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

Assessing Biomechanical and Clinical Outcomes of an Elbow Orthosis Intervention in Youth Baseball: Preliminary Results

Proper orthosis design may help youth baseball players develop safer pitching mechanics to prevent elbow injuries. This study evaluated the impact of a custom elbow orthosis on pitching biomechanics and adverse events. Ten 11-12-year-old players (mean age 11.5 years) from a regional league team were recruited. The inclusion criteria were at least two years of baseball experience. Six players were randomly assigned to the orthosis group, with four in the control group. Anthropometric data and baseline characteristics were recorded. A video analysis assessed elbow flexion angle during pitching at baseline and at 2 months. The frequency of orthosis wear was also tracked. Adverse events during twice-weekly practices were documented. Post-study surveys evaluated orthosis comfort, stability, and safety perceptions. In the orthosis group (n = 6), four participants showed improved elbow flexion angle, and two of the six participants showed almost no change. The overall median difference was 23.5°. In the control group (n = 4), three participants showed improvement, with a median improvement of 5.5°. Twelve adverse events, including pain, were reported by players not wearing orthoses, whereas no events occurred with orthosis use. Individual players in the control group or who did not wear the orthosis correctly experienced multiple episodes of pain from pitching over the study period. This preliminary study indicates a custom elbow orthosis can optimize pitching biomechanics and prevent adverse events in youth baseball players over the course of two months.

Comparison of elbow valgus laxity and medial elbow stabilizer parameters during repetitive pitching between high school baseball players with and without a history of medial elbow injury

BACKGROUND

Adolescent baseball players with a history of medial elbow injury are often reinjured during demanding practice sessions or games. The physical characteristics of baseball players with a history of medial elbow injury have been reported in several previous studies, but the nature of their medial elbow stabilizers is unknown. This study investigated the difference in characteristics of elbow valgus laxity and medial elbow stabilizer parameters between baseball players with and without a history of medial elbow injury, prior to and during repetitive pitching.

METHODS

Sixteen high school baseball players with no history of medial elbow injury (No-Injury group) and 14 high school baseball players with a history of medial elbow injury (Injury History group) participated. The participants pitched 100 fastballs. Medial elbow joint-space gapping and strain ratio indicating tissue elasticity of ulnar collateral ligament (UCL) and forearm flexor-pronator muscles (FPMs) were measured by ultrasound before pitching and following each of five 20-pitch blocks. Student t tests and Mann-Whitney U tests were used to compare each parameter between groups.

RESULTS

Medial elbow joint-space gapping and UCL elasticity were not significantly different between the 2 groups in each pitching block (P > .05). The strain ratio of FPMs before pitching and after 100 pitches in the Injury History group were significantly greater than that in the No-Injury group (No-Injury vs. Injury History group: before pitching, 0.47 ± 0.19 vs. 0.68 ± 0.26, P = .016; 100 pitches, 0.35 ± 0.12 vs. 0.53 ± 0.20, P = .007). In the other pitching blocks, there was no significant difference between groups, but the effect size was medium and showed a similar tendency (20 pitches, P = .069, Cohen d = 0.69; 40 pitches, P = .116, Cohen d = 0.59; 60 pitches, P = .102, Cohen d = 0.62; 80 pitches, P = .058, Cohen d = 0.72).

CONCLUSIONS

The results of this study indicate that FPM elasticity at baseline and during repetitive pitching in players with a history of medial elbow injury was harder than in players without injury history. This may suggest that baseball players with a history of medial elbow injury increase support of their previously injured medial elbow by hardening FPM elasticity to counteract elbow valgus stress generated during pitching, which may lead to long-term change in the FPMs. Therefore, physical management for this change may be important to prevent reinjury in baseball players with a history of medial elbow injury.

Ulnar Collateral Ligament Laxity After Repetitive Pitching: Associated Factors in High School Baseball Pitchers

BACKGROUND

Medial elbow injury is common in baseball pitchers, with evidence of elbow valgus instability after only 60 consecutive pitches. However, the tissue-specific effects of repetitive pitching on medial elbow stabilizers are largely unknown.

PURPOSE/HYPOTHESIS

This study aimed to investigate changes in the ulnar collateral ligament (UCL) and forearm flexor-pronator muscles (FPMs) during repetitive pitching and factors that relate to identified change. We hypothesized that repetitive pitching would increase elasticity of the medial elbow stabilizers and therefore induce laxity.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 30 high school baseball pitchers participated (mean ± SD age, 16.6 ± 0.5 years). Each participant pitched 100 times (5 blocks of 20 pitches). The strain ratio, indicating elasticity in the UCL and FPMs, was measured using ultrasound before pitching and after every 20-pitch block. Data for each pitch block were compared using analysis of variance. Multiple regression analysis was used to investigate factors related to the change rate of the strain ratio.

RESULTS

The strain ratio of the UCL after 100 pitches was significantly less than that before pitching (before pitching, 4.83 ± 1.70; after 100 pitches, 3.59 ± 1.35; P = .013), but this was not the case for the FPMs (before pitching, 0.57 ± 0.24; after 100 pitches, 0.43 ± 0.18; P = .07). The ratio of the strain ratio in the UCL and FPMs (UCL/FPMs) before pitching (β = -0.385; P = .031) and the elbow flexion range of motion before pitching (β = -0.352; P = .046) were significantly and independently correlated with the change rate of the UCL.

CONCLUSION

Elasticity significantly increased for the UCL, indicating laxity, but not for the FPMs after 100 pitches. Furthermore, the ratio of elasticity (UCL/FPMs) and the elbow flexion range of motion before pitching were significantly related to the change rate of UCL elasticity.

CLINICAL RELEVANCE

To reduce laxity of the UCL, pitchers should be limited to <100 pitches per game. Sustaining a lower level of relative FPMs to UCL elasticity at rest and maintaining a large muscle volume to avoid excessive elbow flexion range of motion may prevent UCL laxity that develops during repetitive pitching.