## 4 Discussion
Preceding electromyographic studies comparing different trunk flexion speeds showed that the highest exercise speeds require the highest activation levels of flexor and extensor trunk muscles [16]. Correspondingly, research has primarily focused on the effect of hip flexion, supported segments, arm and hand position, knee and hip position, movement of the upper body vs. lower body, and the use of equipment on trunk muscle response [17]. However, looking at the broader ability of the motor system and trunk muscular to maintain stability during the axe throw, throwing ability is affected by a myriad of variables, including experience, strength, throwing velocity, release height, training, and biomechanical efficiency. Thus, because both the mediolateral and anteroposterior acceleration of the trunk CoM trended toward significant variations between the participants, an interplay exists between the upper and lower magnitudes in both the anteroposterior and mediolateral directions. The primary influence might be a mediolateral shift, which may act as a lead axis, progressively leading to eventual inferior axe throwing performance. The anteroposterior and vertical directions, which are mainly involved in symmetrical motion during the throwing phase of the axe throw, were observed to have the widest dispersed acceleration in relation to the participant group mean. It is possible that the differences in these acceleration channels could be due to the participants' expertise, or lack of, in performing axe throwing. Correspondingly, in this case, a lower level of expertise/training may contribute to a reduction in accuracy, possibly when the release speed intensifies. Traditional studies on the speed-accuracy trade-off in aimed movements found higher errors when the movement was performed at a faster pace [18; 19]. Therefore, the lack of task experience in some participants and the relative lack of trunk strength may explain the significant effect of medial-lateral sway. Nevertheless, the interaction between trunk motion control, task experience, task constraints, and performance must be explored in future studies. The results suggest that some of the throwers, namely, those with more experience, may have greater control of their vertical acceleration. This would, in turn, enable greater efficiency when aiming the axe at the center of the target (i.e., the bullseye). The important factor here was that the magnitude of change between throws one and five remained relatively stable, as evidenced by the non-significant result (Table 2). As Figure 2 shows, the linear vertical variability increased during throws three and four. Taking into account fluctuations that reflect the neuromuscular system's response to control the body motion [20], the results from the current study may suggest that some of the participants produced a greater neuromuscular effort in order to control, or stabilize, the trunk motion during the throwing action. Some additional considerations should be made regarding the throwing motion, however. If the thrower's goal is to maximize the length of the throw, he or she must find the optimal combination of the three variables (speed, angle, and height of release) [21]. With the axe throwing technique deployed by participants in the current study, even considering all of the subjective technical interpretations, the release height may be strongly conditioned by the anthropometric characteristics of the thrower. These results could suggest that alternations to release height and/or release angle altered the trunk and magnitude of acceleration. However, to entirely understand the development and impact that axe throwing velocity has on the trunk, three parameters must be taken into account: The tangential velocity, the angular velocity, and the radius of instantaneous rotation.