## 4 Discussion  
The present study, a pilot project in what is a burgeoning competitive sport, investigated the effect of five one-handed overarm axe throws on performance accuracy and the magnitude of trunk CoM acceleration in male and female axe throwers of varying skill levels. Specifically, the magnitudes of anteroposterior (AP), vertical (V), and mediolateral (ML) acceleration of the trunk in five male and five female axe throwers were investigated while the participants kept all other conditions fixed, including the total duration of the task, which in this case was equal to approximately two minutes. To assess trunk CoM acceleration, the minimum and maximum magnitudes of triaxial acceleration were analyzed in all participants using data from a wearable sensor. Data were obtained in the field using an accelerometer, iPhone, and iPad to capture all throwing movements in what was representative of a typical competitive setting. To the best of our knowledge, this is the first study to explore these topics in what remains an underrepresented sport in terms of applied field-based kinematic research. The results from the current study indicate significant variation in anteroposterior and mediolateral acceleration of the trunk CoM during the five one-handed overarm axe throws, thus denoting changes in trunk motion in both male and female throwers (Table 2). Furthermore, changes in trunk CoM acceleration during each of the five axe throws were analyzed. These changes revealed a somewhat transient yet fluctuating approach to trunk CoM motion with a large magnitude of mediolateral acceleration observed during Throw 1 (2.97 m/s2, Table 2) and a lesser mediolateral magnitude seen during Throw 5 (2.78 m/s2, Table 2). While a significant difference in mediolateral acceleration was seen, the variation within both male and female throwers was notable at \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Gender**} & **Mean** & \multirow{2}{*}{**CV**} & \multirow{2}{*}{\(p\)} & **Mean** & \multirow{2}{*}{**CV**} & \multirow{2}{*}{\(p\)} & **Mean** & \multirow{2}{*}{**CV**} & \multirow{2}{*}{\(p\)} \\  & \(\pm\) SD & & & & \(\pm\) SD & & & \(\pm\) SD \\  & **AP (o m/s2 ** & & **V (y) m/s2** ** & & **ML (z) m/s2** ** & & & \\ \hline Male & 0.463 & \(\pm\) 0.12 & 27.4\% & \(<\)0.0001 * & \(\pm\) 1.87 & \(\pm\) 0.125 & \(\pm\) 0.05 & & \\ Female & 0.489 & 21.3\% & & & 0.395 & & 3.550 & & \\  & \(\pm\) 0.10 & 21.3\% & & & 0.745 & & \(\pm\) 1.78 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mean \(\pm\) SD magnitudes of trunk CoM acceleration differences in female (\(n\) = 5) and male (\(n\) = 5) axe throwers during the performance of five one-handed overarm axe throws were determined. CV = coefficient of variation. Where AP is anteroposterior, V is vertical, and ML is mediolateral acceleration in meters per second per second (m/s2). * Statistically significant at \(p\) < 0.05. Figure 6: Representative example of the magnitudes of trunk CoM acceleration in a female (**left**) and male (**right**) during performance of one overarm axe throw. Where x is anteroposterior, y is vertical, and z is mediolateral acceleration of the trunk CoM. 49.2%. One possible reason for the higher acceleration magnitude observed during Throw 1 could be due to participants essentially warming up and trying to stabilize the trunk in preparation for the subsequent throws. Although the participants performed a self-selected warm up, when faced with a competitive situation (e.g., throwing repetitively whereby accuracy is measured), a modicum of mediolateral sway may have occurred initially until greater stability is achieved. More research to confirm this proposition is required, however. Moreover, the mediolateral acceleration variation contrasted with that of 23.2% that was observed in the anteroposterior direction and 16.5% in the vertical direction.