How much valgus instability can be expected with ulnar collateral ligament (UCL) injuries? A review of 273 baseball players with UCL injuries

Use of an Elbow Brace During Repetitive Pitching Does Not Cause an Increased Mechanical Burden on the Throwing Arm

“…Until now, various injury prevention programs have been carried out to try to prevent elbow injury in baseball players. These include studies of pitching form using a three-dimensional motion analysis system, [29][30][31][32] studies of the relationship between physical functions and injuries, 22,33 basic studies on the elbow joint by evaluation such as using ultrasound scanning or radiographs, [10][11][12][13][14][15][16][17][18] and encouraging a limitation of the number of pitches in a game. 20,34 However, although these prevention projects have been carried out, it is reported that the number of UCL reconstruction surgeries in recent years has increased, 35 suggesting that these preventative measures are not effective or are not being used effectively.…”

“…Previous studies have demonstrated asymmetrical changes of medial elbow joint space gapping for a prolonged period as a result of habitual or repetitive baseball pitching. [10][11][12][13][14][15][16] Even after pitching only 60 balls, there is an immediate increase in medial elbow joint space gapping, likely due to a phenomenon called cyclic creep. 17 It is suggested that repetitive pitching causes a burden on the medial elbow joint, and may lead to overuse injury.…”

Ultrasound‐Assisted Assessment of Medial Elbow Stability

“…A recent study compared the width of the medial joint space of patients with partial and complete tears to unimpaired elbows. 3 Patients with UCL injuries were found to have greater medial elbow widths than control participants. The width of the medial elbow joint space during valgus stress can be an indicator of UCL laxity.…”

“…R epeated overhead throwing activity has been associated with increased medial elbow instability. [1][2][3] Waris 4 investigated the medial elbow instability of javelin throwers, and athletes with increased elbow instability were found to have an increased risk of becoming unable to participate for durations ranging from a few weeks to a year. Tajika et al 2 reported that decreased athletic performance, a decreased elbow range of motion, and greater elbow pain were associated with an increase in the width of the medial elbow joint space of high school baseball pitchers.…”

“…The anterior bundle of the UCL provides the greatest valgus restraint between 308 and 908 of elbow flexion; at flexion angles of greater than 908, the posterior band of the UCL contributes more restraint to valgus loads to the elbow. 3,6 A thorough evaluation of the stability of the medial elbow must be performed at multiple elbow flexion angles.…”