Ultrasound Elastographic Assessment of the Medial Collateral Ligament in the Elbow Joints of Baseball Players

We investigated the elasticity of the medial collateral ligament (MCL) in baseball players using ultrasound elastography (EG). We examined 72 elbows in 36 male baseball players (including 12 junior high students, 12 high school students, and 12 university students) with no history of pitching injuries. We used the Hitachi Medical Corporation HI VISION Avius, an acoustic coupler for quantification, as well as real-time tissue EG, which was applied to subjects in the supine position. Pressure was applied manually with the subject\u27s forearm in supination, elbow joint at 30° of flexion, and shoulder joint at 90° abduction. The strain ratio (SR) of the coupler and MCL was used for evaluation. SR increased with age (P < 0.05) in both arms, and the SR in the university student group was higher than that in the other groups (P < 0.05). In addition, the throwing side exhibited significantly lower SR values compared to the non-throwing side (P < 0.05), but there was no correlation between SR and other factors. Findings and Conclusions: Elasticity in MCLs of baseball players decreases with age, and increases on the throwing side. Quantifying the elasticity of the elbow MCL in this study will facilitate future investigation of how ligament characteristics could affect MCL injuries