## 4 Results
### Convergent Validity  
Table 4 presents the correlation results between the throwing tests and other measures. Key correlations are illustrated in Figure 3.  
SMBT and ULSPT were highly correlated in both groups (r = 0.92, 0.94, \(p\) = 0.0001).  
A good correlation was found between the throwing tests and grip strength in the control group (r = 0.78-0.81), and a moderate correlation was found in the RCRSP group (r = 0.61, 0.7). Mild significant associations were found between the throwing tests and QuickDASH in the RCRSP group (r = (-0.48)-(-0.44)). Fear avoidance was mildly associated with SMBT and ULSPT in both groups (SMBT: control r = \(-\)0.29, \(p\) = 0.03; RCRSP r = \(-\)0.39, \(p\) = 0.02; ULSPT: control r = \(-\)0.42, \(p\) = 0.02). Only a low correlation was found between SMBT and past-week VAS (r = \(-\)0.37, \(p\) = 0.05) in the RCRSP group.  
AROM was correlated with fear avoidance only in the RCRSP group (r = 0.52, \(p\) = 0.002). Mild to moderate correlations were found among QuickDASH, fear avoidance, and past-week VAS (r = 0.35-0.53, \(p\) < 0.05).  
In summary, both SMBT and ULSPT were feasible for individuals with RCRSP to perform, with minimal pain exacerbation (mean increase in pain 0.5 \(\pm\) 1.6 cm, \(p\) = 0.4). The ULSPT demonstrated the ability to discriminate between RCRSP and control groups for both painful and non-painful shoulders. The SMBT did not show significant group differences, although a trend was observed. Both throwing tests showed a strong correlation with each other and a moderate to good correlation with grip strength. Mild to moderate correlations were observed between throwing tests and self-reported measures (QuickDASH, FABQ), and weak correlations were observed with pain intensity (VAS).  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**A**} & \multicolumn{2}{c}{**SMBT (m)**} & \multicolumn{2}{c}{**ULSPT (m)**} \\  & \multicolumn{2}{c}{**r, P**} & \multicolumn{2}{c}{**r, P**} \\  & **Control** & **RCRSP** & **Control** & **RCRSP** \\ \hline ULSPT (m) & 0.92 & 0.94 & 1 & 1 \\  & **<0.0001** & **<0.0001** & ** & **1** \\ Grip (kgf) & 0.78 & 0.70 & **0.81** & **0.61** \\  & **<0.0001** & **<0.0001** & **<0.0001** & **<0.0001** \\ AROM (\({}^{\circ}\)) & \(-\)0.05 & \(-\)0.22 & 0.04 & \(-\)0.2 \\  & 0.65 & 0.21 & 0.77 & 0.30 \\ \hline \multirow{2}{*}{**B**} & \multicolumn{2}{c}{**SMBT (m)**} & \multicolumn{2}{c}{**ULSPT (m)**} \\  & \multicolumn{2}{c}{**r, P**} & \multicolumn{2}{c}{**r, P**} \\  & **Control** & **RCRSP** & **Control** & **RCRSP** \\ \hline QuickDASH (11–55) & **0.03** & **0.0059** & 0.056 & **0.02** \\  & **0.26** & **-0.39** & **0.29** & **-0.42** \\ Fear avoidance (0–66) & **0.03** & **0.02** & **0.02** & **0.02** \\ VAS (past week) (/10 cm) & N.R & **-0.37** & & \(-\)0.29 \\  & **0.04** & **N.R & 0.12 \\ \hline \hline \end{tabular}  
* \(p\) < 0.05, **\(p\) < 0.005 RCRSP—rotator cuff-related shoulder pain (only the painful shoulder), SMBT—seated medicine ball throw, AROM—active range of motion, ULSPT—unilateral shortup test, kgf—kilogram force, QuickDASH—disability of arm shoulder and neck, VAS—visual analog.  
\end{table}
Table 4: Correlation results (r, P): (A) between throwing tests (SMBT and ULSPT) and other physical measures (grip strength and AROM) within the control (n = 68) and RCRSP painful side (n = 30); (B) between throwing tests and self-reported measures (QuickDash, FABQ, and VAS) within the control (n = 34) and RCRSP (n = 30) group.  
Both painful and non-painful shoulders in the RCRSP group showed reduced performance in the ULSPT compared with controls, suggesting potential bilateral effects of unilateral shoulder pain.  
These findings provide initial support for the use of the ULSPT as a functional assessment tool in individuals with RCRSP while suggesting that further investigation may be needed for the SMBT in this population.