Correlation between Strength, Size, Bat Speed and Performance in High School Hitters

Study Overview

Objective

• To investigate the relationships between muscle strength, swing speed, batting statistics, and body composition in high school baseball players.

Participants

• 29 high school male baseball players, aged approximately 15.9 years, assessed in July 2022.

Methodology

Data Collection

• Measurements included body composition (body fat percentage, lean body mass [LBM], fat mass index [FMI], fat-free mass index [FFMI]), muscle strength (bench press, squat, deadlift), batting statistics (batting average, on-base percentage, slugging percentage, on-base plus slugging), and swing speed.
• Used a bioelectrical impedance analyzer for body composition assessments.

  

Statistical Analysis

•   Employed Pearson’s and Spearman’s correlation coefficients to analyze relationships.
•   Conducted multivariate regression analyses to identify significant predictors.

Key Findings

Muscle Strength Correlations

•   LBM was a significant predictor of bench press and swing speed.
•   FFMI was a significant predictor for squat performance.
•   FMI was associated with deadlift performance.

Swing Speed and Batting Statistics

•   Significant correlations were found between swing speed and LBM, as well as FFMI.
•   No significant associations were detected between body composition parameters and batting statistics, suggesting that technical skills may be more critical for batting performance.

Discussion Points

Importance of Body Composition

• Lean body mass is crucial for enhancing swing speed, indicating the need for effective body composition management in training regimens.
• Despite the correlations with swing speed, body composition did not correlate with batting statistics, highlighting the multifactorial nature of batting performance.

Technical Skills Emphasis 

• The study recommends prioritizing technical skills over purely physical attributes to improve batting statistics in players.
• Factors like mental state, game situation, and pitcher skill also influence batting outcomes.

Limitations

Sample Size and Selection Bias

•   The study's focus on a single team may limit the generalizability of the findings.
•   Differences in training and coaching approaches across teams could affect results.

Temporal Changes

• Body composition and performance metrics may vary throughout the season, complicating the attribution of performance outcomes to specific variables.

Measurement Methods

• The use of cost-effective bioelectrical impedance analyzers may lead to less accurate results compared to more advanced methods.

Practical Applications

Training Recommendations

• Coaches should integrate body composition management strategies to enhance muscle strength and swing speed.
• Focus on developing batting mechanics, timing, and adaptability to improve overall batting performance.

This research provides valuable insights for coaches and players, emphasizing the balance between physical conditioning and skill development in high school baseball.

Full article:

Correlation Between Muscle Strength, Swing Speed, Batting Statistics, and Body Composition Parameters in High School Baseball Players: A Retrospective Observational Study

Suzuki, K., Mizoguchi, Y., Kimura, F., Fujisaki, K., Yokoyama, D., Hall, T., & Akasaka, K. (2022). Correlation Between Muscle Strength, Swing Speed, Batting Statistics, and Body Composition Parameters in High School Baseball Players: A Retrospective Observational Study. The Journal of Strength & Conditioning Research, 10-1519.

Understanding torso rotation in skilled vs novice hitters

Differences in trunk rotation during baseball batting between skilled players and unskilled novices

Nakata, H., Miura, A., Yoshie, M., Higuchi, T., & Kudo, K. (2014). Differences in trunk rotation during baseball batting between skilled players and unskilled novices. The Journal of Physical Fitness and Sports Medicine, 3(4), 457-466.

Article link

Instagram: @hittingresearch

Summary

The study published in J Phys Fitness Sports Med investigates differences in trunk rotation patterns during baseball batting between skilled players and unskilled novices.

• The research involved eight skilled collegiate-level players and nine unskilled novices.
• High-speed video cameras were used to capture the batting motions, focusing on maximum angles during backswing, impact angles, and angular displacements during the forward swing.

 
Key objectives of the study included:

•   Analyzing how upper torso and pelvis rotate during batting.
•   Determining when maximum angles are achieved during the backswing.
•   Examining trunk rotational patterns between skilled and unskilled individuals.

The methodology included:

•   Subjects performed 45 batting swings under controlled conditions.
•   A consistent experimenter threw the ball to mimic live pitching.
•   Reflective markers were attached to the subjects to capture motion data, with a focus on four key markers on the shoulders and hips.

Aspects analyzed:

• Movements were observed to clarify upper torso, pelvis, and torso-pelvis interaction angles during the batting motion.
• Timing and variability of movements were evaluated over multiple trials.

Findings revealed significant differences in angular displacements:

•   Skilled players exhibited larger trunk rotations compared to unskilled novices.
•   Maximum upper torso angles during backswing were -13.0° for skilled players compared to -14.6° for novices.
•  The pelvis angles during backswing were –7.4° for skilled players versus -4.1° for novices.

Angular displacement during the forward swing also differed:

•   Skilled players had an upper torso rotation of 126.1° compared to 79.5° for novices.
•   Pelvis rotations were 99.6° for skilled players and 61.0° for novices.
•   Timing of the maximum angle during backswing was notably later in skilled players:
•   Maximum pelvis angle timing was later in skilled players (392 ms) compared to unskilled novices (518 ms).

Movement variability was a key finding:

•   - Skilled players displayed greater precision in their angular displacements than unskilled novices.
•   - Variability in angular displacement during the forward swing indicated more stable motion among skilled players.

Insights on angular velocity:

•   Peak angular velocities were significantly higher in skilled players, measuring 984°/s for the upper torso compared to only 587°/s in unskilled novices.
•   Movement variability in peak angular velocity was similar between the groups, suggesting uniform performance stability.

The study also evaluated the importance of the kinetic chain in efficient energy transfer during batting:

•  An effective transfer of kinetic energy from lower limbs to upper body was linked to improved batting performance.
•  Novices displayed less effective energy transfer, resulting in diminished swing efficacy.

The role of movement accuracy was considered:

•  Unskilled players might sacrifice swing speed to maintain accuracy in bat-ball contact, reflecting a common speed-accuracy trade-off in motor behavior.
•   Higher movement variability in novices suggested less stable swings and poorer mechanics.

Practical implications for training:

•  Results highlight the necessity for training to emphasize angular displacement and velocity of the trunk during batting.
•  Coaches should focus on helping junior players and novices develop effective trunk rotation techniques to enhance swing mechanics.

Study limitations included:

•   Potential variations in impact points due to the nature of the ball delivery affecting motion data.
•   Lack of direct measurement of muscle power, which could further differentiate skilled from unskilled performers.

Future research directions:

•   The study suggests further exploration into how different swing techniques and physical conditioning affect overall batting performance.
•   An analysis incorporating all relevant body markers from skilled players could illuminate additional contributors to effective batting mechanics.

Overall conclusions highlight:

•   Trunk rotation and movement efficiency are key components in successful baseball batting.
•   Understanding these dynamics can significantly benefit training methodologies for novice and junior players aiming to improve their hitting skills.

Clench your jaw for more bat speed?

The Effects of Concurrent Activation Potentiation on Bat Swing Velocity of Division II College Softball Athletes

Mace, A. P., & Allen, C. R. (2020). The effects of concurrent activation potentiation on bat swing velocity of division II college softball athletes. International Journal of Exercise Science, 13(1), 1630.

This study investigated the effects of concurrent activation potentiation (CAP) on bat swing velocity (BSV) in Division II college softball athletes, employing a Zepp sensor to measure the swing's velocity. Thirteen female athletes performed swings using two conditions: with maximal jaw clenching and with relaxed jaw muscles. The Zepp sensor recorded a mean swing velocity of 28.02 m/s (62.68 mph) in the relaxed condition compared to 29.42 m/s (65.82 mph) during the jaw clenching condition, revealing a statistically significant increase of 1.4 m/s (3.14 mph) (p = 0.003). This study demonstrated that maximal jaw clenching effectively enhances BSV, suggesting that athletes may improve their hitting performance through this simple yet impactful technique. Importantly, individual variations in response to the jaw clenching strategy were noted, with ten out of thirteen participants showing improved BSV, highlighting the necessity for athletes to experiment with RVC methods suitable for their unique performance needs. These findings underscore the potential of CAP as a practical ergogenic strategy that can be easily adopted in training for enhanced athletic outcomes across various sports requiring powerful swings.

Article Link

Lower extremity kinematic and kinetic factors associated with bat speed at ball contact during the baseball swing

Lower extremity kinematic and kinetic factors associated with bat speed at ball contact during the baseball swing 

Orishimo, K. F., Kremenic, I. J., Modica Jr, E., Fukunaga, T., McHugh, M. P., & Bharam, S. (2023). Lower extremity kinematic and kinetic factors associated with bat speed at ball contact during the baseball swing. Sports Biomechanics, 1-12.

Summary:

The study examined the biomechanical factors influencing bat speed during a baseball swing in collegiate players. Researchers aimed to identify which kinematic (movement-based) and kinetic (force-based) variables correlate with the linear bat speed at the moment of ball contact. By analyzing the swings of 20 players as they hit from a tee, they recorded motion via a capture system and measured ground reaction forces using force plates. The average bat speed was noted at 30 m/s, with significant correlations found between bat speed and various ground reaction forces generated by the lead foot. 

Specifically, the peak vertical ground reaction force showed a strong relationship (r = 0.622, P = 0.001) with bat speed, as did the peak anterior/posterior force and resultant force. The authors highlighted the lead leg's critical role in generating and transferring force through the kinetic chain, emphasizing that effective training should focus on enhancing lower extremity strength and sport-specific mechanics. Kinematic factors, including peak pelvis and trunk velocities and hip-shoulder separation, showed negligible correlations to bat speed, indicating that ground forces are more decisive than segmental velocities in this context. 

The timing of various kinematic and kinetic events was analyzed, revealing that key moments such as peak lead knee extension and hip-shoulder separation occurred significantly earlier than peak forces generated, thus establishing a sequence critical for optimizing hitting performance. The authors suggest incorporating closed kinetic chain exercises in training, such as squats and specific hitting drills, aiming to improve lower extremity kinetics. Future studies are encouraged to explore how such training impacts bat speed and mechanical performance during swings. While the study’s findings may guide coaches and players to enhance batting skills, limitations were noted, including the exclusive focus on collegiate players and the use of a tee instead of live pitching, which could affect the generalizability of the results. Overall, the research provides valuable insights into optimizing bat speed through biomechanical factors.

Article link

Strength and Conditioning Programs to Increase Bat Swing Velocity for Collegiate Baseball Players

Strength and Conditioning Programs to Increase Bat Swing Velocity for Collegiate Baseball Players

Haruna, R., Doi, T., Habu, D., Yasumoto, S., & Hongu, N. (2023). Strength and conditioning programs to increase bat swing velocity for collegiate baseball players. Sports, 11(10), 202.

Summary:

The study by Haruna et al. (2023) delves into the relationship between anthropometric and physiological variables related to bat swing velocity (BSV) among collegiate baseball players. It emphasizes that a higher BSV, crucial for hitting performance, correlates positively with various factors, notably body mass and muscle strength. The research involved 78 male collegiate players, assessing their height, body mass, and lean body mass, along with grip and back muscle strength, sprinting ability, and explosive power via standing long jumps and medicine ball throws. Results showed significant correlations between BSV and physical performance variables, particularly upper and lower body strength. Specifically, lean body mass and back muscle strength emerged as the most significant predictors of increased BSV. 

The study also categorized players into three performance levels based on BSV—Fast, Middle, and Slow—highlighting that those in the Fast BSV group exhibited superior body characteristics and muscle strength compared to their counterparts. It advocates for tailored strength and conditioning programs that focus on improving muscle strength and body conditioning to enhance BSV. 

The authors propose integrating baseball-specific training into broader strength training regimens, including exercises such as the hang power clean and dynamic bat swing training, to optimize players’ performance. Additionally, they underline the importance of individualized training strategies tailored to each player's physical profile. 

While the research presents robust findings and implications for training, it acknowledges limitations, such as the inability to definitively establish causation due to weak correlation coefficients and a limited sample size. The study calls for longitudinal research to better understand BSV determinants and their effects on overall baseball performance, particularly in relation to batting averages. This comprehensive analysis sheds light on the essential link between physical conditioning and batting capabilities, serving as a guide for coaches and trainers in optimizing player development in collegiate baseball.

Article link

Torso rotational strength contributes to bat speed

The positive correlation between trunk, leg, and shoulder strength and linear bat velocity at different ball locations during the baseball swing in adult baseball hitters

    The study examines the correlation between trunk, leg, and shoulder strength and bat velocity in adult baseball hitters, particularly considering different ball locations within the strike zone. The researchers aimed to identify how various muscle strengths contribute to bat speed and which segment's strength serves as the best predictor for this speed. Nineteen male amateur and collegiate baseball players participated in the study, where they were tested for isokinetic strength and bat velocity at five specific ball locations: middle, high inside, high outside, low inside, and low outside. The findings revealed significant positive correlations between trunk rotation strength and bat velocity across all positions. 

    Although knee strength also showed correlations at most locations, shoulder strength was only significant for outside pitches. Through multiple regression analysis, trunk rotation strength emerged as the sole significant predictor of bat velocity regardless of the ball's position. The average bat velocities recorded were comparable to published studies, emphasizing the importance of trunk strength in baseball swings. 

    Additionally, the stronger the hitter's trunk rotation, the higher the bat velocity achieved, underscoring its critical role in generating force rapidly. Lead knee extension strength also correlated positively with bat velocity for several positions, indicating its role in stabilizing the pelvis and facilitating energy transfer. However, the correlation with shoulder strength was limited, only observed with outside pitches, suggesting that this segment might be more crucial when the hitter reaches for pitches away from the body. 

    The study concludes that enhancing trunk rotation strength could benefit hitters looking to improve bat velocity, although peripheral muscle groups, despite not being significant predictors, remain essential for overall swing mechanics. The results indicate that further research is needed to explore other contributing factors, especially for pitches inside the strike zone, where strength alone may not fully explain swing outcomes. Overall, the insights from this study emphasize targeted physical training to develop specific muscle groups for improved baseball performance.

Citation:

Chu, Y., Keenan, K., Allison, K., Lephart, S., & Sell, T. (2015). The positive correlation between trunk, leg, and shoulder strength and linear bat velocity at different ball locations during the baseball swing in adult baseball hitters. Isokinetics and exercise science, 23(4), 237-244.

Link to study

Strength and Conditioning Programs to Increase Bat Speed in College Players

Bullets from the study:

• Greater strength, power, lean body mass = higher bat speed

• All anthropometric variables(height, mass) were associated with bat speed

• 3 performance variable had weak statistically significant association with bat speed 

• Baseball specific training APPLIES power to swing - power+coordination+timing

• The average bat speed for this college group was 65.37 mph with a range of 56.23 to 76.6

• The authors provide suggests for each group of players based on their results

Summary

"Strength and Conditioning Programs to Increase Bat Swing Velocity for Collegiate Baseball Players" investigates the anthropometric and physiological variables associated with bat swing velocity (BSV) and explores strength and conditioning programs to increase BSV in collegiate baseball players. The study involves 78 male collegiate baseball players, and various measurements were taken including BSV, anthropometric measurements (height, body mass, lean body mass), grip strength, back muscle strength, standing long jump, and backward overhead medicine ball throwing. The results show that BSV is correlated with anthropometric and physiological variables, particularly upper and lower body strength and full-body explosive power. The study suggests that strength and conditioning coaches may consider using this information when designing training programs for collegiate baseball players.

Subjects were divided into 3 groups (fast, middle, slow) based on performance.  The table above shows the difference in characteristics between groups.

Solid description of baseball-specific training from this study.  Baseball specific training APPLIES power to the swing and includes both coordination and timing.

Link to article

Haruna, R., Doi, T., Habu, D., Yasumoto, S., & Hongu, N. (2023). Strength and Conditioning Programs to Increase Bat Swing Velocity for Collegiate Baseball Players. Sports, 11(10), 202.

Comparison of baseball swing biomechanics between different age and competition levels

Kinematic comparison among difference age groups compared the hitting mechanics of players from different levels.  Little league, high school, division 1 2 and 3, minor league and major league players did a biomechanics motion capture while batting off a tee.  This video summarizes the research study and the differences between the players with some practical coaching applications.

A few take always for me were:

1. Prevalence of excessive back shoulder aDDuction in youth.  Aka long swing or bat drag, this is when the back elbow is lower and closer to the midline of the body.  Also typically an indication of mis-alignment or inability to effectively rotate the torso.
2. Youth segment speeds can rotate just as fast as older players.  Hips, in this instance, rotated faster for youth than higher levels.
3. Learning to TRANSFER energy from one segment to the next is just as important as developing rotational speed.  This could be addressed with either strength/stability OR timing/technique improvements.
4. Start teaching kids to move better when they are young!

References:

Dowling, B., & Fleisig, G. S. (2016). Kinematic comparison of baseball batting off of a tee among various competition levels. Sports biomechanics, 15(3), 255-269.

Optimizing Swing Sequence Phases for Bat Speed, Power and Contact

The title of this research paper, published in 2020,  is “Sequential order of swing phase initiation in baseball” By lead author Ethan Stewart, now the lead sports scientist for the Oakland A’s. 

Core Training Program Improves Exit Velocity in High School Baseball Players

Straightforward here…

Rotational training program for HS baseball players improved batted ball exit velocity (measured off batting tee) by statistically significant 3.1 mph but did NOT improve throwing velocity

• 24 high school baseball players (age 14-18) were randomly split into 2 groups - control and rotational training (RT).  
• Both groups did the same baseball practice twice per week for 2-hours each practice.
• The RT group did an additional 1-hour session after school 2x/week for 6 weeks. 
• The RT program consisted of several exercises (see image below) with weighted walks loaded ~50% bodyweight for ~27m and ~1-3 sets of ~8-20 reps (details in the article linked at bottom of page).

Summary:

This paper investigates the effects of core training on high school baseball performance. The study aimed to explore the effectiveness of a resistance training program targeting the muscles of the core in order to increase force production in torsional movements such as throwing and hitting in baseball. The study involved 24 male high school baseball players who were randomly assigned to either a control group or a core training group. The control group attended baseball-specific workouts twice a week for six weeks, while the core training group participated in a six-week core training program in addition to the baseball-specific practice. Throwing velocity and ball-exit velocity were assessed before and after the six-week intervention period using a radar gun. The results showed that neither group experienced an increase in throwing velocity, but the core training group did experience a significant increase in ball-exit velocity. The study concluded that a six-week core training program led to increased ball-exit velocity among high school baseball players.

Summary:

This paper investigates the effects of core training on high school baseball performance. The study aimed to explore the effectiveness of a resistance training program targeting the muscles of the core in order to increase force production in torsional movements such as throwing and hitting in baseball. The study involved 24 male high school baseball players who were randomly assigned to either a control group or a core training group. The control group attended baseball-specific workouts twice a week for six weeks, while the core training group participated in a six-week core training program in addition to the baseball-specific practice. Throwing velocity and ball-exit velocity were assessed before and after the six-week intervention period using a radar gun. The results showed that neither group experienced an increase in throwing velocity, but the core training group did experience a significant increase in ball-exit velocity. The study concluded that a six-week core training program led to increased ball-exit velocity among high school baseball players.

Link to article

Felion, C. W., & DeBeliso, M. (2020). The effects of core training on high school baseball performance. Athens J. Sports, 7, 173-188.

Grunt = Velo - Grunting added 2.7 mph velocity for college pitchers

Grunting added 2.7 mph compared to non-grunting for D3 college pitchers!

There’s also some research on grunting for improving tennis serve speed.

If it works for throwing and serving, why not hitting?? 

Summary:

The document is a research article titled "The effect of grunting on overhead throwing velocity in collegiate baseball pitchers" published in the International Journal of Sports Science & Coaching. The purpose of the study was to determine the effect of grunting on overhead throwing velocity in collegiate baseball pitchers. Twenty-four division III collegiate baseball pitchers participated in the study and were asked to replicate the technique of grunting during their throws. Throwing velocities were measured with a radar gun. The results showed that throwing velocity was significantly higher during the grunting trials than the non-grunting trials. Age, height, weight, and handedness had no impact on the effect of grunting on throwing velocity. The authors suggest that grunting offers a simple and immediate means of enhancing throwing velocity in collegiate baseball pitchers, and more research is needed to determine the effects in populations of different skill levels.

Link to article

Tammany, J. E., O’Connell, D. G., Latham, S. E., Rogers, J. A., & Sugar, T. S. (2021). The effect of grunting on overhead throwing velocity in collegiate baseball pitchers. International Journal of Sports Science & Coaching, 16(5), 1111-1116.

Youth baseball swing mechanics compared to College-Pro

Differences between swings of youth (n=12, avg age = 14) and adult (n=12, (6 college, 6 pro), avg age = 22) baseball players against a pitching machine:

1.) Youth players start later, adult start earlier. 

This seems to be a common theme in research comparing more expert players to younger or less experienced players.

The college/pro started their swings 0.11 seconds earlier (time from front foot off ground to initial stride foot contact), which was statistically significant

2.) Adult/pro had more lead knee flexion on when the hands start to move forward

Interesting because the lead knee angle is similar at toe touch and ball contact.  Implies the adult/pro can flex into/onto front leg more and extend front leg faster to generate force (see yesterday’s post on vertical force relationship to youth swing)

3.) Youth players showed more range of motion

The youth players were more closed with the hips and torso to start and then more open at contact.  Including more hip-shoulder separation when the hands started moving forward.  But the angular velocity was lower the the pro/adult 

Summary:

This paper discusses a study that compared the hitting mechanics of youth and adult baseball players. The researchers found several differences in kinematic and temporal parameters between the two groups. Adult hitters had greater lead knee flexion, extended the lead knee and maintained a more open pelvis and upper torso position. They also had greater peak upper torso angular velocity, peak left elbow extension angular velocity, peak left knee extension angular velocity, and bat linear velocity at bat-ball contact. The study suggests that learning proper hitting mechanics at a young age may help reinforce these mechanics as players progress to higher levels of baseball.

Link to article

Escamilla, R. F., Fleisig, G. S., DeRenne, C., Taylor, M. K., Moorman, C. T., Imamura, R., ... & Andrews, J. R. (2009). A comparison of age level on baseball hitting kinematics. Journal of applied biomechanics, 25(3), 210-218.

Power characteristics in youth golf - Isometric Mid-Thigh Pull and swing performance

Really good paper here with loads of great info…

Start with this one:

Performance is MULTI-FACETED - in other words, training just for speed/power, approach or mechanics in isolation likely won’t cut it.  A well-rounded program is multi-disciplinary and multi-faceted.  Work on all of it!

Second:

There was a NEAR PERFECT correlation (r=.91) between peak force on the isometric mid-thigh high pull test and carry with the 6-iron and driver.  Pretty incredible strength of relationship

Third:

This study contributes to a growing body of evidence between physical power characteristics and swing performance.

Lastly:

Both movement competency and power are related to swing performance 

Summary:

The document discusses a study that aimed to determine the relationship between isometric mid-thigh pull (IMTP) force-time characteristics and swing performance in high-level youth golfers. Thirteen high-level youth golfers performed IMTP and swing testing, and the results revealed significant correlations between IMTP peak force and measures of swing performance such as club head speed (CHS) and carry distance. The study suggests that maximal lower body force production is important for swing performance in youth golfers and supports the use of IMTP as a testing tool in this population.

Link to article

Coughlan, Daniel; Taylor, Matthew J.D.; Jackson, Joanna; Ward, Nicholas; Beardsley, Chris. Physical Characteristics of Youth Elite Golfers and Their Relationship With Driver Clubhead Speed. Journal of Strength and Conditioning Research 34(1):p 212-217, January 2020. | DOI: 10.1519/JSC.0000000000002300

Isometric Mid-thigh high pull demo:

 

Head movement and eye tracking in elite cricket batters

How do elite cricket batters track the ball compared to less skilled batters?

The title of this article is also the summary: the head tracks and gaze predicts

2 main differences were found:

1) Elite batters tracked the ball with the head, not just the eyes, to maintain the ball closer to central gaze

2) Elite batters stayed “ahead” of ball flight with predictive saccades (eye moments) in anticipation of where the ball was going 

Summary:

This study discusses the eye and head movements of elite cricket batters and how they use predictive eye movement strategies to track the ball and hit it accurately. Previous studies claimed that batters cannot track the ball because it moves too quickly, but this study found that elite batters are able to track the ball by coupling the rotation of their head with the movement of the ball. They also use distinctive eye movement strategies to anticipate the location of the ball bounce and the location of bat-ball contact. These head and eye movement strategies contribute to their interceptive expertise in hitting the ball.

Link to article

Mann, D. L., Spratford, W., & Abernethy, B. (2013). The head tracks and gaze predicts: how the world’s best batters hit a ball. PloS one, 8(3), e58289.

When and how does bat speed happen?

This study measured the kinetics of bat speed in 99 amateur players with an average age of 19 years old. 

Bat angular velocity and bat head speed increase simultaneously around the half-way point of the swing (this looks like the time of when stride foot or heel lands, but is not specified in the study other than the image below) and they increase together until around the 80% mark.

The angular velocity is then converted to translational bat head speed into contact.

An interesting finding was that torque created in the X-Y directions did NOT have a significant relationship to bat speed.  The authors cited that torque exerted by the wrists is small compared to the amount of bat speed that gets created. 

Summary:

The document is a scientific study that aims to identify mechanisms to increase bat head speed in baseball batting. The study recorded the batting motion of ninety-nine amateur baseball players and analyzed the kinematics and kinetics of the bat. The results showed that the bat's rotational power increased with the torque exerted on the bat's grip, but declined just prior to impact. On the other hand, the bat's translational power increased just prior to impact. The study concluded that the bat's energy, by the application of rotational and translational power at different times, contributes to an increase in bat head speed in baseball batting. The study highlights the importance of increasing bat head speed in improving the performance of baseball batters.

Link to article 

Horiuchi, G., & Sakurai, S. (2016). Kinetic analyses on increase of bat head speed in baseball batting. International Journal of Sport and Health Science, 14, 94-101.

Swing changes in different strike zone locations for Division 1 college players

This research studied the changes to swings of Division 1 college baseball players while hitting off a tee in 9 different strike zone locations.  Changes to bat speed and bat angle were compared.  Bat speed and angle was higher on the inside pitch locations and there was also more angle to the bat for pitches lower in the zone.

Article summary:

The article examines changes in bat swing kinematics in different areas of the strike zone in collegiate baseball players. The aim of the investigation was to analyze swing kinematics, specifically the resultant velocity at ball contact (RVBC) and the angle of the bat at ball contact (BABC), in various regions of the strike zone. The study utilized markers on the tee and bat to record swing kinematic variables. Participants completed a series of swing trials in nine regions of their strike zone. The results of the study indicated significant differences in RVBC and BABC across the different regions of the strike zone. The findings suggest that understanding these changes in swing kinematics can help athletes and coaches identify areas of weakness and improve hitting performance during a game.

Link to article

Williams, C. C., Donahue, P. T., Wilson, S. J., Mouser, J. G., Hill, C. M., Luginsland, L. A., ... & Garner, J. C. (2020). Examining changes in bat swing kinematics in different areas of the strike zone in collegiate baseball players. International Journal of Kinesiology and Sports Science, 8(2), 1-6.

What’s the point of using a longer bat?

This study looked at the changes in the swing when using different length and weighted bats compared to normal bat in college players.  4 different combinations of long and weighted bats were compared to normal bat while batting off a tee.  The authors stated they had difficulty in making conclusions on the weighted bats so I’ll stick to some thoughts on the long bats.

What does training with a long bat do to your swing?

There was more angular displacement between the trunk and the pelvis and also for upper trunk rotation.  In hitting coach terms, I take this to mean there was more “separation” between the hips and shoulders in addition to more rotation of the shoulders toward contact when using the long bats.  And the longer the bat, the more separation was observed.

The size of the normal bat was .84m/.9kg which equates to 33 inch and nearly 32 ounces.  The 2 lb long bat was 1.1m/.9kg (43 inch, 32 ounce) and this was the only long bat with significantly high peak bat head speed than the normal bat. 

Article summary:

The aim of this study was to investigate the characteristics of hitting motion when using training bats with altered length and mass. Four different long bats (LB) and four different weight bats (WB) that had the equal moment of inertia (MOI) were manufactured based on a normal bat (NB; 0.84 m, 0.90 kg). The hitting motion of eleven male collegiate baseball players was analyzed using a VICON system to collect nine reflective markers fixed on the body and bat. Results showed that the angular displacement of the trunk twist tended to be larger in LB with increasing MOI. Compared to WB, LB may contribute to a larger angular displacement of trunk twist, particularly in players with smaller angular displacement of trunk twist in NB.

Link to article

Takahashi, K., Yamada, K., Kariyama, Y., Hayashi, R., Yoshida, T., Zushi, A., & Zushi, K. (2015). The characteristics of hitting motion using bats having different length and mass but equal moment of inertia. In ISBS-Conference Proceedings Archive.

Medicine ball training, lifting and specificity improves power in high school baseball players

This study covers a 12-week stepwise, periodized weight training program for high school baseball athletes.  The players were relatively untrained with around 1 year average lifting experience.  The program (image of protocol below) included weight training and 100 dry swings 3 times per week over 12 weeks with testing every 4 weeks.

~27% improvement in back squat

~17% improvement in bench press

Both groups improved rotational strength/power

Additional benefit to the group that added med ball work to the strength and dry swing program

Summary:

This document is a research study published in the Journal of Strength and Conditioning Research in 2007. The study investigated the effects of 12 weeks of medicine ball training on high school baseball players. The participants were randomly assigned to two groups, with one group performing full-body resistance exercises and taking bat swings, and the other group also performing additional rotational and full-body medicine ball exercises. The participants were tested on their torso rotational strength and sequential hip-torso-arm rotational strength before and after the 12-week training period. Both groups showed significant improvements in these measures, but the group performing the medicine ball exercises showed greater improvements. The study suggests that incorporating medicine ball training into a stepwise periodized resistance training program can enhance torso rotational strength and power in high school baseball players.

Link to article

Szymanski, D. J., Szymanski, J. M., Bradford, T. J., Schade, R. L., & Pascoe, D. D. (2007). Effect of twelve weeks of medicine ball training on high school baseball players. Journal of strength and conditioning research, 21(3), 894–901. https://doi.org/10.1519/R-18415.1

Rotational medicine ball throw relationship to throwing velocity, bat speed and exit velocity

Rotational medicine ball (6#) throw showed a moderate, statistically significant relationship to throwing velocity, bat speed and exit velocity (off a tee) in college (division 3) baseball players. 

The average velocities were:

MB throw - 25.3 mph

Bat speed - 73.8 (measured with blast motion sensor)

Exit velocity - 83.6

Pitching velocity - 81.9

Article Summary:

The document is a research study titled "Rotational Medicine Ball Throw Velocity Relates to NCAA Division III College Baseball Player Bat Swing, Batted Baseball, and Pitching Velocity." The study aims to determine the relationship between rotational medicine ball throw velocity (RMBTV) and bat swing velocity, batted baseball velocity, and pitching velocity in collegiate baseball players.

The study involved 35 NCAA Division III players, including 15 pitchers and 23 hitters. The players participated in various whole-body power tests, including the two-legged standing broad jump for distance, lateral-to-medial jump for distance, and RMBTV. The researchers measured the correlational relationship strength between these tests and bat swing velocity, batted baseball velocity, and pitching velocity.

Results showed that moderate relationships were observed between bat swing velocity and RMBTV, pitching velocity and RMBTV, and batted baseball velocity and RMBTV. However, no significant relationships were found between the two-legged standing broad jump for distance or the lateral-to-medial jump for distance tests and bat swing velocity or pitching velocity.

Based on these findings, the researchers suggest that RMBTV may be a more reliable indicator of bat swing velocity, batted baseball velocity, and pitching velocity in collegiate baseball players. They also propose that further studies should explore whether coordination developed during RMBTV movements can help prevent shoulder and elbow injuries in baseball players.

Link to abstract

Taniyama, Daiki; Matsuno, Jun; Yoshida, Kei; Pyle, Brandon; Nyland, John. Rotational Medicine Ball Throw Velocity Relates to NCAA Division III College Baseball Player Bat Swing, Batted Baseball, and Pitching Velocity. Journal of Strength and Conditioning Research 35(12):p 3414-3419, December 2021. | DOI: 10.1519/JSC.0000000000004148

 

Difference between hitting tee and soft toss drill in college softball players

Capability to measure the differences between drills is great for coaching.  It makes it easier to select appropriate drills based on the individual player’s movement capabilities.  It’s also important to recognize that even a small change in drill/environment is likely to alter the player’s mechanics in some way.

Article summary:

The document is a research article titled "Kinematic differences between hitting off a tee versus front toss in collegiate softball players" published in the International Biomechanics journal. The study aims to compare the kinematics of two hitting conditions, hitting off a stationary tee and hitting from a front toss practice pitcher. The study includes 22 NCAA Division I Collegiate softball players and analyzes various kinematic variables such as lead knee flexion, trunk rotation, and pelvis rotation. The results indicate that there are significant differences in swing mechanics between the two conditions. The front toss condition showed greater lead knee flexion at foot contact and greater trunk rotation towards the back side at ball contact. On the other hand, the tee condition showed greater trunk lateral flexion and rotation towards the lead side at follow through. The study suggests that athletes should implement techniques most applicable to a competition setting, such as front toss. The article was published online in May 2018 and can be accessed through the journal's website.

Link to article

Washington, J., & Oliver, G. (2018). Kinematic differences between hitting off a tee versus front toss in collegiate softball players. International Biomechanics, 5(1), 30-35.