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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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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