The relationship between changes in elbow valgus laxity and forearm flexor strength during repetitive pitching

This study examined the changes in the medial elbow joint space width and forearm flexor strength due to repetitive pitching and analysed the relationships among these factors. Thirty-one collegiate baseball players pitched seven sets of 15 pitches each. The medial elbow joint space width, grip strength, and forearm flexor strengths were measured before pitching and after each set. These parameters were compared at baseline and after pitching for each set. Additionally, the relationships between changes in the medial elbow joint space and forearm flexor strength were examined for each set. The medial elbow joint space width significantly increased after four sets compared to baseline values. Compared to baseline values, grip strength decreased significantly after one set, wrist flexion and radial deviation after six, and ulnar deviation after five. However, changes in the medial joint space compared to baseline values after each set were not significantly correlated with changes in forearm flexor strength variables. Therefore, repetitive pitching causes an increase in elbow valgus laxity and a decrease in forearm flexor strength. However, the decrease in forearm muscle strength does not explain the increase in elbow valgus laxity.