Effects of a six-week weighted-implement throwing program on baseball pitching velocity, kinematics, arm stress, and arm range of motion

Usage and acceptability of data normalization in baseball pitching

In baseball pitching biomechanics, kinetic values are commonly ratio 'normalised' by dividing by mass or mass*height to allow for comparison between athletes of different sizes. However, creating a normalised ratio variable should meet certain statistical assumptions. Our purpose was to determine if elbow valgus torque predicted by pitching velocity is influenced by normalisation using regression model comparison with and without normalised torque values. Motion capture data for youth to professional pitchers (n = 1988) were retrospectively analysed. Normalisation assumptions were tested by comparing linear regression models to analogous models with an intercept fixed at zero and by examining remaining correlations between the confounding variable and new, normalised variable. Both mass (p < 0.001) and mass*height (p < 0.001) normalisation did not remove their respective relationship with torque. After accounting for mass or mass and height, velocity predicted 10% of variance in elbow valgus torque, whereas velocity predicted 59% of mass normalised torque and 45% of mass*height normalised torque. Ratio normalisation does not fully account for anthropometric variables that differ across pitchers and leads to different conclusions in the magnitude of velocity's predictive effect on elbow valgus torque. Therefore, we recommend using regression model comparison to account for anthropometric variables in baseball pitching kinetic data.

Most high school baseball pitchers are using weighted ball throwing programs to increase ball velocity: crosssectional analysis of US high school pitchers

Background

Weighted-ball velocity training programs are popular but may be associated with increased injury risk. The purpose of this study was to determine the current frequency of these programs, as well as their association with range of motion, strength, velocity, injury, and utilization in high school baseball pitchers.

Methods

This was a multicenter, prospective, community-based study including high schools from the Northeastern, Southeastern, Midwestern, and Western regions of the United States. Preseason pitchers were surveyed about their use of weighted ball velocity programs and history of injury. Preseason pitchers underwent standardized physical examinations and pitch velocity was measured. During a single high school season, pitch counts and injury incidence were prospectively collected.

Results

In total, 115 pitchers were recruited, of whom 63% had participated in a weighted ball program. There were no differences in range of motion or strength between groups who used weighted balls and those who did not. Pitchers that utilized weighted ball programs demonstrated a higher average fastball velocity (114.26 vs. 106.22 km/h [71 vs. 66 mph]; P < .001) as well as peak fastball velocity (115.87 vs. 109.44 km/h [72 vs. 68 mph]; P = .001) compared to those that did not use weighted ball programs. Pitchers that utilized weighted ball programs were no more likely to be single-sport athletes (44%) than those who were multisport athletes (49%, P = .667). Within the group who had used a weighted ball program 29% (13/45) reported a history of injury and within the group who had not used a weighted ball program 25% (10/40) reported a history of injury (P = .687). As only a single injury occurred in the entire cohort, comparison of injury rates could not be completed.

Conclusion

In this prospective study, the majority of high school pitchers reported using weighted ball programs to increase velocity, and these programs were associated with increased average and peak velocity compared to pitchers who did not use weighted ball programs. There were no significant differences in injury history between the 2 groups. Further study is necessary to understand the injury risk associated with weighted ball programs.

Weighted Baseball Training Affects Arm Speed Without Increasing Elbow and Shoulder Joint Kinetics

Long-term training effects of weighted ball throwing programs have been well documented. However, the mechanisms that facilitate these effects are poorly understood. The purpose of this study is to investigate within-session effects of throwing overload and underload baseballs to provide mechanistic evidence for weighted baseball training methods. Twenty-six collegiate- and professional-level baseball pitchers aged 20-30 years (mean age 23.5 [2.7] y) participated in a biomechanical evaluation while pitching a series of leather weighted baseballs. A 1-way repeated-measures analysis of variance was used to evaluate the intrasubject effect of ball weight on a total of 15 kinematic, kinetic, and performance parameters. Ball weight significantly affected pitch velocity, maximum elbow flexion, maximum pelvis rotation velocity, maximum shoulder internal rotation velocity, maximum elbow extension velocity, and anterior trunk tilt at ball release. None of the measured arm joint kinetics were significantly affected by ball weight. Training with 3- to 7-ounce (85- to 198-g) baseballs can be used to work on increasing pitching velocity without increasing throwing arm joint kinetics.

Does Velocity Increase From Flat-Ground to Mound Work During a Lighter Baseball Training Program?

INTRODUCTION

There has been recent interest in throwing from flat-ground versus the mound regarding stress on the elbow. Typical throwing progression programs begin with flat-ground work and progress to mound work.

METHODS

All baseball pitchers of ages 10 to 17 years who completed a 15-week pitching mechanics and velocity-training program were included. Players' pitch velocity was tested at four time points during training. Average velocity and maximum velocity of pitches from flat-ground were compared with those of mound, and change in velocity between testing sessions was also compared.

RESULTS

Thirty-six male pitchers (average age: 14.4 ± 1.6 years) were included. Fastball velocity increased by an average of 5.2 mph (95% confidence intervals 2.0 to 8.8 mph) at the end of the training program. When change in average and maximum velocity was compared between the four testing sessions, the most notable increase in velocity occurred between the third and fourth testing sessions. Both sessions were thrown from the mound.

CONCLUSION

The 15-week baseball pitcher-training program markedly improved pitching velocity. Throwing from a mound compared with flat-ground resulted in the largest velocity increase. Therefore, when attempting to increase a pitcher's velocity, throwing from the mound should be an integral part of any velocity program.

The Safety and Efficacy of Weighted Baseballs

One of the most common methods of training to enhance pitching velocity is the use of weighted baseballs. As with anything else, the excitement and popularity often proceed our scientific understanding. While there is still a lot to learn, our understanding of the science and efficacy of weighted baseball training has grown in recent years. The purpose of this clinical viewpoint is to summarize our current scientific understanding.

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.

Changes in Muscle Activity among College Pitchers Using 5- to 12-Oz Weighted Baseball

OBJECTIVES Several studies have reported that weighted baseball (WB) training is effective in improving ball speed; however, the weight of the ball suitable for training remains unclear. This study aimed to investigate the changes in muscle activity during pitching using 5- to12-oz WBs and to provide basic data for training programs to improve pitching speed.METHODS The subjects of this study were 10 overhand pitchers who had more than 5 years of experience. Muscle activity was measured and analyzed at 70–85% of throwing baseball maximum effort (TBME) during soft toss (ST) and TBME was evaluated using electromyography.RESULTS As the ball weight increased, muscle activity also increased in all pitching phases. Muscle activity was higher during ST with WBs heavier than 10 or 11oz than during TBME, indicating that the loads on the shoulder and elbow joint muscles increased. Conversely, muscle activity during ST with 5- to 7-oz WBs was lower than that during TBME, although phase and muscle group differences were observed.CONCLUSIONS The results of this study suggest that training with 8- to 10-oz WBs could increase muscle strength and activity, although the effect may vary with fitness level and muscle strength.

Training With Lighter Baseballs Increases Velocity Without Increasing the Injury Risk

Background:

Pitch velocity has become an increasingly popular metric by which pitchers are graded and compared. Training programs that utilize weighted balls have been effective in increasing velocity but at the cost of an increased injury risk. No studies have evaluated training with lighter baseballs with regard to increasing pitch velocity and the injury risk.

Purpose/Hypothesis:

The purpose of this study was to determine whether a training program utilizing lighter baseballs could increase fastball velocity without increasing the injury risk to participants. We hypothesized that a training program with lighter baseballs would increase fastball velocity but not increase the injury risk.

Study Design:

Case series; Level of evidence, 4.

Methods:

All baseball pitchers who participated in a 15-week program at a single location, with the same coaches, and aimed to improve pitching mechanics and increase velocity were included. The training program was broken down into 3 phases, and each participant went through the same program. Lighter baseballs (3 and 4 oz) and standard baseballs (5 oz) were utilized as part of the training program. Weighted (heavier) balls were not used. Velocity was measured at 4 time points throughout the program with the pitcher throwing 5 fastballs using a standard 5-oz ball at maximum velocity (sessions 3, 10, 17, and 25). Injuries for all players were recorded throughout the entire program.

Results:

A total of 44 male pitchers aged 10 to 17 years (mean age, 14.7 ± 1.8 years) completed the training program and were available for analysis. No pitcher sustained a shoulder or elbow injury during the course of the training program. Fastball velocity increased by a mean of 4.8 mph (95% CI, 4.0-5.6 mph) (P < .001). Overall, 43 of 44 players (98%) had an increase in fastball velocity over the course of the program.

Conclusion:

A 15-week pitching training program with lighter baseballs significantly improved pitching velocity without causing any injuries, specifically to the shoulder or elbow. Lighter baseballs should be considered as an alternative to weighted baseballs when attempting to increase a pitcher’s velocity.