## 4 Discussion
[35] set a threshold of normal functional leg length discrepancy at 2 cm. The mean absolute asymmetry in our study was 0.9 cm, which is thus considered as normal leg length variation. Inter-limb asymmetries in vertical jumping parameters (4.77-11.12%) showed larger values compared to horizontal jumps (3.48-4.60%), which is in accordance with research conducted by [PERSON] et al. [15], who reported SLCMJ mean inter-limb asymmetries at 10.4 % and only 5.4% and 3.3% for horizontal jumps (SLHJ and SLLI). Similar results were reported by [PERSON] et al. [36] who found larger inter-limb asymmetries in SLCMJ (12.5%) compared to SLHJ (6.8%). Both of these studies were conducted on football players, which indicates that the variability between the testing methods might be substantially higher than the variability between the athletic populations. With that in mind, it can be suggested that vertical jumping is more sensitive for detecting asymmetries than horizontal jumping. While all of our maximal strength measures showed an excellent reliability (displayed in Table 1), the explosive strength (rate of torque development) were only moderately reliable. As the structured strength and conditioning training as well as the experience level contribute to reliability of data [37], our data can be interpreted with confidence. In the past years, there has been a lot of debate about defining normal asymmetry threshold, most common one being 10%, but different authors suggested values from 5% to 20% [6]. Taking all that into consideration, variability of asymmetry results in our data shows that asymmetry magnitude is dependent on the specific movement, test and parameter which indicates that a unifying asymmetry threshold cannot be established. Regression analysis revealed a relationship between asymmetries and performance: six variable model explained 49% of T-test performance variance. Independent variable Beta scores (0.27-0.58) show a small to medium individual relationship between different type of asymmetry and COD performance. Although several studies (including the present study) observed negative influence of asymmetries on COD performance, a number of studies identified contradicting evidence. [PERSON] et al. [10] showed negative influence (\(r\) = 0.638, 0.669, \(p\) < 0.01) of isokinetic concentric (60\({}^{\circ}\)/s, 180\({}^{\circ}\)/s, 240\({}^{\circ}\)/s) and eccentric (30\({}^{\circ}\)/s) knee strength asymmetries and COD performance (assessed with T-test). The study of [PERSON] et al. [11] reported similar results of association between knee strength asymmetries in slow (30\({}^{\circ}\)/s) and fast (300\({}^{\circ}\)/s) contractions and COD performance (T-test and 180\({}^{\circ}\) turn test). On the other hand, the relationship between COD performance (180\({}^{\circ}\) turn test) and strength asymmetries tested with the whole kinetic chain movements (e.g., IMTP) has not been detected [12; 13]. This observation could be explained by local strength asymmetries show higher magnitudes. Negative influence of asymmetry in vertical drop jump height and COD performance (180\({}^{\circ}\) turn test) (\(r\) = 0.66, \(p\) < 0.01 and 0.52, \(p\) < 0.05; depending on the side of the turn) was found by [PERSON] et al. [21]. Also, using horizontal jumps to assess asymmetries, [PERSON] et al. [38] found much lower correlations (\(r\) = 0.32 and 0.31, \(p\) <0.05) between asymmetry in horizontal jumping length (SLLI) and COD performance (V-cut and 180\({}^{\circ}\) turn test). Such a relationship was not found by [PERSON] et al. [15], who did not observe significant correlations between asymmetry in vertical (SLCMJ) height) and horizontal (SLH) and SLLI distance) jumping and COD performance (T-test and 180\({}^{\circ}\) turn test). Similarly, [PERSON] et al. [18] suggested that asymmetry in various parameters during single-leg squat jump and CMJ do not influence COD performance (zig-zag test). The study conducted by [PERSON] et al.