Inter-pitcher and Intra-pitcher Comparisons on the Relationship between Trunk Kinematics and Ball Speed in Collegiate Baseball Pitchers

It is known that high elbow valgus torque in the pitching motion can contribute to the occurrence of elbow injury. Lately, studies have shown pitchers with UCL tears had significantly lower balance measures than healthy players when tested after injury occurred. There is a paucity of research on the effect of balance-specific training on the joint loading of the elbow and player performance in baseball pitching. PURPOSE: To investigate the effect of a balance training intervention on the biomechanical factors that can contribute to a pitcher’s increased risk of elbow injury. METHODS: Thirteen collegiate baseball pitchers were randomly assigned to a training group: control or intervention. The control group did only the team training and the intervention group did the team training and a specific balance training program. The intervention was performed 3 times a week for 6 weeks. Measurements of balance (Y-Balance), limits of stability (center of pressure excursion), ball speed, and joint kinematics and kinetics, specifically maximum elbow valgus torque (MEV), through motion capture were collected before and after the 6-week training program. RESULTS: None of the outcome measures showed a significant difference between training type (Y-Balance p=.405; COP excursion p=.537, ball speed p=.150; MEV p=.945). Three outcome measures, COP excursion (p=.007), ball speed (p=.003), and MEV (p<.001) showed significant decreases over time regardless of training type. A Pearson Correlation was run for the entire study population (n=13) between ball speed and MEV for initial (p=.409) and final (p=-.300) testing and showed no significant correlation between the variables. CONCLUSION: The balance training program had no observable effect on a pitchers’ pitching performance or elbow kinetics. There was no significant difference between groups in pre or post measures, therefore, any change in balance measures can be attributed to normal in-season training strength development.

The aims of this study were (i) to determine whether significant three-dimensional (3D) trunk kinematic differences existed between a driver and a five-iron during a golf swing; and (ii) to determine the anthropometric, physiological, and trunk kinematic variables associated with clubhead speed. Trunk range of motion and golf swing kinematic data were collected from 15 low-handicap male golfers (handicap = 2.5 ± 1.9). Data were collected using a 10-camera motion capture system operating at 250 Hz. Data on clubhead speed and ball velocity were collected using a real-time launch monitor. Paired t-tests revealed nine significant (p ≤ 0.0019) between-club differences for golf swing kinematics, namely trunk and lower trunk flexion/extension and lower trunk axial rotation. Multiple regression analyses explained 33.7–66.7% of the variance in clubhead speed for the driver and five-iron, respectively, with both trunk and lower trunk variables showing associations with clubhead speed. Future studies should consider the role of the upper limbs and modifiable features of the golf club in developing clubhead speed for the driver in particular.

In baseball pitching, pivot leg is known to play an important role in linear acceleration down the mound. However, its contribution to the rotational movements of the proximal segments such as pelvis and upper body remains unknown. This study aimed to investigate the association between the pivot leg rotation, pelvis rotation, and trunk separation during the stride phase of baseball pitching in relation to ball speed. Three-dimensional kinematic data from 18 collegiate baseball pitchers were obtained during the maximal-effort pitches. The rotational angles and angular velocities of the pivot leg, pelvis, and upper trunk in the stride phase of pitching delivery were calculated to investigate the association of pivot leg rotation with pelvis rotation, upper trunk rotation, and trunk separation. The results showed that the rotational angular displacement of the pivot leg was positively correlated with pelvis rotation and negatively correlated with trunk separation during the stride phase and at the instant of stride foot contact. The peak rotation angular velocity of the pivot leg was also negatively correlated with trunk separation angle at stride foot contact. The trunk separation angle at the stride foot contact was the only variable that was positively correlated with ball speed. These results indicated that the pivot leg and pelvis behave similarly in terms of rotational movement in the transverse plane. Achieving greater trunk separation at stride foot contact, mainly by increasing pelvis rotation in association with pivot leg rotation, might increase ball speed. These findings can be useful when the coaches give instructions to modify the rotational mechanics of their pitchers.

OBJECTIVES This study analyzed the effects of core-coiling training for 12 weeks on the pitch velocity and control, which are key factors in skill-related fitness and performance of college baseball pitchers.METHODS The study involved 29 college baseball pitchers from D University in B City, who were di-vided into Core-Coiling Training group (CCTG, n=15) and Resistance Weight Training group (RWTG, n=14). The CCTG underwent core-coiling training for 50 minutes, four times per week, over a period of 12 weeks, while the RWTG maintained regular team training. Baseball related physical fitness and pitching skills were measured before and after the intervention.RESULTS The Resistance weight training group (RWTG) showed significant improvements in func-tional fitness, specifically in Grip strength. The core-coiling training group (CCTG) showed significant improvements in functional fitness, specifically in explosive power and agility. Furthermore, the CCTG demonstrated significant increases in both maximum ball speed and average ball speed post-intervention. In terms of intergroup comparison, the CCTG showed significantly greater gains in agility, maximum ball speed, and average ball speed compared to the resistance weight training group.CONCLUSIONS Based on these results, core-coiling training was found to be an effective intervention that positively impacts the functional fitness and pitching skills of college baseball pitchers. This suggests that Core-Coiling training can be proposed as a new, evidence-based train-ing methodology.

Relationships between ball velocity and throwing mechanics in collegiate baseball pitchers

Background: A baseball pitcher’s ability to maximize ball speed while avoiding shoulder and elbow injuries is an important determinant of a successful career. Pitching injuries are attributed to microtrauma brought about by the repetitive stress of high-magnitude shoulder and elbow kinetics. Hypothesis: Over a number of pitches, variations in timing peak angular velocities of trunk segment rotations will be significantly associated with ball speed and upper extremity kinetic parameters. Study Design: Descriptive laboratory study. Methods: Kinematic and kinetic data were derived from 9 to 15 fastball pitches performed by 16 active, healthy collegiate (n = 8) and professional (n = 8) pitchers via 3-dimensional motion capture (240 Hz). Each pitch was decomposed into 4 phases corresponding to the time between peak angular velocities of sequential body segment rotations. Four mixed models were used to evaluate which phases varied significantly in relation to ball speed, peak shoulder proximal force, peak shoulder internal rotation torque, and peak elbow varus torque. Mixed-model parameter coefficient estimates were used to quantify the influence of these variations in timing on ball speed and upper extremity kinetics. Results: All 4 mixed models were significant (P < .05). The time from stride-foot contact to peak pelvis angular velocity varied significantly in relation to all upper extremity kinetic parameters and ball speed. Increased time in this phase correlated with decreases in all parameters. Decreased ball speed also correlated with increased time between peak upper torso and elbow extension angular velocities. Decreased shoulder proximal force also correlated with increased time between peak pelvis and upper torso angular velocities. Conclusion: There are specific phases that vary in relation to ball speed and upper extremity kinetic parameters, reinforcing the importance of effectively and consistently timing segmental interactions. For the specific interactions that varied significantly, increased phase times were associated with decreased kinetics and ball speed. Clinical Relevance: Although increased time within specific phases correlates with decreases in the magnitude of upper extremity kinetics linked to overuse injuries, it also correlates with decreased ball speed. Based on these findings, it may appear that minimizing the risk of injury (ie, decreased kinetics) and maximizing performance quality (ie, increased ball speed) are incompatible with one another. However, there may be an optimal balance in timing that is effective for satisfying both outcomes.

The purpose of this study was to investigate the immediate effects of assisted and resisted training using different weight balls on ball speed and accuracy in baseball pitching. Eight male university baseball players were assigned as subjects. The experiment used a standard 145-gram baseball and two heavier or lighter balls with weights increased or decreased by 10% respectively. The subjects were required to pitch these balls and/or standard ball either six or eighteen times under different training trial conditions: 1) pitching the weighted ball only, 2) pitching the lightened ball only, 3) pitching the standard ball only, and 4) pitching three kinds of balls in order of the weighted, standard and lightened balls. Immediately after each training trial, the standard ball was pitched five times respectively (test trial). The ball speed of each trial was measured with a speed gun, and the distance from the center of target to the position of the ball pitched on the target was calculated using a video digitizing system. The results are summarized as follows: 1) In the training trials, the ball speed increased as the ball weight was decreased. 2) In the test trials, immediately after pitching the lightened ball both six (6Atest) and eighteen times (18Atest), and the three different kinds of balls eighteen times (18Ctest), the ball speeds were seen to be significantly higher than that of other test trials (p<0.01). 3) Although there were no significant differences in the ball speed in the above three test trials, a relatively higher ball speed was observed in 18Atest. 4) As for the distance from the center of target to the position of the ball pitched on the target, there were no significant differences among any trials.

Context: The lumbopelvic-hip musculature plays a critical role in controlling trunk movement during pitching. Training interventions targeting these muscles have been shown to enhance muscle function and increase ball speed. However, evidence linking improvements in lumbopelvic-hip strength and power to changes in trunk kinematics and joint moments during pitching is lacking. Objective: To investigate the effects of an 8-week strength training intervention targeting the lumbopelvic-hip muscles on muscle function and pitching biomechanics in adolescent pitchers. Design: Controlled Laboratory Study. Setting: Research laboratory / Training facility Patients or Other Participants: Fifty-four high school pitchers enrolled into either an intervention or a control group. Intervention: Eight-week training targeting lumbopelvic-hip muscles. Main Outcome Measures: Changes in lumbopelvic-hip muscle function, trunk kinematics during pitching, joint loading, and ball velocity. Results: The intervention resulted in greater improvements in trunk rotation strength and power (p = 0.002 -0.017) and increases in elbow varus moment (p = 0.046) and ball speed (p = 0.014). Although no significant between-groups differences were observed in pitching kinematic correlated with a smaller pelvis rotation (a more “closed” pelvis) at lead foot contact, smaller trunk separation angle at lead foot contact, and later timing of peak upper torso rotation velocity (|r| = 0.436 - 0.566). Conclusion: The intervention effectively improved trunk rotational strength and power and ball speed, but also increased elbow stress. This finding underscores the importance of reducing pitch counts or extending rest periods as ball speed increases. The intervention produced only limited changes in pitching kinematics. Enhanced trunk rotational strength and power in the intervention group were associated with positive changes in trunk kinematics, but no other kinematic adjustments. Combining strength training with technical feedback and extending the intervention duration may lead to greater biomechanical adaptations.

A gait analysis of simulated knee flexion contracture to elucidate knee-spine syndrome

This study investigated age-related differences in trunk kinematics during walking in healthy men. Secondary aims were to investigate the covarying effects of physical activity (PA) and lumbar paravertebral muscle (LPM) morphology on trunk kinematics, and the effect of age on interplanar coupling between the trunk and pelvis. Three-dimensional (3D) trunk and pelvis motion data were obtained for 12 older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) healthy men during walking at a self-selected speed along a 10 m walkway. Phase-specific differences were observed in the coronal and transverse planes, with midstance and swing phases highlighted as instances when trunk and pelvic kinematics differed significantly (p < 0.05) between the younger group and older group. Controlling for age, fewer significant positive correlations were revealed between trunk and pelvic ranges and planes of motion. LPM morphology and PA were not significant covariates of age-related differences in trunk kinematics. Age-related differences in trunk kinematics were most apparent in the coronal and transverse planes. The results further indicate ageing causes an uncoupling of interplanar upper body movements during gait. These findings provide important information for rehabilitation programmes in older adults designed to improve trunk motion, as well as enable identification of higher-risk movement patterns related to falling.

Background:Pitching-related elbow injuries remain prevalent across all levels ofbaseball. Elbow valgus torque has been identified as a modifiable riskfactor of injuries to the ulnar collateral ligament in skeletally maturepitchers.Purpose:To examine how segmental energy flow (power) influences elbow valgus torqueand ball speed in professional versus high school baseball pitchers.Study Design:Descriptive laboratory study.Methods:A total of 16 professional pitchers (mean age, 21.9 ± 3.6 years) and 15 highschool pitchers (mean age, 15.5 ± 1.1 years) participated in marker-basedmotion analysis of baseball pitching. Ball speed, maximum elbow valgustorque (MEV), temporal parameters, and mechanical power of the trunk, upperarm, and forearm were collected and compared using parametric statisticalmethods.Results:Professional pitchers threw with a higher ball speed (36.3 ± 2.9 m/s)compared with high school pitchers (30.4 ± 3.5 m/s) (P =.001), and MEV was greater in professional pitchers (71.3 ± 20.0 N·m) thanin high school pitchers (50.7 ± 14.6 N·m) (P = .003). Nosignificant difference in normalized MEV was found between groups(P = .497). Trunk rotation time, trunk power, and upperarm power combined to predict MEV (r = 0.823,P < .001), while trunk rotation time and trunk powerwere the only predictors of ball speed (r = 0.731,P < .001). There were significant differencesbetween the professional and high school groups in the timing of maximumpelvis rotation velocity (42.9 ± 9.7% of the pitching cycle [%PC] vs 27.9 ±23.4 %PC, respectively; P < .025), maximum trunkrotation (33 ± 16 %PC vs 2 ± 23 %PC, respectively; P =.001), and maximum shoulder internal rotation velocity (102.4 ± 8.9 %PC vs93.0 ± 11.7 %PC, respectively; P = .017).Conclusion:The power of trunk motion plays a critical role in the development of elbowvalgus torque and ball speed. Professional and high school pitchers do notdiffer in elbow torque relative to their respective size but appear to adoptdifferent patterns of segmental motion.Clinical Relevance:Because trunk rotation supplies the power associated with MEV and ball speed,training methods aimed at core stabilization and flexibility may benefitprofessional and high school pitchers in reducing the injury risk andimproving pitching performance.

How maximal whole-body and segmental angular momenta relate to fastball speeds in high school baseball pitchers.

In baseball pitching, suppressing trunk rotation while rotating the pelvis in the early phase of arm cocking is important for throwing a fast ball. However, quantitative evaluation of trunk rotation during pitching has not been established, and its associations with elbow and shoulder torques are unclear. The purpose of this study was to examine the correlation of a new measure of trunk rotation suppression with ball speed and elbow and shoulder torques during pitching. Eighteen adult male baseball pitchers (21.7 ± 1.2 years old) participated. Three qualified pitches were analysed using a three-dimensional motion capture system. Trunk rotation velocity, normalised to the peak velocity, was derived at the time of peak pelvic velocity. Pearson’s correlation coefficient was used to determine correlations. The normalised trunk rotation velocity at the peak pelvic velocity was significantly correlated with elbow valgus torque (R = −0.508, P = 0.032), shoulder external rotation torque (R = −0.507, P = 0.032) and ball speed (R = −0.504, P = 0.033). A smaller normalised trunk rotation angular velocity at the time of peak pelvic rotation velocity could increase ball speed but may also increase elbow and shoulder torques among pitchers who demonstrate trunk rotation after foot contact.

The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation) 1.7 years) pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph) with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.

&lt;p&gt;目的：本研究欲探討成棒選手肩髖的旋轉及肩髖分離程度與球速間的相關性，用以尋找提升球速的方法。方法：以 18 位大專公開一級棒球投手作為研究參與者，同時利用慣性感測 (IMU)、二維影像分析系統及測速槍測量研究參與者之投球運動學參數，包括肩與骨盆在各時間點的旋轉角度、肩髖分離的角度、旋轉峰值時機及球速等。以皮爾森積差相關係數分析肩與骨盆的旋轉情況及肩髖分離程度與球速之間是否具有相關性。結果：本研究顯示除了上軀幹在膝蓋最高點 (r =-.295, p =.441)外，其餘分別為上軀幹在前導腳落地時 (r = -.821, p &lt; .001)、上軀幹在球離手時 (r = .765, p = .016)、骨盆在膝蓋最高點時 (r = -.791, p = .011)、骨盆在前導腳落地時 (r = .906, p= .001)、骨盆在球離手時 (r = .951, p &lt; .001)，都與球速呈顯著相關；上軀幹與骨盆的旋轉速度峰值、時機與球速呈顯著相關 (r = .934, p &lt; .001)、(r = .969, p &lt; .001)、(r = .881, p = .002)、(r = -.749, p = .02)；肩髖分離程度與上軀幹和骨盆的旋轉及球速皆呈顯著相關。結論：本研究顯示不僅是上軀幹，骨盆的旋轉與球速也息息相關，因此在投球動作上應注重投球動作的整體性，而非強調單一肢段的發力，且若能同時妥善運用肩髖分離，則能提升運動表現。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Purpose: This study aims to investigate the correlation between hip-shoulder and separation degree with ball speed in skilled baseball pitchers to identify methods for enhancing pitching velocity. Methods: Eighteen collegiate level-Ⅰbaseball pitchers participated as research subjects. An inertial measurement unit (IMU), a two-dimensional motion analysis system, and a radar gun were employed to measure the kinematic parameters of the pitching motion. These parameters included rotational angles of the shoulder and pelvic at various time points, the degree of hip-shoulder separation, peak rotation timing, and ball velocity. Pearson correlation coefficients between ball velocity, hip shoulder separation, and all trunk and pelvic kinematic variables were computed, and the level of significance was set at &amp;alpha; = .05. Results: The results indicate that, except for the upper trunk at the maximum knee height(r = -.295, p = .441), the rest were significantly related with ball velocity: the upper trunk at the landing of the leading foot (r = -.821, p&lt; .001), the upper trunk at the ball off hand (r = .765, p = .016), the pelvic at the maximum knee height (r = -.791, p = .011), the pelvic at the landing of the leading foot (r = .906, p = .001), and the pelvic at the ball off hand (r = .951, p &lt; .001). The peak rotation velocity and the timing of the peak rotation velocity of the upper trunk and pelvic is also significantly related to ball velocity(r = .934, p &lt; .001)、(r = .969, p &lt; .001)、(r = .881, p = .002)、(r = -.749, p = .02). The degree of shoulder-hip separation is significantly correlated with the rotation of the upper trunk and pelvic and ball velocity. Conclusion: Based on the findings of this study, we know the significance of not only the upper trunk but also pelvic rotation with ball velocity. Therefore, a holistic approach to pitching mechanics, emphasizing overall motion rather than isolating individual segments, is crucial. Additionally, effectively utilizing hip-shoulder separation can enhance overall athletic performance in baseball pitching.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;