# Defining the Influence of Fatigue Protocol on Kinematic Parameters of Ippon Seoi Nage
## 1 Introduction  
Technical efficiency, in addition to conditioning, is an important factor for success in judo, a very complex sport of high intensity [1]. In order to overcome an opponent, a judoka must execute an offense technically correctly and quickly in order to score points and throw the opponent during a fight. Observing a fight structurally, by dividing it into a fight in a standing position and a fight in the parterre, most actions, offenses, and defenses take place in a standing position. Consequently, the highest points are achieved in a standing position by applying throwing techniques [2, 3, 4, 5]. A large number of throwing techniques that a judoka can perform during a fight make this sport demanding and complex. However, research shows that certain throws are performed more often by judokas in fights. During a fight, after the kumikata, that is, grip fighting, the competitor tries to build a situation from which he will be able to launch an offense in order to overcome the opponent [6]. Since the tempo of the fight is highly intense, it is necessary for the competitor to be physically very well prepared. In situations where the fight between two judokas is tied, the result depends on who will be more affected by fatigue, while still being able to perform the throwing technique correctly [7, 8]. Biomechanical analysis contributes to a better understanding of throwing techniques [9, 10, 11, 12, 13, 14]. The aforementioned studies are focused on the analysis of throwing techniques by observing kinematic parameters, while a smaller number are focused on observing movement kinetics. This may be caused by the factthat it is currently very demanding to observe the elements of technique in situational conditions [12]. Furthermore, research focused on the study of kinematics (throwing techniques) has not yet proposed a biomechanical model, i.e., an ideal throwing model, or its modal values. There are multiple factors that contribute to this fact. One of the most important is that the assessment of the biomechanical characteristics of throwing techniques cannot be performed under real conditions. Instead, various systems have used, mainly cameras, markers, judo clothing (or lack of), and modified trainers under strictly controlled conditions [9; 10; 11; 12; 13; 14]. Consequently, parameters that would contribute to a better understanding of judo throws cannot be detected or accurately measured. Given that judo consists of numerous elements, the need for a more exact definition of spatial and temporal parameters is becoming more and more important. The use of inertial sensors can make a significant contribution to observing a throwing technique [15]. The authors of [16] studied the uke's angular accelerations in the performance of the'seoi nage' throw, while those of another study [17] determined the kinematic parameters of falls after the performance of the 'osoto gari' throw. In order for the tori to perform a successful throw, all phases must be completed precisely, quickly, and effectively. This creates the need to define the parameters or variables that most affect the effectiveness of a throw. Along with the correct performance of the throwing technique, an important factor in a fight is the influence of fatigue, which can significantly affect the performance of a technique. Research [18; 19; 20] confirms that fatigue significantly affects the performance of a technique of certain sports. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities in plasma strongly reflect muscle injury, as proper biomarkers of muscle fibers disrupture. Furthermore, it was found that CK and LDH indicators increase significantly after a judo fight [21], and have a negative impact on motor abilities. Through segmental analysis of energy consumption, it was found that during the execution of the morote seoi nage throw, the lower extremities are activated the most, followed by the trunk and the upper extremities [22].