Validity and Feasibility of the Seated Medicine Ball Throw and Unilateral Shot-Put Tests in Assessing Upper Extremity Function in Rotator-Cuff-Related Shoulder Pain

Background: Rotator cuff-related shoulder pain (RCRSP) is a common musculoskeletal condition characterized by pain, functional disability, reduced mobility, and weakness. There is a need for valid functional tests that can measure shoulder strength and power without exacerbating pain. The Seated Medicine Ball Throw (SMBT) and Unilateral Shot-Put Test (ULSPT) are throwing tests that use a weighted ball in a seated position, measuring throwing distance (m). This study aimed to evaluate the feasibility, discriminative validity, and convergent validity of these tests in individuals with RCRSP. Methods: This cross-sectional study included 64 participants: 30 with RCRSP and 34 asymptomatic controls. Participants completed the QuickDASH and Fear-Avoidance Beliefs Questionnaire (FABQ). Pain was assessed using a 10 cm visual analog scale (VAS) at multiple time points. The SMBT and ULSPT were performed using a 2 kg ball, with throwing distance calculated as the average of three trials. Active shoulder range of motion (AROM) and grip strength were also measured. A two-way mixed-model repeated-measures ANOVA was conducted to examine group effects, with post hoc analyses performed where relevant. Pearson correlations explored associations among outcome measures. Results: The RCRSP group presented with persistent moderate shoulder pain (mean duration = 6.33 ± 5.7 months, VAS = 5.03 ± 1.99 cm, QuickDASH = 26.2 ± 10.54). Pain did not significantly increase after throwing (VAS change = 0.5 ± 1.6 cm, P = 0.4), supporting the tests’ feasibility. ULSPT demonstrated significant differences between the RCRSP and control groups for both symptomatic (2.03 ± 0.81 m) and asymptomatic shoulders (2.04 ± 0.8 m) compared with controls (2.51 ± 0.93 m, P < 0.01). SMBT showed a trend toward group differences (P = 0.05). RCRSP participants showed reduced AROM (166.2 ± 10° vs. 175.1 ± 8.2°) but similar grip strength compared to controls. ULSPT strongly correlated with SMBT (r = 0.92–0.94, P < 0.0001). Both throwing tests correlated moderately with grip strength (r = 0.61–0.81, P < 0.05) and showed mild to moderate correlations with disability, pain, and fear-avoidance measures (r = 0.26–0.48, P < 0.05). Conclusions: The ULSPT demonstrated good discriminative validity in differentiating individuals with RCRSP from controls, while the SMBT showed a trend toward discrimination. Both tests were feasible to administer without significantly exacerbating pain. The strong correlation between ULSPT and SMBT, along with their associations with established measures, supports their potential as functional assessments of upper extremity performance in RCRSP.