## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Outcome** & \multirow{2}{*}{**Side**} & \multirow{2}{*}{**Mean \(\pm\) SD**} & **SEM** & **CV** & \(p\) & **Mean \(\pm\) SD** & **SEM** & **CV** & \(p\) & **r** & **ICC** \\ \cline{3-10}
**Measure** & & & **1 st** & & & & **2 nd** & & & & \\ \hline Total & R & 265 \(\pm\) 110 & 30 & 41 & & 282 \(\pm\) 83 & 23 & 29 & & 0.76 \({}^{*}\) & 0.87 \\ length & L & 288 \(\pm\) 109 & 30 & 37 & 0.06 & 325 \(\pm\) 146 & 40 & 45 & 0.43 & 0.71 \({}^{*}\) & 0.81 \\ \hline Length x & R & 143 \(\pm\) 64 & 17 & 45 & & 180 \(\pm\) 59 & 16 & 32 & & 0.63 \({}^{*}\) & 0.77 \\ (ML) & L & 162 \(\pm\) 77 & 21 & 47 & 0.06 & 214 \(\pm\) 97 & 27 & 45 & 0.39 & 0.86 \({}^{*}\) & 0.91 \\ \hline Length y & R & 206 \(\pm\) 90 & 26 & 43 & & 170 \(\pm\) 68 & 19 & 40 & & 0.55 & 0.64 \\ (AP) & L & 216 \(\pm\) 76 & 22 & 35 & 0.40 & 196 \(\pm\) 70 & 31 & 50 & 0.53 & 0.57 & 0.70 \\ \hline Velocity x & R & 5.73 \(\pm\) 2.5 & 0.71 & 45 & & 8.58 \(\pm\) 3.9 & 1.08 & 45 & & 0.67 \({}^{*}\) & 0.79 \\ (ML) & L & 6.49 \(\pm\) 3.1 & 0.86 & 47 & 0.07 & 7.62 \(\pm\) 2.2 & 0.62 & 29 & 0.26 & 0.86 \({}^{*}\) & 0.91 \\ \hline Velocity y & R & 7.99 \(\pm\) 3.5 & 0.99 & 44 & & 6.90 \(\pm\) 2.6 & 0.73 & 38 & & 0.50 & 0.62 \\ (AP) & L & 8.45 \(\pm\) 3.1 & 0.83 & 35 & 0.29 & 7.99 \(\pm\) 4.2 & 1.17 & 52 & 0.61 & 0.53 & 0.60 \\ \hline Area 95\% & R & 1208 \(\pm\) 606 & 318 & 50 & & 2076 \(\pm\) 875 & 250 & 56 & & 0.53 & 0.62 \\ L & L & 1193 \(\pm\) 630 & 182 & 52 & 0.31 & 2620 \(\pm\) 775 & 312 & 62 & 0.33 & 0.58 & 0.66 \\ \hline \hline \end{tabular} \({}^{*}\)—_p_ value \(\sim\)0.05; SD—standard deviation; CV—coefficients of variation; SEM—standard error of measurement; ICC—Intraclass Correlation Coefficients; r—Pearson correlation coefficient; R—right; L—left.  
\end{table} 
Table 3: Test–retest reliability with eyes open. variations in COP and have been documented in patients with glenohumeral joint instability [11; 22; 23] and in those who have undergone surgical treatment for the shoulder joint [1]. In particular, sensorimotor control deficits are strongly associated with recurrent anterior shoulder instability, especially in individuals with pathology in the dominant shoulder [2]. Notably, COP measurements have revealed post-surgery sensorimotor deficits in patients, even among those with favorable clinical and functional outcomes [1; 2]. Monitoring COP using a force platform in weight-bearing upper-limb positions provides a comprehensive assessment of shoulder sensorimotor control [14], and this could contribute to the evaluation of shoulder pathologies, particularly those involving the rotator cuff and associated therapies [24] COP measurements reveal the body's segmental alignment and the fine adjustments required to maintain the center of gravity over the support base [1; 7; 8]. Sway velocity, in particular, reflects the rate at which the COP shifts, offering insight into the individual's ability to stabilize the upper extremity during movement. Commonly, COP metrics are evaluated in both the medial-lateral and anterior-posterior directions, as distinct muscle groups influence each plane of movement. Velocity-based variables are especially valuable, indicating how quickly adjustments are made to maintain balance throughout a trial and providing a measure of the subject's responsiveness and agility in stabilization. These metrics thus offer a reliable method for assessing upper extremity stability and proprioception, quantifying the shoulder's capacity to sustain control in weight-bearing positions [2; 8; 25; 26; 27; 28]. Performing closed-chain functional testing of the upper extremity in a full plank position requires an individual to support approximately 60% of their body mass, which significantly activates the deltoid and intraspinatus muscles, with moderate engagement of the supraspinatus and pectoralis major [25; 26; 29].