legs. Other results showed no statistically significant differences. CONCLUSION: 1. Kyokushin Karate master class athletes are characterized by lower level of stability of a non-dominant (supporting) lower limb in comparison with the control group. 2. The more training history experience the athlete has gained, the higher stability level in both lower limbs they have.