## 4 Discussion  
This study investigated the CoM position and velocity of the top gymnast, the base gymnast, and the overall system. The application of the LCS revealed distinct patterns in the position and velocity curves, highlighting the distinct contributions of each role, particularly the top gymnast's. Differences were found between the spatial-temporal variables according to the experience level of the pairs, with higher experience translating into faster movements, potentially reflecting more efficient coordination and control. Cross-correlation results indicated that ME pairs exhibit smaller time delays in position curves, suggesting better synchronization, while the longer time delays observed in velocity curves may reflect more refined adaptations to task demands. These findings contribute to a better understanding of how experience influences interpersonal coordination in ACRO biomechanics, offering insights into training practices that may enhance performance and safety. Since no studies were found describing the kinematics of acrobatic gymnasts performing partner-assisted flight, our first approach was to describe the movement, as the first step for understanding and analyzing motion [41]. Our results showed different amplitudes for each position and velocity curve, underlining different participations for each role. Since bases present larger anthropometric measurements [42] and are responsible for throwing the top, there is an assumption that the movement of the bases is the major contributor to the pair's motion. Accordingly, the motion of the top GCS is dependent on the base's position, while the top LCS occurs only due to the individual motion of this gymnast. For example, in Figure 1, the TO Pos of the top LCS results from the top gymnast's own body extension and the raising of the upper limbs, while the TO Pos of the top GCS also incorporates the movement of the base gymnast. The reduced independent movement observed in the top gymnast, particularly in the LCS, indicates a more passive role during skill execution. This passivity may stem from factors such as fear of falling or uncertainty about controlling the aerial phase. Such behaviors can impact the gymnast's ability to actively contribute to the movement, potentially affecting overall performance. Recognizing these patterns can help coaches implement specific drills to build confidence, encourage more active participation, and improve coordination with the base gymnast. We also highlight that between MU Vel and TO Vel, the top LCS curve shows a relevant downward motion, followed by an upward motion just before take-off (Figure 1), which \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Variables**} & \multicolumn{3}{c}{**TOP GCS-BASE**} & \multicolumn{3}{c}{**TOP LCS-BASE**} \\ \cline{2-7}  & **LE** & **ME** & \(p\) **(ES)** & **LE** & **ME** & \(p\) **(ES)** \\ \hline Position r\({}_{\text{max}}\) & 0.98 (0.01) & 0.98 (0.01) & 0.45 (0.14) & 0.97 (0.02) & 0.98 (0.01) & **0.02 (0.43)** \\ Position r\({}_{0}\) & 0.98 (0.02) & 0.98 (0.01) & 0.81 (0.04) & 0.95 (0.04) & 0.96 (0.02) & **\textless{0.001 (0.64)**} \\ Position lag (\%movement) & 0.90 (1.00) & 0.65 (1.00) & **0.03 (0.39)** & 2.80 (2.60) & 1.40 (4.00) & **\textless{0.001 (0.62)**} \\ \hline Velocity r\({}_{\text{max}}\) & 0.95 (0.03) & 0.96 (0.02) & 0.20 (0.24) & 0.84 (0.10) & 0.85 (0.05) & 0.28 (0.20) \\ Velocity r\({}_{0}\) & 0.82 (0.10) & 0.82 (0.06) & 0.36 (0.17) & 0.78 (0.16) & 0.82 (0.07) & **0.01 (0.48)** \\ Velocity lag (\% movement) & 5.10 (2.20) & 5.75 (1.00) & **0.01 (0.47)** & \(-1.20\) (4.50) & \(-1.75\) (3.80) & 0.06 (0.34) \\ \hline \end{tabular}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Legend: Values reported as median (interquartile range). Lag: the time delay between r\({}_{\text{max}}\) and r\({}_{0}\). Statistically significant differences are highlighted in bold. _p_\(\leq\) 0.05, ES, effect-size [40].**} \\ \end{tabular}
\end{table}