Biceps Tendon Changes and Pitching Mechanics in Youth Softball Pitchers

Fastpitch Softball Injuries: Epidemiology, Biomechanics, and Injury Prevention

PURPOSE OF REVIEW

Fastpitch softball is one of the most popular sports among youth and high school female athletes. Despite some similarities to baseball, key differences between the two sports result in different injury patterns, and there is comparatively less literature describing injury epidemiology in fastpitch softball. The purpose of this review is to describe the epidemiology, biomechanics, and injury prevention efforts in regards to fastpitch softball injury with a particular focus on underhand pitching.

RECENT FINDINGS

The injury rate in softball is relatively low and extended time loss injuries in particular are uncommon. Lower extremity injuries are more common overall in softball, but pitchers more often suffer upper extremity injury. Pitchers account for a relatively small proportion of all injuries recorded, but represent a similarly small subset of team rosters, with most teams carrying only a few pitchers in total. The underhand pitching motion exerts significant glenohumeral distractive forces and high stress across the biceps-labrum complex. Core and lower extremity strengthening play an important role in injury prevention for softball pitchers and position players. Fatigue and number of games pitched are tied to increased strength deficiencies and pain in fastpitch softball pitchers, yet pitch count limits are not employed in any major fastpitch softball leagues. While overall injury incidence is low in fastpitch softball players, the potential for overuse injury in pitchers in particular is noteworthy and not nearly as scrutinized as within the baseball community. Critical longitudinal tracking of softball injuries at varying levels of play would be helpful to better understand the sport's injury risk. There are currently no formal pitch count limits enforced in a majority of fastpitch softball leagues. Core and lower extremity strengthening, pre-season conditioning, and monitoring of pitchers for signs of fatigue may be helpful in injury prevention.

Understanding Shoulder and Elbow Injuries in the Windmill Softball Pitcher

Although pitching-related injuries in the overhead athlete have been studied extensively, injuries associated with windmill pitching are not as clearly elucidated. Windmill pitching produces high forces and torques in the upper extremity, and studies have shown it creates similar shoulder and elbow joint loads to those reported in baseball pitchers. Studies have shown that the windmill pitching motion generates high levels of biceps activation with an eccentric load, placing the biceps at increased risk for overuse injuries. Although the American Orthopaedic Society for Sports Medicine published prevention guidelines including recommendations for maximum pitch counts in softball, these recommendations have not been adopted by most United States softball governing bodies. The repetitive windmill motion in conjunction with high pitch count demands in competitive softball creates notable challenges for the sports medicine physician. As with overhead throwing athletes, identifying and preventing overuse is crucial in preventing injuries in the windmill pitcher, and prevention and rehabilitation should focus on optimizing mechanics and kinematics, core, hip, and lower body strength, and recognition of muscle fatigue. With more than two million fastpitch softball participants in the United States, it is essential to better understand the etiology, evaluation, and prevention of injuries in the windmill pitching athlete.

Effects of Increasing Pitch Count on Pitch Type Ball Metrics and Release Height in High School Softball Pitchers

BACKGROUND

Softball research has investigated changes in physical characteristics, mechanics, and ball speed as elements of fatigue. However, the influence of pitch volume on ball metrics is unclear. The purpose of this study was to investigate the influence of pitch volume on ball performance and release metrics in softball pitchers across different pitch types.

HYPOTHESIS

As pitch volume increased, there would be a decrease in ball metrics of the fastball and changes in breaking pitches would be observed earlier than the fastball or changeup.

STUDY DESIGN

Descriptive laboratory study.

LEVEL OF EVIDENCE

Level 5.

METHODS

A total of 21 (15.4 ± 1.6 years; 1.6 ± 0.2 m; 76.0 ± 17.2 kg) softball pitchers participated. Procedures consisted of participants pitching a simulated game consisting of 100 pitches, taking a 30-minute break, and then throwing 12 pitches to simulate the first inning of a doubleheader. Participants randomly threw each pitch type (fastball, changeup, curveball, or dropball). Ball performance and release metrics were measured using a Rapsodo portable pitch tracker.

RESULTS

A 3 (time) by 4 (pitch type) multivariate analysis of variance revealed that pitch speed was significantly higher in the first inning compared with the last inning and the doubleheader inning. The fastball, curveball, and dropball revealed a significant difference in pitch speed between timepoints. Specifically, the curveball and dropball first-inning pitch speed was significantly greater than the last and doubleheader inning. Alternatively, the fastball had a significant increase in pitch speed from the last inning to the doubleheader inning.

CONCLUSION

The typical 30-minute break given between games for doubleheaders may be sufficient recovery time for the fastball but not for the curveball and dropball.

CLINICAL RELEVANCE

The Rapsodo device is an accessible method of tracking ball performance and pitch release metrics and could be helpful in identifying when a pitcher may be experiencing performance detriments in response to increasing pitch count.

Differences in the Medical Advisability of Online Pitching Recommendations for Youth Softball Players Based on Website Source

Background

Guidelines regarding injury prevention in fast-pitch softball pitchers have yet to be widely adopted, risking the online dissemination of misleading advice.

Purpose/Hypothesis

The purpose of this study was to assess the source and medical advisability of online pitching recommendations for youth softball players and highlight the risk of misinformation. It was hypothesized that many popular websites would contain content discordant with current medical guidelines regarding windmill softball pitching recommendations.

Study Design

Cross-sectional study.

Methods

A Google search using the phrase "youth softball pitching recommendations" was performed. Up to 100 websites were extracted and analyzed for website source type (commercial, medical/educational, or athletic organization) and informational quality (advisable, neutral, or discordant). The latter was determined with respect to the STOP Sports Injuries guidelines for arm injury prevention in youth softball players. Descriptive and inferential statistics were used to assess potential associations between website source type and the informational quality of content therein.

Results

A total of 86 websites were included in the analysis. Website source type was significantly predictive of informational quality (P = .018). Among the 3 source types, medical/educational websites had the highest proportion classified as advisable (12/24 [50.0%]) and the lowest proportion classified as discordant (3/24 [12.5%]). Only 17.6% (6/34) of commercial websites were advisable, and advisable websites as a whole were more likely to be from medical/educational sources than athletic organization (P = .016) or commercial (P = .026) sources. The advisability rate among all websites was 25.6% (22/86). Although there was a significant association between position in the search results (first 10 vs remaining 76) and website source type (P = .006), there was no association between position and informational quality (P = .116). The first 10 websites, which trended toward greater advisability than the remaining 76 websites (P = .060), were more likely than the remaining websites to be medical/educational sources (P = .002).

Conclusion

Website source type was significantly predictive of medical advisability. Medical/educational websites were the most advisable, while commercial and athletic organization websites were especially poor in their advisability. The overall advisability rate was only 25.6%. When making recommendations to patients, sports medicine providers should highlight the prevalence of discordant online softball pitching guidelines and take the opportunity to share medically advisable resources.

Biomechanics Related to Increased Softball Pitcher Shoulder Stress: Implications for Injury Prevention

BACKGROUND

Softball pitchers exhibit high throwing shoulder distraction force, which is a theorized mechanism of throwing shoulder overuse injury. Windmill pitching involves a variety of highly individualistic pitching styles, and certain kinematics preceding ball release likely influence the amount of shoulder stress that a pitcher accrues.

PURPOSE

To examine the association of trunk and throwing arm kinematics, kinetics, and timing variables with peak throwing shoulder distraction force in high school softball pitchers.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 37 high school pitchers (mean ± SD; height, 1.71 ± 0.06 m; weight, 75.53 ± 16.12 kg; age, 16 ± 2 years) threw 10 fastball pitches at regulation distance (43 ft [13.1 m]) and with maximum effort. Kinematic data were collected at 240 Hz using an electromagnetic motion capture system synced with motion analysis software. The 3 fastest pitches were averaged and analyzed. Kinematic, kinetic, and timing variables were entered into a stepwise linear regression analysis.

RESULTS

Four variables were included in the significant model (F_4,39 = 147.51; P < .001) and explained peak shoulder distraction force (R² = 0.944; adjusted R² = 0.938; SE = 0.036): increased peak elbow distraction force (t = 19.90; P < .001) and extension moment (t = 3.63; P = .001), as well as decreased elbow flexion velocity (t = -2.37; P = .023) and trunk flexion at foot contact of the pitch (t = -3.00; P = .005).

CONCLUSION

Elbow kinetics and angular velocity, as well as trunk positioning at foot contact, are associated with peak throwing shoulder distraction force in high school softball pitchers.

CLINICAL RELEVANCE

Variables associated with peak throwing shoulder distraction force provide information regarding injury mechanism and coachable cues that might reduce shoulder injury risk among pitchers.