A Case Study Exploring the Effects of a Novel Intra-Abdominal Pressure Belt on Fastball and Change-Up Velocity, Command, and Deception Among Collegiate Baseball Pitchers

Abstract

Baseball pitchers must reduce batters’ decision-making ability, locating pitches in zones where batters make weak contact. The purpose of this case study was to investigate potential pitching performance improvements when wearing a specialized intra-abdominal pressure (IAP) belt. Thirteen collegiate pitchers were randomly assigned to three bullpens of 40 pitches with visual encouragement from an integrated LED screen and a portable radar. Pitchers wore their typical belt, an IAP belt at regular length, and the IAP belt with a two-inch cinch for separate bullpen conditions. Fastball and change-up velocities, their average differences in velocity, and strike-throwing percentages were indexed and analyzed. A repeated measures ANOVA with an a priori of 0.05 and Tukey’s post hoc analyses evaluated significant differences amongst the case study population across pitch velocity, command, and deception, which was measured as the average velocity difference between fastballs and change-ups. Given the small sample size, subject-specific data were presented and showed the majority of pitchers threw faster, had greater accuracy, and displayed greater velocity ranges between fastballs and change-ups. The subject-specific results in this case study indicated that most pitchers improved performance across velocity, command, and deception metrics with the use of an intra-abdominal pressure belt designed to be worn in competition.

1. Introduction

Pitching performance is uniquely intertwined with disrupting decision-making for batters, which can lead to weaker contact and increased probability of making outs. There are two key metrics that qualify the value of a baseball pitcher and reflect their ability to neutralize batting performance, namely, the pitcher’s Fielding Independent Performance (FIP) and Wins Above Replacement (WAR) rating [1,2].When looking at these metrics, fastball velocity alone may not fully correlate with improvement. Equally important are a pitcher’s ability to maintain velocity differentials between fastballs and change-ups, and improved pitch tunneling. The latter is the visual deception that occurs when the same pitch is thrown, yet the ball branches off in different directions due to ball speed and spin characteristics, which move the ball to the bottom of the strike zone [2,3,4]. Another apex quality that becomes increasingly important as pitchers develop and move through competitive rankings is the ability to throw strikes; this is termed pitch command, which is the ability to locate pitches in the strike zone. Collectively, the ability to deceive batters and throw pitches to locations that induce lower exit velocities and distance off the bat, while achieving fewer walks and hit batsmen, all raise the potential of FIP and WAR success [1,2].

Previous research has indicated that players can compensate biomechanically in a variety of ways and still maintain throwing velocity for both the change-up (CH) and fastball (FB) [3,5]. Athletes were forced to alter their stride strategy and, despite such gross changes in force production and momentum, velocities were unchanged and grip strength reduced [3,6]. What is unknown are the overall fatigue effects throughout the season that elevate joint stress and the potential risks of modifying pitching mechanics or throwing programs over the long term, such as weighted ball velocity enhancement programming. The quest to throw at higher velocities is more compelling in today’s sport than at any other point in time. Generally, the selection criterion for high-level pitchers by Major League Baseball scouts is to identify amateur players who are at or above the current average velocity for the league, which motivates pitchers to engage in high-intensity velocity enhancement training [7,8,9]. Collegiate recruiting programs are following suit to motivate athletes to increase their throwing arm speed with “run and gun” deliveries without attention paid to accuracy, as athletes typically deliver the ball into a net or wall. It is believed that increasing arm speed with no emphasis on targeted throwing can alter the speed–accuracy trade off in commanding pitches; this can lead to greater accumulation of maximum effort pitches thrown, which can lead to more baserunners on base and reduce pitching success. Further, with increased pitch accumulation at maximum intent, pitchers elevate injury risk associated with overuse. This can be substantiated by previous research performed on velocity enhancement training, which showed 25% of the sample population terminated the study due to throwing arm injury [9].

Because of the injury risks associated with overuse at maximum throwing intensity, the need to improve the speed–accuracy trade off and the effect of velocity by altering speeds and added deception is warranted to improve not only performance, but also health, among competitive pitchers. Improved core function can improve consistency in the delivery, along with increased FB and CH pitching velocity and speed differentials, rotational deceleration, and co-contraction to stabilize the proximal body [10]. Elevated rotational trunk velocities have been shown to increase throwing velocity, while maintaining trunk position in the lateral plane can influence the medial release point position [11,12,13]. When the rotational control of the trunk impacts momentum exchange in combination with greater trunk lean, greater losses can be seen in functional forearm strength, which can lead to a loss of dynamic stability for the medial elbow, thereby raising Tommy John Surgery risks [6,12,14].

One way to improve trunk control is with more responsive core engagement, as seen through dynamic neuromuscular stabilization training, which is intimately tied to intra-abdominal pressure (IAP), to improve energy transfer, proximal stability, and distal segment joint power [10]. In connection with the positive performance contribution made by increased IAP, which can amplify throwing arm power and command and lessen medial elbow torque and forearm strength loss, a novel baseball belt has been innovated to heighten such effects in competition. The noted improvement in this case study shows that the IAP can offer a safe alternative to weighted ball training, raise the competitiveness and durability for baseball pitchers, and reduce the associated risks, e.g., current epidemiologic findings state that 5% of all pitchers will experience a throwing arm surgery [15]. High pitch totals can lead to overuse risk. A clear gap in the literature exists as it relates to the speed–accuracy tradeoff influenced by increased IAP and proximal core control that forms the basis of this case study. Therefore, the purpose of this study was to examine the pitching velocity, deception, and command impacts of wearing a baseball belt designed to increase IAP among high-level pitchers. It was hypothesized that improved dynamic stability offered through a baseball belt designed to raise IAP will increase fastball and change-up velocity, and increase the speed differential between pitches, while heightening accuracy, versus traditional belt wear in baseball.

2. Methods

Thirteen collegiate pitchers (height; 1.86 ± 0.06 m, weight; 88.5 ± 8.31 kg, age; 20.6 ± 1.39 years) signed an informed consent form to participate in this research study, which was approved by the Institutional Review Board at Arizona Christian University (IRB 21CFR56.108).

Pitchers went through a standardized lower-body dynamic warm-up routine before performing a self-selected throwing warm-up to ready the arm for competitive effort. Bullpens designed to encourage effort in competitive play were fully randomized across three conditions, with two conditions involving a specialized IAP belt (Core Technology Inc, Avon, OH, USA): (1) pitchers wearing their regular belt (REGB), (2) pitchers wearing the specialized IAP belt at regular belt length (IAPB), and (3) pitchers wearing the specialized IAP belt with a 2-inch cinch (IAP2) to create a maximum restraint. The IAP belt used in this study was interwoven and stretch-resistant, maintaining a 5 mm thickness compared to typical baseball belts, which are 1 mm in thickness. Both IAP and regular belts are worn across the waistline and can accommodate a variety of waist circumferences. Belts are secured by belt loops in baseball pants. However, the IAP is cut to the proximal body specification of the athlete by first measuring the athlete’s waist circumference while in baseball pants to maintain the integrity and thickness of the belt in supporting the core region. The individual size specification promotes greater support when wearing baseball pants in raising IAP through co-contraction of the proximal muscles; this co-contraction can be elevated with cinching. In total, pitchers threw 159 pitches, including pre-inning warm-up pitches, spanning three bullpen sessions of 40 pitches that involved two innings of 20 pitches thrown in a sequence of 2 fastballs to 1 change up. Intermittent rest periods between pitches were set at 15 s, with a 5 min break between innings. To encourage high-level effort and competitive pressure, a handheld radar gun unit (Santa Rosa, CA, USA), capable of capturing velocities up to 130 mph, was integrated with an LED screen, which provided visual encouragement to throw at maximum intensity (Pocket Radar, Santa Rosa, CA, USA). A professional catcher indicated balls and strikes, which were confirmed on each pitch by the Principal Investigator prior to being analyzed. A minimum of 72 h rest was provided between bullpen sessions. Figure 1 illustrates the testing conditions for each simulated bullpen.

Performance Analyses

Following testing sessions, all velocity and command data were manually entered into a spreadsheet to evaluate subject-specific analyses for performance tendencies in fastball and change-up velocities, command, and deception, which was calculated as the velocity difference between fastballs and change-up pitches. Data were aggregated in CSV format in Microsoft Excel (Redmond, WA, USA) and evaluated for subject-specific performance, as determined by the percentage of subjects experiencing benefit with the IAP belt.

3. Results

The exploratory case study revealed a positive individual effect on throwing arm strength when examining subject-specific responses, which can be seen in

Table 1. Subject-specific data indicating fastball velocity differences between belt conditions.

Player ID	REGB Avg (MPH)	IAPB Avg (MPH)	IAP2 Avg (MPH)
1	86.7	87.4	87.7
2	75.7	74.7	75.5
3	79.3	78.3	78.1
4	85.4	85.5	83.3
5	84.3	84.1	86.1
6	81.0	80.1	80.4
7	85.5	85.2	84.1
8	76.7	78.6	77.1
9	81.6	81.7	80.8
10	84.0	82.8	82.9
11	84.0	84.1	84.5
12	84.4	83.7	82.1
13	85.1	84.7	85.3

,

Table 2. Subject-specific data indicating change-up velocity differences between belt conditions.

Player ID	REGB Avg (MPH)	IAPB Avg (MPH)	IAP2 Avg (MPH)
1	80.8	79.5	80.6
2	69.1	67.6	69.0
3	70.4	70.8	68.8
4	77.3	76.7	75.2
5	73.1	74.2	74.8
6	71.4	70.8	70.7
7	74.3	75.2	74.9
8	70.8	73.3	72.0
9	74.0	74.1	74.2
10	73.4	73.1	73.9
11	74.0	73.9	72.8
12	79.6	78.1	77.8
13	81.0	81.8	82.2

,

Table 3. Subject-specific data indicating fastball command differences between belt conditions.

Player ID	REGB Avg (K%)	IAPB Avg (K%)	IAP2 Avg (K%)
1	66.7	69.2	68.0
2	68.0	66.7	38.5
3	55.6	55.6	63.0
4	63.0	51.9	66.7
5	61.5	73.1	51.9
6	59.3	55.6	55.6
7	48.1	59.3	74.1
8	63.0	63.0	59.3
9	77.8	88.9	63.0
10	84.6	81.5	66.7
11	74.1	59.3	40.7
12	38.5	57.7	44.4
13	70.4	63.0	66.7

,

Table 4. Subject-specific change-up command differences between belt conditions.

Player ID	REGB Avg (K%)	IAPB Avg (K%)	IAP2 Avg (K%)
1	50.0	23.1	33.3
2	46.2	46.2	41.7
3	46.2	23.1	30.8
4	30.8	46.2	76.9
5	30.8	38.5	46.2
6	61.5	23.1	61.5
7	84.6	46.2	61.5
8	53.8	38.5	53.8
9	61.5	69.2	30.8
10	53.8	76.9	53.8
11	38.5	38.5	69.2
12	38.5	53.8	38.5
13	30.8	46.2	38.5

and

Table 5. Subject-specific differences in fastball-change velocity ranges between belt conditions.

Player ID	REGB Avg (MPH ∆)	IAPB Avg (MPH ∆)	IAP2 Avg (MPH ∆)
1	5.9	7.9	7.1
2	6.6	7.1	6.5
3	8.9	7.5	9.3
4	8.1	8.8	8.1
5	11.2	9.9	11.3
6	9.6	9.3	9.7
7	11.2	10.0	9.2
8	5.9	5.3	5.1
9	7.6	7.6	6.6
10	10.6	9.7	9.0
11	10.0	10.2	11.7
12	4.8	5.6	4.3
13	4.1	2.9	3.1

. Each table represents the performance data associated with each belt condition and the percentage of athletes who had seen performance enhancement with use of the IAP belt.

Maximum fastball velocity for each subject in association with each belt condition. Bolded numbers indicate subjects’ highest average velocity values across belt conditions. As shown, approximately 54% of subjects indicated greater fastball velocity using an intra-abdominal pressure belt, yet parametric statistics did not show statistically significant findings in relation to overall group means due to the case study sample being under-powered. Belt groups: Regular IAP Belt; IAPB, 2-Inch Cinch IAP Belt; IAP2, and Regular Belt; REGB.

Maximum change-up velocity for each subject in association with each belt condition. Bolded numbers indicate subjects’ highest average velocity values across belt conditions. As shown, approximately 54% of subjects indicated greater change-up velocity using an intra-abdominal pressure belt, yet parametric statistics did not show statistically significant findings in relation to overall group means due to the case study sample being under-powered. Belt groups: Regular IAP Belt; IAPB, 2-Inch Cinch IAP Belt; IAP2, and Regular Belt; REGB.

Average fastball command for each subject in association with each belt condition. Bolded numbers indicate subjects’ highest average strike-throwing percentages (K%) across belt conditions. As shown, approximately 62% of subjects indicated greater fastball command using an intra-abdominal pressure belt, yet parametric statistics did not show statistically significant findings in relation to overall group means due to the case study sample being under-powered. Belt groups: Regular IAP Belt; IAPB, 2-Inch Cinch IAP Belt; IAP2, and Regular Belt; REGB.

Average change-up command for each subject in association with each belt condition. Bolded numbers indicate subjects’ highest average strike-throwing percentages (K%) across belt conditions. As shown, approximately 70% of subjects indicated greater fastball command (two excluded due to ties) using an intra-abdominal pressure belt, yet parametric statistics did not show statistically significant findings in relation to overall group means due to the case study sample being under-powered. Belt groups: Regular IAP Belt; IAPB, 2-Inch Cinch IAP Belt; IAP2, and Regular Belt; REGB

Average velocity differences between fastball and change-up pitches for each subject in association with each belt condition. Bolded numbers indicate subjects’ highest level of deception as determined by greater average velocity differences (MPH ∆) across belt conditions. As shown, approximately 70% of subjects demonstrated greater deception, indicated by greater velocity differences between the fastball and change-up using an intra-abdominal pressure belt, yet parametric statistics did not show statistically significant findings in relation to overall group means due to the case study sample being under-powered. Belt groups: Regular IAP Belt; IAPB, 2-Inch Cinch IAP Belt; IAP2, and Regular Belt; REGB

4. Discussion

Baseball high-performance training has a spectrum of approaches for evaluating risk and rewards. As this relates to velocity enhancement training, several studies have indicated the increased loading risks associated with maximum-effort throwing, running at high speed, blocking the lead leg, and throwing as hard as possible into a wall or net [8,9,16]. Risk multiplies when throwing balls that are underweight, as throwing arm acceleration increases, and with larger players, the force potential can be greater than what they experience when pitching on a mound [8].

Major League Baseball has written numerous articles on the injury risks associated with the inception of the pitch clock, yet a consensus has been voiced by the readership and athletes alike that velocity enhancement training and the desire to throw at more than 100 mph are the culprits [17,18]. The conundrum of increased throwing-velocity performance with paralleled risk requires innovation in delivering methods and products to simultaneously maximize performance and health.

In this study, an IAP belt was introduced as a potential tool to raise and maintain velocity, establish more consistency, and add deception by establishing large differences in pitching speeds between pitchers’ fastballs and change-ups. Our hypothesis was supported on a subject-specific level, as this case study presented greater benefits to velocity, command, and deception attributed to IAP belt use on a subject-specific level. One main postulate is that with increased IAP, the majority of pitchers were able to execute greater dynamic neuromuscular control to brace the lead leg, maintain trunk position, and sustain high throwing arm accelerations.

Dynamic neuromuscular control involves the execution of co-contracted bracing strategies in sport, and requires activating the diaphragm, intrinsic core musculature, and paraspinal muscle groups at the same time as increasing IAP in the abdominal cavity [10]. This coordinated bracing contraction adds to spinal column stiffness through rotation and is further augmented by compression of the stomach, an internal bladder, being held against the spine [10]. When it comes to trunk control, contralateral fascial lines are highly important for rotational athletes, as muscles and fascia are aligned in an “X” pattern and have been likened to a serape, an indigenous scarf that wraps around the body and forms a figure-eight pattern [19]. In essence, to increase rotational speed of the trunk, the athlete must optimize stretch-shortening responses between the lead hip and throwing shoulder [19]. Hip–shoulder separation between these two anatomical points is highly impacted by lead leg bracing and the rhomboids and posterior muscles of the throwing shoulder, as energy is transferred from the pelvis bi-directionally, going upward into the trunk and downward into the lead leg [19,20]. During the turn and to the terminal end-point of ball release, intra-abdominal pressure develops and rises sharply to the point of the highest shoulder compressive loads just after the ball leaves the hands, and therefore, athletes who can sustain highly responsive proximal bracing are likely to achieve consistent lower-body kinematics and ground reaction force applications, and reduce overloading the shoulder in its most vulnerable position at release [10,21].

Throwing athletes who have better dynamic stability tend to throw harder in overhand sport and are healthier [22]. This has been demonstrated in pitchers who display unilateral hip and lower-limb strength, an intersegmental interaction that is linked to athletes’ proximal bracing capability [22,23,24,25]. As an analogy, a dynamic bracing strategy for the proximal chain in the pitching delivery is like cracking a whip. Intersegmental energy transfer hits an abrupt stopping point to generate as much speed as possible to the endpoint of the whip, which is analogous to the throwing hand in the kinetic chain [26]. Heightened IAP accelerates the whiplike action of throwing through optimizing momentum exchanges and maximizes the potential of the stretch-shortening cycle between maximum hip–shoulder separation between the lead hip and throwing shoulder [19,27,28]. As a result, it is possible to achieve higher throwing velocities with better trunk stability, and pitchers who maintain trunk positions that allow the shoulder to maintain a consistent release point can minimize elevations in elbow varus torque, a measure of medial elbow loading that can increase ulnar collateral ligament stress [12,13,14,22,29].

The theoretical mechanism for the IAP belt involved in this study is that the design furthers the bracing capacity for the athlete by providing a retaining wall for muscles to push into while the belt pushes back on the muscles to heighten the IAP. In a sense, this interaction between the external support of the IAP belt and intrinsic muscles is like wearing a powerlifting weight belt. Long-term health benefits arising from heightened IAP in powerlifting creates a potential parallel for IAP baseball belts, as powerlifters have been shown to have greater muscular power with minimal elevations in neuromuscular recruitment effort in barbell squatting [30]. Perhaps similar neuromuscular recruitment efficiency can be seen in rotational athletes such as baseball pitchers and hitters, thereby reducing overuse injury risks from managing muscular fatigue in the core region of the body, by maintaining paraspinal and oblique activation with gains in explosive rotational power [30]. As an extreme, the IAP belt was cinched two inches shorter than the pitchers’ regular belt length and may have better regulated muscular recruitment efforts in stabilizing the proximal body to produce high velocities.

From the subject-specific data, the majority of pitchers in this study benefited from an IAP baseball belt versus their typical belt. The IAP belt allowed them to throw both their fastballs and change-ups at higher velocities, throw all pitches more accurately, and increase the velocity range between the fastball and change-up, which collectively would alter hitters’ timing in recognizing pitches and coordinating a high-impact swing. Future work is needed to determine how altered bi-directional energy transfer in bracing from the pelvis, a direct result of less effective proximal stiffness, has the potential to be improved with a baseball belt designed to raise IAP. It was found that both extreme tightening and the regular belt length with the IAP belt provided individual benefits. Future work should emphasize a larger sample size and explore each individual belt setting to determine an optimum for IAP that aims to achieve improved subject-specific responses across velocity, command, and deception, as well as biomechanics looking at power dynamics.

5. Limitations

On a subject-specific level, this study indicated velocity, command, and deception benefits of wearing a specialized baseball belt designed to increase IAP. However, one must consider a few important limitations of this work in the interpretation of this case study’s results. This case study was exploratory in nature, as this work was the first to explore an IAP apparatus that is functional in competitive settings and lacked the statistical power to determine the main effects between conditions. Future work should consider a larger-scale statistically powered investigation that can look at incremental changes in IAP through an incremental design, with the belt worn over multiple simulated bullpens to evaluate sustainable performance (minimal losses in velocity, command, and deception).

Outside covariates also proposed challenges in arriving at statistically significant group mean differences. Future research endeavors should incorporate controlled training regimens for athletes to mitigate the confounding effects of variable training schedules on the study outcomes. As a result, athletes in this study had varying workload and training schedules, which could have either undertrained or overtrained the athlete leading into the competitive bullpen simulations. A more stringent research design could have controlled for these confounders if implemented outside of the scholastic year, as athletes have greater control of their training and throwing programming. The study design did its best to encourage adrenaline; however, like other laboratory studies, the absence of real game conditions may have lowered contractile effort and could have produced differing results in actual game play. Given the stated limitations, this case study created a new avenue to evaluate velocity enhancement approaches that stabilize the speed–accuracy trade off (as speed increases, accuracy decreases) without the injury risks associated with throwing weighted baseballs to increase throwing arm acceleration and range of motion. As a result, increasing IAP in the pitching delivery with a specialized belt provides an opportunity to study a player-development technology that increases both performance and durability for competitive pitchers. Lastly, it is advisable to undertake long-term tracking studies to evaluate the prolonged use of the IAP belt and its effects on both the performance and health over extended periods to ensure longstanding efficacy for baseball players.

6. Conclusions

This exploratory case study found that a greater percentage of subjects wearing the intra-abdominal pressure belt saw an increase in throwing velocity, accuracy, and deception in bullpens that simulated competition. With further research, incremental tightening of the intra-abdominal pressure belt could identify optimal settings for each player to improve core engagement and proximal stiffness, with improved statistical performance.