# Defining the Influence of Fatigue Protocol on Kinematic Parameters of Ippon Seoi Nage
## 4 Discussion

Table 3: Results ofANOVA for repeated measures between the observed groups before and after the fatigue protocol. parameters are significantly affected in the simulation of situational conditions. Since, as with most previous studies [9; 14; 20; 21; 22; 23], the throw was performed without the resistance of the uke, it can be assumed that with his resistance, it would be even more difficult to maintain the observed parameters at an optimal level. A judo fight in senior and junior competition lasts four minutes, during which both fighters are significantly exhausted. A fighter who, despite being exhausted, manages to perform throwing techniques at a technically higher level will certainly have a lower expenditure of energy and, at the same time, be at an advantage over his opponent. A drop in skill level leads to a whole series of difficulties in the kinematic chain responsible for throwing. The authors of [33] proved that fatigue due to a competitive judo fight affects the kimono grip strength in the right and left hand, as well as during simulated judo fights, i.e., during training. Since it is important not to lose control over the uke's kimono grip throughout all three phases of performing the ISN throwing technique, it is important to understand the connection between fatigue, a drop in the level of ability, and the disruption of kinematic parameters in the performance of throwing. Furthermore, poor execution of the throw under the situational conditions can lead to injury. According to previous research [34], in top-level judokas, the highest number of injuries occur in a standing position during the competition (78.0%), of which 22.3% are inflicted on the tori during throw performance. In the ISN throw, the majority of injuries relate to lower body extremities [35]. We state that highly trained judoka able to conduct the technically correct performance of the ISN have reduced risk of injury. Regarding muscle injury during competition, recent findings have shown that (MMA) fighters already present tissue injury and initiated inflammatory processes at the end of a competition [36; 37]. Therefore, complex (metabolic) fatigue, such as complicated physiological status, during competition could also affect the mechanics required for the perfect application of the ISN throw in judo matches. Kinematic parameters should not be viewed in isolation, but as an interconnected kinematic chain that leads to a successful throw. Disturbance or poorer performance in one part entails the need for compensatory actions in another part of the kinematic chain, and with it the overall reduced efficiency of the throw itself. The variable L_shou_A indicates the angle of the shoulder that occurs in the kuzushi phase, and is important because it disrupts the opponent's balance. A larger angle of the shoulder means a stronger action of the tori's left hand and, at the same time, raising the uke's COM to a higher level, which will enable the tori to be placed in a better position in the tsukuri phase. In this case, the values of the observed variables R_shou_a and Pel_tsu_H will be higher. This indicates the tori's lower position in the tsukuri phase and points precisely to the correct principle of performing the ISN throw. After the fatigue protocol, the angle of both shoulders in the observed variables decreases. In some participants, it decreased so much that they did not use their left hand at all in the initial phase of throwing when the uke's balance was disturbed. Since the uke does not resist, it can be assumed that in a fight without such an action, i.e., a quality kuzushi, the tori would not be able to perform a quality tsukuri. Consequently, such an attempt would end without the possibility of performing the final phase of the kake throw, or even with the performance of a counter throw by the opponent.