Increased Medial Elbow Torque Is Associated With Ball Velocity Rather Than a History of Medial Elbow Injuries in Youth Baseball Pitchers.

ABSTRACT

PURPOSE: This study compared medial elbow torque in youth baseball pitchers with and without a history of medial elbow injuries to determine the relationship between medial elbow torque during pitching and having a history of medial elbow injuries. METHODS: We recruited 171 youth baseball pitchers aged 9 to 12 years old. The exclusion criteria included current pain with pitching, history of surgery on the tested extremity, or osteochondritis dissecans of the humeral capitellum. The participants were grouped into 3 groups injury <1-year, injury >1-year, and control, based on ultrasonographic abnormalities of the elbow and the presence of elbow pain. Pitchers pitched 3 fastballs while wearing a sensor sleeve that recorded the medial elbow torque, arm speed, and shoulder rotation. Ball velocity was measured using a radar gun. RESULTS: The final analysis included 164 pitchers. Thirty were assigned to the injury <1-year group, 34 to the injury >1-year group, and 100 to the control group. The medial elbow torque was significantly greater in the injury <1-year group compared with the control group (18.6 ± 3.6 Nm vs 16.2 ± 4.8 Nm, P = .023). A multiple regression analysis revealed that ball velocity (B = 0.282, P < .001) and body weight (B = -0.224, P < .001) were significantly associated with medial elbow torque, but not with the history of medial elbow injuries. CONCLUSIONS: Increased medial elbow torque was associated with greater ball velocity regardless of the history of medial elbow injuries. Youth baseball pitchers with a history of medial elbow injuries within one year had greater medial elbow torque during pitching; however, having a history of medial elbow injuries was not an independent factor in increasing medial elbow torque. Limiting the ball velocity can reduce medial elbow torque and may prevent elbow injuries in youth baseball pitchers. LEVEL OF EVIDENCE Level II, prospective comparative prognostic investigation with the patients enrolled at different time point.