## 2 Materials and Methods
### Procedures
#### 2.4.2 Data Acquisition  
The collections were carried out in one moment. For the collection of kinematic data with Qualisys Motion Capture System, 32 reflective markers were placed bilaterally in the anatomical references (identified by manual palpation) needed to identify the movement of the assessed body segments: left and right anterior head (L/RALH), left and right posterior head (L/RPLH), left and right lateral part of the acromion (L/RCAJ), deepest point of incisura jugularis (SJN), xiphoid process (SXS), left and right styloid apopphysis of the ulna (L/RULN) and radius (L/RRAD), left and right anterior superior iliac spine (L/RIAS), left and right lateral prominence of the greater trochanter (L/RFTC), spinous process of the seventh cervical vertebrae (CV7), second thoracic vertebrae (TV2), midpoint between the inferior angles of the most caudal points of the two scapulae (TV7), first lumbar vertebrae (LV1), fifth lumbar vertebrae (LV2), left and right posterior superior iliac spine (L/RIPS), left and right lateral (L/RLELB) and medial (L/RMELB) epicondyle of the humerus, left and right dorsal second metacarpal head (L/RLH), and left and right fifth metacarpal head (L/RMH) [26; 27; 28; 29; 30]. The marker setup is presented in Tables 1 and 2. After placing the reflective markers, participants were instructed on the execution of two therapeutic exercises, namely, a diagonal shoulder exercise (D1) [31] and a multi-joint exercise, including shoulder external rotation at 90\({}^{\circ}\) of shoulder abduction (M90) [32] by a specialized physiotherapist. A description of the exercises used are shown in Table 3. Before data collection, sufficient time was given until the participants became familiar with the experimental setting. Initially, each participant performed the exercises under the supervision of the physiotherapist to collect data from the movements that served as the basis for the comparative analysis--guided exercises (GE). The order in which the exercises were performed was randomized for each participant. After this collection, each participant watched a demonstration video on the application of the exercises to be performed. Subsequently, each exercise was performed unilaterally with the right upper limb three times, without supervision--non-guided exercises (NGE). A resting time of one minute between repetitions was established to prevent fatigue. While conducting the exercises, the optoelectronic system (considered the gold-standard equipment) recorded the 3D kinematics, and simultaneously, a 2D video was captured using a smartphone. \begin{table}
\begin{tabular}{c c} \hline \hline
**Waterior View** \\ \hline
**Marker Name** & **Description** \\ \hline L/RALH & Left/Right anterior head \\ \hline L/RCAJ & Left/Right acromion \\ \hline SJN & Deepest point of incisura jugularis \\ \hline SXS & Xiphoid process, the most caudal point of the sternum \\ \hline L/RIAS & Left/Right anterior superior iliac spine \\ \hline L/RFTC & Most lateral prominence of the greater trochanter \\ \hline L/RRAD & Left/Right distal radius \\ \hline L/RULN & Left/Right distal ulna \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Anterior view of marker setup. \begin{table}
\begin{tabular}{c c} \hline \hline
**Water Name** & **Description** \\ \hline L/RPLH & Left/Right posterior head \\ \hline CV7 & Spinous process of the seventh cervical vertebrae \\ \hline TV2 & Second thoracic vertebrae \\ \hline TV7 & Midpoint between the inferior angles of \\  & the most caudal points of the two scapulae \\ \hline LV1 & First lumbar vertebrae \\ \hline LV3 & Third lumbar vertebrae \\ \hline LV5 & Fifth lumbar vertebrae \\ \hline L/RIPS & Left/Right posterior superior iliac spine \\ \hline L/RELB & Left/Right lateral elbow \\ \hline L/RMELB & Left/Right medial elbow \\ \hline L/RLH & Left/Right dorsal 2 nd metacarpal head \\ \hline L/RMH & Left/Right dorsal 5 th metacarpal head \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Posterior view of marker setup.