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.

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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.

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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.

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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.

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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.