Search Results (3)

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. Full article

Underarm throwing motions are crucial in various sports, including boccia. Unlike healthy players, people with profound weakness, spasticity, athetosis, or deformity in the upper limbs may struggle or find it difficult to control their hands to hold or release a ball using their fingers at the proper timing. To help them, our study aims to understand underarm throwing motions. We start by defining the throwing intention in terms of the launch angle of a ball, which goes hand-in-hand with the timing for releasing the ball. Then, an appropriate part of the body is determined in order to estimate ball-throwing intention based on the swinging motion. Furthermore, the geometric relationship between the movements of the body part and the release angle is investigated by involving multiple subjects. Based on the confirmed correlation, a calibration-and-estimation model that considers individual differences is proposed. The proposed model consists of calibration and estimation modules. To begin, as the calibration module is performed, individual prediction states for each subject are updated online. Then, in the estimation module, the throwing intention is estimated employing the updated prediction. To verify the effectiveness of the model, extensive experiments were conducted with seven subjects. In detail, two evaluation directions were set: (1) how many balls need to be thrown in advance to achieve sufficient accuracy; and (2) whether the model can reach sufficient accuracy despite individual differences. From the evaluation tests, by throwing 20 balls in advance, the model could account for individual differences in the throwing estimation. Consequently, the effectiveness of the model was confirmed when focusing on the movements of the shoulder in the human body during underarm throwing. In the near future, we expect the model to expand the means of supporting disabled people with ball-throwing disabilities. Full article

Objectives: The objective is to compare stiffness changes around the shoulder muscles between pitchers and position players after throwing overhead using shear wave elastography (SWE) in relation to throwing motion analysis and muscle strength. Methods: A total of 32 male college baseball players (12 pitchers and 20 position players) were observed throwing 20 times, and SWE was performed to evaluate 13 shoulder muscle items—tendons (supraspinatus, infraspinatus, subscapularis, and teres minor), muscles (supraspinatus, infraspinatus [transverse and oblique part], teres minor, lower trapezius, latissimus dorsi, and pectoralis minor), and capsules (posterior and posteroinferior). Motion analysis was used to assess elbow torque, forearm angle, forearm rotation speed, and maximum external rotation angle of the shoulder. Muscle strength was measured using a dynamometer for abduction, internal/external rotation of the shoulder at an abduction of 0°, internal/external rotation of the shoulder at an abduction of 90°, and internal/external rotation of shoulder at a flexion of 90°. Results: In the pitcher group, SWE values for the teres minor muscle and latissimus dorsi muscle increased significantly after throwing. In the position player group, SWE values for the teres minor muscle significantly increased, and SWE values of the pectoralis minor muscle decreased after throwing. In the pitcher group, positive correlations were found between the teres minor muscle and forearm rotation speed and between the latissimus dorsi muscle and forearm angle. No significant difference was found in muscle strength after throwing in any of the groups. Conclusions: Stiffness changes occurred after throwing and were related to the motion analysis, but the regions in which stiffness occurred varied between pitchers and position players. Full article