Sufficient duration of off-season decreases elbow disorders in elementary school-aged baseball players

Survey with Innovations to Increase Response Rate Reveals Low Compliance with Guidelines among Youth Baseball Coaches - Including a Survey of Differences between Cities

Background

Compliance rates of youth baseball team coaches with guidelines regarding pitch count limits have been reported, but response rates from previous surveys have not been high, which may introduce substantial non-response bias. In addition, differences between cities in guideline compliance rates have remained unclear.

Purpose

The aim of the present study was to obtain data on coach compliance with guidelines for pitch count limits with a high survey response rate. Secondary aims were to determine compliance with guidelines other than pitch count limits, and to determine whether differences in compliance exists between cities.

Methods

A questionnaire was developed for coaches of youth baseball teams in Gunma to assess knowledge of and compliance with the Japan Softball Baseball Association's recommendations for preventing injuries. In the preparation, distribution, and collection of the questionnaire, four strategies were applied to increase the response rate. The questionnaire surveyed basic descriptive information about the team and coach and coaches compliance with guidelines. Survey items were compared between compliant and non-compliant groups for pitch count limits, and by city.

Results

Valid responses to the questionnaire were obtained from coaches of 58 of 62 teams surveyed for a response rate of 93.5%. Despite the fact that almost all coaches were aware of the recommendations regarding pitch count limits and felt these limits were needed, only 15.5% were compliant. For guidelines other than the pitch count limits, the recommended values were exceeded for practice time on holidays. Differences between cities were evident in the compliance rate with the pitch count limit, but no differences between cities in other items were observed.

Conclusion

The results of this research revealed that compliance with pitch count limits in this sample of youth baseball coaches was much lower than previously reported. Differences between cities were identified in rates of compliance with pitch count limits. These results suggest a need to increase compliance rates with guidelines for pitch count limits and to address differences between cities.

Level of Evidence

Cross-sectional survey study, 3b.

The Influence of Chronic Medial Epicondylar Apophysitis on Medial Ulnar Collateral Ligament Insufficiency - Retrospective Cohort Study

Background

This study aimed to investigate the effect of chronic traction apophysitis of the medial epicondyle (MEC) on medial ulnar collateral ligament (MUCL) insufficiency in high school baseball players.

Methods

In this retrospective cohort study, 3034 of 6069 high school baseball players were enrolled. A self-reported questionnaire was distributed to investigate past history of elbow pain and elbow pain during the previous season. Physical examinations to assess tenderness on the MUCL and the elbow valgus stress test (EVST) were performed. Ultrasonography was performed to determine the presence of morphological abnormalities of the anteroinferior aspect of the MEC (MEC lesions).

Results

Participants with MEC lesions had a significantly higher prevalence of past history of elbow pain, elbow pain during the previous season, MUCL tenderness, and positive EVST than those without MEC lesions (P < .05). Multivariate logistic regression analysis revealed that the participants with the fragmented type had the highest risk of past history of elbow pain (odds ratio [OR] = 3.94), elbow pain during the previous season (OR = 2.27), positive EVST (OR = 3.49), and the second highest risk of MUCL tenderness (OR = 2.01) followed by the irregular type (OR = 2.31). Participants with the hypertrophic type had the lowest risk of past history of elbow pain (OR = 2.08), elbow pain during the previous season (OR = 1.42), MUCL tenderness (OR = 1.09), and positive EVST (OR = 1.47).

Conclusion

The presence of chronic non-healed traction apophysitis of the MEC in high school baseball players presented a significantly high risk of elbow pain and MUCL insufficiency.

Professional Baseball Player Type and Geographic Region of Origin Impacts Shoulder External and Internal Rotation Strength

BACKGROUND

Shoulder strength deficits are implicated in arm injuries and performance deficits in baseball players.

PURPOSE

To characterize shoulder external (ER) and internal (IR) rotation strength in professional baseball players, and compare strength across player type (pitchers, position players) and geographic origin (North America, Latin America).

STUDY DESIGN

Cross-sectional.

METHODS

Minor league professional baseball players from North America and Latin America (n=242; age=22.4±2.3 years; n=135 pitchers and n=107 position players; n=162 North American and n=80 Latin American players) volunteered at spring training. Bilateral shoulder IR and ER isometric strength was measured in sitting with the arm at the side using a handheld dynamometer stabilized on a wall via a specialized jig. Strength was normalized to body weight, and compared using t-tests between player type and geographic area of origin (p < 0.05).

RESULTS

Position players had greater strength in ER, IR and ER:IR (ER:0.7-2.7N/kg; IR:1.3-3.8N/kg; ER:IR ratio 0.36-1.22) compared to pitchers (ER:0.5-2.5N/kg; IR:0.6- 4.2N/kg; ER:IR ratio 0.44-1.16) on the throwing arm. North American pitchers had lower ER [MD= -0.4 (95%CI:-0.7,-0.2);p=0.002] and IR [MD= -0.2 (95%CI:-0.4,-0.1);p=0.006] than Latin American pitchers on the throwing arm. There were no differences between geographic groups for position players.

DISCUSSION/CONCLUSIONS

Player position and geographic origin influence shoulder rotational strength values in professional baseball players. Position players have 14 - 20% higher ER and IR isometric strength than pitchers. Moreover, Latin American pitchers exhibited 11.8% greater ER strength and 16.7% greater IR strength as compared to North American pitchers. Normative values can be used to determine player deficits, declines in performance, and targets for return to play after injury.

LEVEL OF EVIDENCE

Level II.

Ulnar Collateral Ligament Reconstruction With the Modified Jobe Technique in Baseball Pitchers

Background:

Tearing and insufficiency of the ulnar collateral ligament (UCL) of the elbow result in valgus instability, which can lead to pain while throwing and decline in performance in overhead athletes.

Purpose:

To assess the clinical results of a modified UCL reconstruction technique using 1 bone hole in the ulna and 1 bone tunnel in the humerus in baseball players.

Study Design:

Case series; Level of evidence, 4.

Methods:

The inclusion criteria were medial elbow pain preventing effective playing, clinically medial elbow laxity, and magnetic resonance imaging results consistent with UCL injury. Patients who were engaged in other sports and in other positions in baseball except pitchers were excluded from this study. Our modified Tommy John procedure was performed via a muscle-splitting approach and an original single-bone-tunnel technique, using a suture anchor. After a minimum of 24 months, patients were evaluated using the Conway scale and the Timmerman-Andrews score.

Results:

Of 31 patients, 20 baseball pitchers (20 male: 5 high school, 5 collegiate, 8 nonprofessional, and 2 professional pitchers) were reviewed. The mean patient age at the time of operation was 21.9 years, and the mean postoperative follow-up period was 35.1 months (range, 24-66 months). The mean Timmerman-Andrews subjective score improved significantly from pre- to postoperatively (from 68.3 to 98.3; P < .05); the objective score also improved significantly (from 81.1 to 96.4; P = .01). No complications were detected at the latest follow-up. Overall, 19 patients were able to return to their preinjury level of sports or higher.

Conclusion:

UCL reconstruction with 1 bone hole in the ulna and 1 bone tunnel in the humerus demonstrated satisfactory results in baseball pitchers. Our modified technique was safe and achieved satisfactory clinical results, with a 95% rate of return to sports.