Kinematic Differences Exist Between the Fastball, Changeup, Curveball, and Dropball Pitch Types in Collegiate Softball Pitchers

Abstract

Background: A majority of softball literature focuses on the mechanics associated with pain and injury within a single pitch type per study; however, the generalizability of these findings is unknown since a kinematic comparison has yet to be performed between pitch types. Understanding kinematic differences between pitch types can be used to identify risk factors for injury, improve safety guidelines, and improve performance by linking specific mechanics with desired pitch outcomes. Hypothesis/Purpose: The purpose of this study was to compare kinematics between the fastball, changeup, curveball, and dropball pitch types in collegiate softball pitchers. It was hypothesized that there would be significant kinematic differences between pitch types. Study Design: Descriptive laboratory study. Methods: A total of 28 female collegiate softball pitchers pitched 3 trials of each pitch type to a catcher at regulation distance. Pitch speed, stride length, trunk extension, trunk rotation, trunk lateral flexion, elbow flexion, and center of mass for each trial were calculated using an electromagnetic motion capture system and were averaged for analysis. A 1-way analysis of variance (ANOVA) was used to investigate pitch speed differences between the 4 pitch types. A 4 (pitch type) × 5 (event) within-athlete multivariate ANOVA was also used to determine kinematic differences. Results: The results revealed a significant difference in pitch speed between pitch types; a pitch type main effect for trunk extension, trunk rotation, trunk lateral flexion, and center of mass; and an event main effect for all variables except stride length. The results also revealed a pitch type by event interaction for trunk flexion, trunk lateral flexion, and center of mass. Specifically, the dropball type had less trunk extension than the fastball at all pitching events. Similarly, the curveball type had a more posteriorly shifted center of mass than the dropball at the last 3 pitching events of foot contact, ball release and follow-through. Conclusion: Significant kinematic differences exist between pitch types, but these differences may be necessary to execute desired pitch outcomes. Clinical Relevance: This is the first study to analyze kinematic differences between pitch types in softball pitchers. Understanding the effects of different pitch types on kinematic parameters may enhance injury prevention and performance strategies for softball pitchers.

How do athletes cause ball flight path deviation in high-performance interceptive ball sports? A systematic review

“…We also identified softball curveballs that cause lateral deviation of the ball. For this pitch variation, Downs et al 14 reported similar elbow and thorax kinematics to other pitches 49,56,70 indicating that athletes alter other variables that were not measured. While it is well understood how baseball pitching techniques cause lateral deviation of fastballs, it remains unclear how softball pitchers throw curveballs.…”

“…9 Softball pitchers use changeups disguised as fastballs, which arrive later and experience a greater reduction in vertical height due to a slower release speed. 14 Similarly, the dropball pitch is also thrown to appear as a fastball but often has a greater reduction in vertical height due to topspin imparted on the ball. 14 We identified two investigations of softball changeup and dropball pitches in this review.…”

Peak Elbow Flexion Does Not Influence Peak Shoulder Distraction Force or Ball Velocity in NCAA Division I Softball Pitchers

“…First, only the fastball pitch was analyzed; however, prior research showed that elbow flexion does not vary between the fastball, curveball, changeup, and drop-ball pitch types. 5 Second, only the acceleration phase of the pitch was analyzed. Previous research noted that elbow flexion is greatest during the initial upswing of the pitching arm in preparation for the acceleration phase and during follow-through, 10 while the largest shoulder distraction forces occur during the acceleration phase of the pitch.…”

“…4,28 The full-body dynamic motion of the windmill softball pitch also requires the arm to make an approximately 485 arc of motion. 4 The elbow of the throwing arm is mostly extended throughout the circumducted movement 5 and likely contributes to centrifugal distraction force on the shoulder. An extended elbow may also lead to greater ball velocities by mechanically creating a longer lever arm during circumduction, whereas a pitching arm with greater elbow flexion would result in a shorter lever arm.…”

Decreased Shoulder and Elbow Joint Loads During the Changeup Compared With the Fastball and Curveball in NCAA Division I Collegiate Softball Pitchers

“…The limited data in the existing softball literature indicate that trunk kinematics vary among pitch type. 5 Most prior investigations have focused on descriptive kinematic and kinetic data while pitching the fastball, 4 , 16 , 40 , 41 with a small number of studies examining select trunk and shoulder kinematics and kinetics in relation to pain prevalence for the rise-ball and changeup pitches. 17 – 19 Therefore, there are limited data examining joint loads about the upper extremity and pain prevalence across multiple pitch types.…”