## 2 Materials and Methods
### Instrumentation
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Characteristics**} & \multicolumn{2}{c}{**AG (\(n\) = 20)**} & \multicolumn{2}{c}{**SG (\(n\) = 20)**} & \multicolumn{2}{c}{**Comparison between Groups**} \\ \cline{2-6}  & **Md \(\pm\) IR** & **Md \(\pm\) IR** & **S-Value (U)** & **\(p\)-Value** \\ \hline Body mass (kg) & 57.500 \(\pm\) 12.750 & 62.500 \(\pm\) 15.500 & U = 248.000 & \(p\) = 0.201 \\ \hline \multirow{4}{*}{\begin{tabular}{c} Height (m) \\ BMI (kg/m\({}^{2}\)) \\ Age (years) \\ \end{tabular} } & mean \(\pm\) SD & mean \(\pm\) SD & S-value (t) & \(p\)-value \\  & 1.651 \(\pm\) 0.069 & 1.651 \(\pm\) 0.058 & t \(=-\)0.025 & \(p\) = 0.980 \\  & 22.313 \(\pm\) 3.158 & 23.467 \(\pm\) 3.105 & t \(=-\)1.166 & \(p\) = 0.251 \\  & 42.050 \(\pm\) 12.808 & 44.000 \(\pm\) 13.294 & t \(=-\)0.472 & \(p\) = 0.639 \\ \hline \multirow{4}{*}{\begin{tabular}{c} Scapular \\ positioning \\ \end{tabular} } & \multirow{4}{*}{Without changes} & frequency (\(n\)) & frequency (\(n\)) & Fisher Exact Test & \(p\)-value \\  & 45\% (\(n\) = 9) & 0\% (\(n\) = 0) & 14.381 & \(p\) = 0.001 * \\ \cline{1-1} \cline{3-5}  & & 55\% (\(n\) = 11): & 100\% (\(n\) = 20): & 14.381 & \(p\) = 0.001 * \\ \cline{1-1} \cline{3-5}  & \multirow{2}{*}{Presenting a} & \multirow{2}{*}{\
\begin{tabular}{c} types II, \(n\) = 7 \\ type II + III, \(n\) = 4 \\ type II + III, \(n\) = 4 \\ type II + III, \(n\) = 9 \\ type II + III, \(n\) = 9 \\ \end{tabular} } \\ \cline{1-1} \cline{3-5} Gender & & Female & 90\% (\(n\) = 18) & 90\% (\(n\) = 18) & - & \(p\) = 1.000 \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Gender \\ \end{tabular} } & \multirow{4}{*}{Legend: AG—asymptomatic group; IR—interquartile range; Md—median; SD—standard deviation; SG—symptomatic group; S-value—statistical value; Significant results were signed with a *.} \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \cline{1-1} \cline{3-5}  & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Groups’ demographic characteristics. through a differential amplifier with an adjustable gain (20-450 Hz; common mode rejection coefficient: 95 dB at 50 Hz and gain of 1000). The EMGworks Acquisition software version 4.5.3 (Delsys Inc., Natick, MA, USA) assessed the signal quality and recorded the EMG data, including the submaximal voluntary contractions for normalization, at an acquisition frequency of 2000 Hz. Subsequently, EMGworks Analysis (Delsys Inc., Natick, MA, USA) was used to filter and analyze EMG data. Additionally, to allow for kinematic and EMG synchronization, another Trigno(tm) sensor was placed on the hand to record accelerometry data. These data were used to identify the beginning of each shoulder movement and drinking task in the electromyographic signal. This time event identification by both the Trigno(tm) system and the KINETIKOS CE-marked (Class I medical device) cloud-based platform enabled the synchronization between kinematic and electromyographic signals. To control the cadence of shoulder elevation and lowering movements, a metronome (Metronome Beats, version 6.5.1, Stonekick, London, UK) was used at 20 beats/min. Shoulder pain intensity was quantified using the self-reported NRS, ranging from 0 (\"no pain\") to 10 (\"unbearable pain\") [52], which has been demonstrated to be reliable (test-retest intraclass correlation coefficient of 0.84 [53]). The Portuguese version [54; 55] of the Shoulder Pain and Disability Index (SPADI), presenting an internal consistency of \(\alpha\) = 0.75-0.84, was used to classify shoulder function in symptomatic subjects, with a score ranging from 0 (\"no pain/no difficulty\") to 100 (\"worst pain imaginable/so difficult required help\") [56]. Scapular presentation from participants of both groups was classified using the scapular dyskinesis classification test (intratester reliability ranging from k = 0.49-0.59 [48]).