A Clinician's Guide to Analysis of the Pitching Motion

History of Ulnar Collateral Ligament Injury and College Pitcher Fastball Profiles: A Retrospective, Observational, Live Pitching Analysis

PURPOSE

The aim of this study was to retrospectively compare the fastball profiles of pitchers who had previously sustained grade I or II ulnar collateral ligament (UCL) injuries, were rehabilitated, and released back for competition with those of pitchers with no history of elbow injury.

METHODS

Eighteen pitchers from the pitching staff of 1 National Collegiate Athletic Association Division III team participated in this study. Group 1 had a history of grade I or II UCL injury (n = 8), and group 2 (n = 10) did not. A computerized pitch tracking device was used to analyze ball movement and pitching mechanics. The hypothesis was that the pitchers with a history of injury (group 1) would display differing fastball velocity-ball movement relationships compared to those without (group 2).

RESULTS

The groups had similar heights, weights, pitching experiences, and arm slot positions at ball release. The pitching coach-determined preinjury arm slot position and the postinjury computerized pitch tracking device measurements after return to competition displayed strong agreement (r = 0.83), suggesting comparable pre and postinjury pitching techniques. The groups had comparable glenohumeral joint range of motion and fastball profiles, except that group 1 released the ball at a 2.5 times lesser horizontal distance away from the pitching rubber center. Group 2 also displayed consistently more robust and more frequent fastball movement relationships with velocity, horizontal break, and vertical break than group 1.

CONCLUSIONS

Reduced horizontal ball release distances at comparable vertical ball release heights without changes in the arm slot position suggest that pitchers with a history of grade I or II UCL injury have greater contralateral trunk tilt and elbow flexion at ball release. Increased contralateral trunk tilt may occur to increase pitch velocity at the expense of ball movement while placing the pitching elbow in a potentially injurious position. Computerized fastball profile analysis using a computerized pitch tracking device, in conjunction with coach pitching technique observation, and team medical staff clinical examination may help better identify pitchers with an increased risk of UCL injury.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Current State of Data and Analytics Research in Baseball

PURPOSE OF REVIEW

Baseball has become one of the largest data-driven sports. In this review, we highlight the historical context of how big data and sabermetrics began to transform baseball, the current methods for data collection and analysis in baseball, and a look to the future including emerging technologies.

RECENT FINDINGS

Machine learning (ML), artificial intelligence (AI), and modern motion-analysis techniques have shown promise in predicting player performance and preventing injury. With the advent of the Health Injury Tracking System (HITS), numerous studies have been published which highlight the epidemiology and performance implications for specific injuries. Wearable technologies allow for the prospective collection of kinematic data to improve pitching mechanics and prevent injury. Data and analytics research has transcended baseball over time, and the future of this field remains bright.

Lead Foot Progression Angle in Baseball Pitchers: Implications to Ball Velocity and Upper-Extremity Joint Moments

The instant of foot contact is an important transition point during the pitch cycle between the linear portion of the pitch, as a pitcher strides down the mound and the rotational portion of the pitch. Understanding the implications of lead foot angle at foot contact is an essential information needed to assist pitching coaches in their work with individual pitchers. Therefore, the purpose of this study was to determine the association between lead foot progression angle at foot contact and ball velocity, elbow varus moment, and pelvic rotation. Kinematic and kinetic data were collected from 99 collegiate pitchers and analyzed using a random intercept, mixed-effects regression model. Significant associations were found between lead foot progression angle at foot contact and elbow varus moment (P = .004), as well as pelvic rotation throughout the pitching motion (P < .001). The data indicate that increased lead foot internal rotation at foot contact is associated with increases in the elbow varus moment but is not associated with ball velocity. This study provides scientific evidence that the rotational positioning of the lead foot can affect both pelvic motion and upper-extremity joint moments.

The Evidence Behind Weighted Ball Throwing Programs for the Baseball Player: Do They Work and Are They Safe?

PURPOSE OF REVIEW

Weighted baseball throwing programs have gained significant attention recently. They have been promoted as proven option for pitchers wishing to increase their throwing velocity and improve throwing mechanics. However, there is some concern that, if not applied properly, they may increase injury risk. In this review, we aim to (1) give a brief description of the potential mechanisms through with weighed ball programs that could improve throwing velocity, (2) summarize the available evidence regarding their effectiveness in increasing throwing velocity, (3) summarize the evidence on injury risk, and (4) propose directions for future studies.

RECENT FINDINGS

Initial research on weighted ball programs was published in the 1960s. Recently there has been an increase in research as interest from baseball organizations, instructors, players, and medical providers has grown. A recent randomized controlled trial demonstrated that pitching velocity can be increased through a 6-week weighted ball program; however, with that, they found that the rate of injury also increased. An earlier systematic review outlined 10 studies that evaluated weighted ball programs effect on pitching velocity and reported that 7 studies described increases in throwing velocity, while most studies did not comment on injury risk. They note that the results on rate of injury have been variable, likely secondary to the variability in time and intensity of different programs. The inconsistency in the methodology of weighted ball programs and studies has made it challenging to draw (scientifically) meaningful conclusions. Nevertheless, several studies have offered empirical evidence in support of the claim that weighted ball programs can increase pitching velocity through improved throwing mechanics. At the same time, these studies have emphasized the improvements in performance, while the potential effects on injury mechanisms have been less well understood. There is a need for improved standardization of these programs to allow for future study and subsequent modification to optimize performance.

The influence of trunk mechanics on the assessment of elbow position in college aged pitchers

Researchers have postulated that the rise in the incidence of pitching injuries is partially due to poor pitching mechanics. A topic that is often debated revolves around the correct positioning of the elbow in relationship to the body. Therefore, this study attempts to understand the associations of vertical or horizontal elbow positon with upper extremity joint moments, and ball velocity, and how elbow position is influenced by trunk position. Motion analysis data from 99 collegiate pitchers were analysed for this study. A random intercept, mixed-effects regression model was used to determine if statistically significant associations existed between elbow position and upper extremity joint moments and ball velocity. Results indicated that visual impressions of the elbow position were highly correlated with trunk position, whereas kinematic definitions of elbow position were correlated to the glenohumeral angle. Visual vertical and horizontal elbow position was associated with increased elbow varus moments (p = 0.001) and ball velocity (p = 0.019), respectively. Whereas kinematic elbow position was not associated with either upper extremity joint moments or ball velocity. Therefore, what coaches visually interpret as an improperly positioned elbow may actually be a combination of lateral lean, anterior tilt, and over rotation of the trunk.