Players' satisfaction with daily pitching performance could predict shoulder and elbow injuries in high-school baseball pitchers: a prospective time-to-event study.

HYPOTHESIS AND BACKGROUND: The relationship between baseball pitchers' satisfaction with their performance and the incidence of shoulder and elbow injuries is unclear. We hypothesized that self-evaluated satisfaction with pitching performance before an injury and incidence of shoulder and elbow injuries are related. METHODS: Baseline data on baseball experience, height, weight, elbow and shoulder range of motion, and shoulder muscle strength of high-school baseball pitchers were collected. During the season, all participants completed a self-recorded questionnaire regarding satisfaction scores, presence of shoulder and/or elbow pain, and pitching limitations due to shoulder and/or elbow pain experienced daily to determine when injuries occurred and record the satisfaction scores. The optimal satisfaction score cutoff value was determined through receiver operating characteristic curve analysis; participants were categorized into satisfied and unsatisfied groups. Statistical tests were performed to evaluate the differences between the groups, obtain the time-to-event curves, and calculate the hazard ratios for the incidence of injury. RESULTS: Overall, 108 participants aged 15-17 years were enrolled and divided into satisfied (88) and unsatisfied (20) groups. The injury incidence rate was 10.2% and 50.0% in the satisfied and unsatisfied groups, respectively. High-school baseball pitchers with low satisfaction had a significantly increased risk of shoulder and elbow injuries; these players had a 7.3-times greater risk of injuries and 1.9-times earlier occurrence of injuries than pitchers who were satisfied with their performance. CONCLUSION: Daily evaluation of players' self-satisfaction could predict shoulder and elbow injuries in high-school baseball pitchers.

Ankle dorsiflexion deficit in the back leg is a risk factor for shoulder and elbow injuries in young baseball players.

The relationship between ankle joint function and throwing-related injuries has not been demonstrated. We hypothesized that limited ankle joint range of motion (ROM) was related to risk factors for shoulder and elbow injuries in young baseball players. This 12-month prospective cohort study evaluated the age, height, weight, playing position, shoulder, elbow, and ankle function of 228 enrolled baseball players. Shoulder and elbow injuries were tracked during the season. Univariate and multivariate analyses were performed to identify risk factors for shoulder and elbow injuries among participants divided into non-injured and injured groups. Univariate analysis showed that age, height, weight, ROM of elbow flexion in the dominant arm, muscle strength ratio of shoulder abduction, and the likelihood of being a pitcher or a catcher were significantly greater in the injured group than in the non-injured group. ROM of shoulder abduction-external/internal rotation, shoulder total arc on the dominant arm, ankle joint dorsiflexion, and plantar flexion on the back (non-lead) and front (lead) legs were significantly less in the injured group than in the non-injured group. In conclusion, ROM dorsiflexion deficits in the back leg, shoulder abduction-external rotation in the dominant arm, ROM increase in elbow flexion on the dominant side, older age, and being a pitcher were significant independent risk factors for injury.

Pronation and palmar pinch improve the stability of the medial elbow joint space in high school baseball pitchers.

HYPOTHESIS: We aimed to investigate the contributions of grip, pronation, and pinch to stabilization of the medial elbow joint space; examine their relationship with muscle strength; and assess the effect of stabilization on the medial elbow joint space in baseball pitchers. METHODS: In this controlled laboratory study, we measured the medial elbow joint space using ultrasound during the following conditions: unloading; loading; and loading with grip, pronation, and pinch. To evaluate changes in the medial elbow joint space as a result of various conditions, 1-way repeated-measures analysis of variance and post hoc analysis for multiple comparisons were performed. To investigate whether strong or weak muscle strength improved the medial elbow joint space during the loaded condition, Pearson correlation analysis was performed. Finally, a post hoc power analysis was performed. RESULTS: We enrolled 121 pitchers. The medial elbow joint space in the loaded condition, loaded condition with full grip, and loaded condition with full pinch was significantly larger than that in the unloaded condition. The medial elbow joint space in the loaded condition with full grip, loaded condition with full pronation, and loaded condition with full palmar pinch was significantly smaller than that in the loaded condition. A post hoc power analysis showed that the power of the 1-way repeated-measures analysis of variance was 100%. The strengths of the full grip and palmar pinch were significantly correlated with a reduced gap distance of the medial elbow joint space (P < .001 for both). CONCLUSION: In high school baseball pitchers, pronation and palmar pinch contraction significantly improved the gap distance of the medial elbow joint space in the loaded condition and during grip contraction. Moreover, the grip and palmar pinch strengths were significantly correlated with stabilizing effects on the medial elbow joint space.

High baseball loads induce shoulder and elbow injuries among high school baseball pitchers: a prospective study.

Studies on the relationship between baseball loads (practice, training, and competition hours) and shoulder and elbow injuries among high school pitchers are limited. Therefore, this study included 92 male high school baseball pitchers and evaluated their preseason shoulder and elbow conditions. All participants completed a self-recorded questionnaire regarding baseball load, presence of shoulder pain or elbow pain, or both, and pitching limitations due to shoulder and/or elbow pain experienced daily to determine the occurrence of injuries and record the baseball load. The optimal load cutoff value was determined using a receiver operating characteristic curve analysis. Participants were categorized into high-load and low-load groups according to the aforementioned cutoff value. The Kaplan-Meier method was used to obtain time-to-event curves, and cox proportional hazards models were used to calculate the hazard ratios for injury rates. The cutoff value of the average baseball load was 324.4 min per day. A high load (> 5.5 h/day) led to a 2.6-times greater risk of injuries and 3.3-times earlier occurrence of injuries than a low load (< 5.5 h/day). Therefore, a high load is a risk factor for shoulder and elbow injuries in high school baseball pitchers.

A small number of daily pitches induces shoulder and elbow injuries among high school baseball pitchers: a prospective study.

Baseball players frequently injure their shoulders and elbows. Preseason risk factors for such injuries have been relatively well studied, but in-season risk factors are less known, and the relationship between the number of pitches and the incidence of such injuries in baseball pitchers of any level is unclear. Identifying the risk factors related to the number of daily pitches is particularly important to prevent baseball-related arm injuries among young pitchers. Thus, we prospectively investigated the relationship between the number of daily full-power pitches in high school baseball pitchers and the incidence of shoulder and elbow injuries. We observed that a small number of daily full-power pitches, < 30 pitches per day, in high school baseball pitchers, significantly increased the risk of shoulder and elbow injuries: these players had a 2.3-times greater risk of injuries and a 45-day earlier occurrence of injuries than those pitching ≥ 30 pitches per day. Although unexpected, this was plausible as continuous daily pitching is required to maintain physical condition in growing and maturing high school pitchers. These findings may form the basis for establishing guidelines regarding the appropriate number of daily pitches required to prevent shoulder and elbow injuries in high school baseball pitchers.