Increased Shoulder Distraction Force and Shoulder Horizontal Abduction in Professional Baseball Pitchers With Discordant Torso Rotation Order

2021 ◽  
pp. 036354652110413
Author(s):  
Joseph E. Manzi ◽  
Brittany Dowling ◽  
Joshua S. Dines ◽  
Alexander Richardson ◽  
Kathryn L. McElheny ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Internal Rotation ◽  
External Rotation ◽  
Rotation Velocity ◽  
Mean Difference ◽  
Professional Baseball ◽  
Pelvic Rotation ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Distraction Force

Background: Inefficient energy transfer from the pelvis and trunk has been shown to increase compensation at the level of the shoulder. Kinetic chain sequencing of the core segments is underexamined in professional baseball pitchers, especially as it relates to changes in upper extremity kinetics. Purpose: To evaluate elbow and shoulder kinetics in a cohort of professional pitchers differentiated by instances of discordant pelvic to upper torso sequencing during the pitch. Study Design: Descriptive laboratory study. Methods: 285 professional baseball pitchers were evaluated using 3D motion capture (480 Hz). Pitchers were divided into “chronological” and “discordant” groups based on whether maximum pelvic rotation velocity occurred before (chronological) or after (discordant) maximum upper torso rotation velocity during the pitch motion. Pelvic, upper torso, and shoulder kinematic parameters, shoulder distraction force, shoulder internal rotation torque, and pitch efficiency (PE) were compared between groups. Results: Pitchers with discordant torso sequencing (n = 30; 110 pitches) had greater shoulder horizontal adduction at maximum external rotation (mean difference, 3.6°; 95% CI, −5.2° to −2.0°; t = −4.5; P < .001) and greater maximum shoulder external rotation (mean difference, 3.7°; 95% CI, 5.7° to 1.5°; t = −3.5; P < .001) than chronological pitchers (n = 255; 2974 pitches). PE did not differ between groups ( P = .856), whereas ball velocity was significantly faster in the discordant group (mean difference, 0.6 m/s; 95% CI, −1.1 to −0.3 m/s; t = −3.3; P = .0012). Chronological pitchers had significantly reduced shoulder distraction force (mean difference, −4.7% body weight (BW); 95% CI, −7.9% to −1.5% BW; t = −2.9; P = .004) with no difference in shoulder internal rotation torque ( P = .160). These kinematic and kinetic differences were not observed when accounting for interpitcher variability. Conclusion: Between pitchers, those who had a discordant pelvic to upper torso sequence experienced significantly greater shoulder distraction forces, potentially compensating by increasing maximum shoulder external rotation and horizontal abduction. Achieving maximal pelvic rotation velocity before maximal rotation velocity may be advantageous in preventing compensation at the upper extremity and excessive throwing arm loading. Clinical Relevance: Identifying risk factors for increased upper extremity forces has potential implications in injury prevention. Specifically, mitigating shoulder distraction forces may be beneficial in reducing risk of injury.

The influence of shoulder abduction and external rotation on throwing arm kinetics in professional baseball pitchers

2021 ◽  
pp. 175857322110103
Author(s):  
Joseph E Manzi ◽  
Brittany Dowling ◽  
Nicolas Trauger ◽  
Michael C Fu ◽  
Benjamin R Hansen ◽  
...  
Keyword(s):  
Body Weight ◽  
External Rotation ◽  
Professional Baseball ◽  
Shoulder Abduction ◽  
3D Motion Analysis ◽  
Ball Release ◽  
Ball Velocity ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Distraction Force

Background The relationships between shoulder abduction and external rotation with peak kinetic values at the shoulder and elbow in professional baseball pitchers are not well established. Methods Professional pitchers ( n = 322) threw 8–12 fastballs under 3D motion analysis (480 Hz). Pitchers were stratified into quartiles by shoulder abduction and external rotation at distinct timepoints. Regression analyses were performed to quantify associations between shoulder position and kinetics. Results Shoulder abduction remained relatively consistent throughout the pitch (foot contact–ball release: 85.5 ± 11.1–90.7 ± 8.4°); shoulder external rotation increased dramatically (foot contact–ball release: 30.8 ± 24.6–165.2 ± 9.7°). For every 10° increase in maximum shoulder rotation, shoulder superior force increased by 2.3% body weight ( p < 0.01), shoulder distraction force increased by 5.9% body weight ( p < 0.01), and ball velocity increased by 0.60 m/s ( p < 0.01). Shoulder abduction was significantly associated with shoulder superior force at all timepoints but not with ball velocity ( p > 0.05). For every 10° increase in shoulder abduction at ball release, shoulder superior force increased by 3.7% body weight ( p < 0.01) and shoulder distraction force increased by 11.7% body weight ( p < 0.01). Conclusion Increased shoulder abduction at ball release and increased maximum shoulder external rotation were associated with greater superior and distraction forces in the shoulder. Pitchers can consider decreasing shoulder abduction at later stages of the pitch to around 80° in order to minimize shoulder superior force, with no impact on ball velocity.

scholarly journals Baseball Pitchers’ Kinematic Sequences and Their Relationship to Elbow and Shoulder Torque Production

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0042
Author(s):  
Donna Moxley Scarborough ◽  
Shannon E. Linderman ◽  
Javier E. Sanchez ◽  
Eric M. Berkson
Keyword(s):  
Upper Extremity ◽  
External Rotation ◽  
Kinetic Chain ◽  
Joint Torques ◽  
Ball Velocity ◽  
Collegiate Baseball ◽  
Angular Velocities ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
The Ideal

Objectives: Ball velocity is generated during the overhead baseball pitch via efficient force transmission up the kinetic chain, from the lower body up and outward to the throwing hand. The kinematic sequence, or the sequential timing pattern of peak angular velocities of body segments during a pitch, provides insight to segment position and motion control that drives the kinetic chain (Putnam CA, 1993). Previous publications report an ideal kinematic sequence (KS) where the timing of each body segment’s peak angular velocity occurs in a proximal-to-distal (PDS) pattern resulting in greater ball velocity and reduction in throwing arm injury risk (Fortenbaugh D, et.al, 2009). A recent study revealed that baseball pitchers perform a variety of KSs (Scarborough DM et.al, 2018). There is no known investigation of the relationship of kinematic sequences and throwing arm joint torques. The purpose of this study was to 1) identify the number of different KSs performed by each pitcher and 2) compare elbow valgus and shoulder external rotation (ER) and extension (Ext) torques between the 3 primary KSs performed during the fastball pitch. Methods: Fourteen collegiate baseball pitchers (20.57 ± 1.91 yr) underwent 3D biomechanical pitch analysis using 20 motion-capture Vicon MX™ cameras (360 Hz). A total of 119 fastball pitches with an average of 8.5 ± 2.71 pitches per player were analyzed. Elbow valgus and shoulder external rotation and extension torques were calculated. The timing of peak angular velocities for the pelvis, trunk, arm, forearm and hand body segments were recorded to generate each pitch’s KS. KSs were then divided into groups based on similarities to the ideal PDS pattern. ANCOVA statistical analyses were performed to compare joint torques across these KS groups with ball velocity as a covariate. Results: A total of 13 different KSs were observed across the 14 pitchers resulting in an average of 3 ± 1.41 different KSs per pitcher. Three different primary KS groups were identified: (1) PDS group: with a KS closest to the ideal PDS pattern (2) the Altered Distal Upper Extremity segment: with the forearm peaking after the hand (the most common group) and (3) Altered Proximal Upper Extremity segment order with the arm segment peaking after the hand (2nd most common). Across these three primary KS patterns, statistically significant differences were noted for elbow valgus torque [F(62,2) = 8.785, ɳ2 = .221, p < 0.00], shoulder external rotation (ER) torque [F(62,2) = 14.127, ɳ2 = .313, p < 0.00] and shoulder extension (Ext) torque [F(62,2) = 13.237, ɳ2 = .299, p < 0.00] (Figure 1). Conclusion: Our findings demonstrate that collegiate baseball pitchers performed an average of 3 different kinematic sequence patterns during fastball pitching. This is the first study to demonstrate a relationship between KSs and elbow and shoulder torque production. As anticipated, the PDS KSs produced the least torque across the elbow and shoulder joints. Alterations in Distal Upper Extremity KS was most common and generated the greatest shoulder Ext torques. Alterations in the Proximal Upper Extremity KS demonstrated the greatest elbow valgus and shoulder ER. Further study of the influence of kinematic sequence on joint torques in the baseball pitch may provide insight into pitching injuries and injury avoidance programs.

scholarly journals Correlation of Shoulder and Elbow Kinetics With Ball Velocity in Collegiate Baseball Pitchers

2015 ◽  
Vol 50 (6) ◽  
pp. 629-633 ◽  
Author(s):  
Eric G. Post ◽  
Kevin G. Laudner ◽  
Todd A. McLoda ◽  
Regan Wong ◽  
Keith Meister
Keyword(s):  
External Rotation ◽  
Pearson Correlation ◽  
Anatomical Landmarks ◽  
Positive Correlation ◽  
Weak Positive Correlation ◽  
Ball Velocity ◽  
Collegiate Baseball ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Distraction Force

Context Throwing a baseball is a dynamic and violent act that places large magnitudes of stress on the shoulder and elbow. Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables throughout the throwing motion. However, very little research has directly examined the relationship between these kinetic variables and ball velocity. Objective To examine the correlation of peak ball velocity with elbow-valgus torque, shoulder external-rotation torque, and shoulder-distraction force in a group of collegiate baseball pitchers. Design Cross-sectional study. Setting Motion-analysis laboratory. Patients or Other Participants Sixty-seven asymptomatic National Collegiate Athletic Association Division I baseball pitchers (age = 19.5 ± 1.2 years, height = 186.2 ± 5.7 cm, mass = 86.7 ± 7.0 kg; 48 right handed, 19 left handed). Main Outcome Measure(s) We measured peak ball velocity using a radar gun and shoulder and elbow kinetics of the throwing arm using 8 electronically synchronized, high-speed digital cameras. We placed 26 reflective markers on anatomical landmarks of each participant to track 3-dimensional coordinate data. The average data from the 3 highest-velocity fastballs thrown for strikes were used for data analysis. We calculated a Pearson correlation coefficient to determine the associations between ball velocity and peak elbow-valgus torque, shoulder-distraction force, and shoulder external-rotation torque (P &lt; .05). Results A weak positive correlation was found between ball velocity and shoulder-distraction force (r = 0.257; 95% confidence interval [CI] = 0.02, 0.47; r2 = 0.066; P = .018). However, no significant correlations were noted between ball velocity and elbow-valgus torque (r = 0.199; 95% CI = −0.043, 0.419; r2 = 0.040; P = .053) or shoulder external-rotation torque (r = 0.097; 95% CI = −0.147, 0.329; r2 = 0.009; P = .217). Conclusions Although a weak positive correlation was present between ball velocity and shoulder-distraction force, no significant association was seen between ball velocity and elbow-valgus torque or shoulder external-rotation torque. Therefore, other factors, such as improper pitching mechanics, may contribute more to increases in joint kinetics than peak ball velocity.

Descriptive Profile of Hip Rotation Range of Motion in Elite Tennis Players and Professional Baseball Pitchers

2007 ◽  
Vol 35 (8) ◽  
pp. 1371-1376 ◽  
Author(s):  
Todd S. Ellenbecker ◽  
Gail A. Ellenbecker ◽  
E. Paul Roetert ◽  
Rogerio Teixeira Silva ◽  
Greg Keuter ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Internal Rotation ◽  
Hip Joint ◽  
External Rotation ◽  
Professional Baseball ◽  
Tennis Players ◽  
Active Range Of Motion ◽  
Baseball Pitchers ◽  
Hip Rotation ◽  
Bilateral Difference

Background Repetitive loading to the hip joint in athletes has been reported as a factor in the development of degenerative joint disease and intra-articular injury. Little information is available on the bilateral symmetry of hip rotational measures in unilaterally dominant upper extremity athletes. Hypothesis Side-to-side differences in hip joint range of motion may be present because of asymmetrical loading in the lower extremities of elite tennis players and professional baseball pitchers. Study Design Cohort (cross-sectional) study (prevalence); Level of evidence, 1. Methods Descriptive measures of hip internal and external rotation active range of motion were taken in the prone position of 64 male and 83 female elite tennis players and 101 male professional baseball pitchers using digital photos and computerized angle calculation software. Bilateral differences in active range of motion between the dominant and nondominant hip were compared using paired t tests and Bonferroni correction for hip internal, external, and total rotation range of motion. A Pearson correlation test was used to test the relationship between years of competition and hip rotation active range of motion. Results No significant bilateral difference (P > .005) was measured for mean hip internal or external rotation for the elite tennis players or the professional baseball pitchers. An analysis of the number of subjects in each group with a bilateral difference in hip rotation greater than 10° identified 17% of the professional baseball pitchers with internal rotation differences and 42% with external rotation differences. Differences in the elite male tennis players occurred in only 15% of the players for internal rotation and 9% in external rotation. Female subjects had differences in 8% and 12% of the players for internal and external rotation, respectively. Statistical differences were found between the mean total arc of hip range of internal and external rotation in the elite tennis players with the dominant side being greater by a clinically insignificant mean value of 2.5°. Significantly less (P < .005) dominant hip internal rotation and less dominant and nondominant hip total rotation range of motion were found in the professional baseball pitchers compared with the elite male tennis players. Conclusion This study established typical range of motion patterns and identified bilaterally symmetric hip active range of motion rotation values in elite tennis players and professional baseball pitchers. Asymmetric hip joint rotational active range of motion encountered during clinical examination and screening may indicate abnormalities and would indicate the application of flexibility training, rehabilitation, and further evaluation.

Biomechanics of the Shoulder in Youth Baseball Pitchers

2005 ◽  
Vol 33 (11) ◽  
pp. 1716-1722 ◽  
Author(s):  
Michelle B. Sabick ◽  
Young-Kyu Kim ◽  
Michael R. Torry ◽  
Michael A. Keirns ◽  
Richard J. Hawkins
Keyword(s):  
Body Weight ◽  
External Rotation ◽  
Pitching Motion ◽  
Little League ◽  
Youth Baseball ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Force Components ◽  
Simulated Game ◽  
Distraction Force

Background The effects of repetitive throwing on the shoulders of developing athletes are not well understood because of the paucity of data describing the biomechanics of youth pitchers and the plasticity of the developing skeleton. Hypothesis The direction and magnitude of the stresses that exist at the proximal humeral physis during the fastball pitching motion are consistent with the development of proximal humeral epiphysiolysis (Little League shoulder) and/or humeral retrotorsion. Study Design Descriptive laboratory study. Methods A total of 14 elite youth baseball pitchers (mean age, 12.1 ± 0.4 years) were filmed from the front and dominant side while throwing fastballs in a simulated game. The net force and torque acting on the humerus throughout the throwing motion were calculated using standard biomechanical techniques. Results The external rotation torque about the long axis of the humerus reached a peak value of 17.7 ± 3.5 N.m (2.7% ± 0.3% body weight × height) just before maximum shoulder external rotation. A shoulder distraction force of 214.7 ± 47.2 N (49.8% ± 8.3% body weight) occurred at, or just after, ball release. Conclusion Shear stress arising from the high torque late in the arm-cocking phase is large enough to lead to deformation of the weak proximal humeral epiphyseal cartilage, causing either humeral retrotorsion or proximal humeral epiphysiolysis over time. The stresses generated by the external rotation torque are much greater than those caused by distraction forces generated during the pitching motion of youth baseball pitchers. Clinical Relevance The motion of throwing fastballs by youth baseball pitchers results in force components consistent with proposed mechanisms for 2 clinical entities.

scholarly journals Decreased Shoulder External Rotation and Flexion are Greater Predictors of Injury than Internal Rotation Deficits: Analysis of 132 Pitcher-Seasons in Professional Baseball

2017 ◽  
Vol 5 (7_suppl6) ◽  
pp. 2325967117S0022
Author(s):  
Christopher L. Camp ◽  
Alec Sinatro ◽  
Andrea Spiker ◽  
Brian C. Werner ◽  
David W. Altchek ◽  
...  
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Professional Baseball ◽  
Shoulder External Rotation

scholarly journals Associations Among Hip and Shoulder Range of Motion and Shoulder Injury in Professional Baseball Players

2010 ◽  
Vol 45 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Steve Scher ◽  
Kyle Anderson ◽  
Nick Weber ◽  
Jeff Bajorek ◽  
Kevin Rand ◽  
...  
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Professional Baseball ◽  
Shoulder Injury ◽  
Baseball Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
History Of ◽  
Shoulder External Rotation ◽  
The Relationship ◽  
Hip Extension

Abstract Context: The overhead throwing motion is complex, and restrictions in range of motion (ROM) at the hip may place additional demands on the shoulder that lead to injury. However, the relationship between hip and shoulder ROM in athletes with and without a history of shoulder injury is unknown. Objective: To (1) determine if differences exist in hip and shoulder ROM between professional baseball players with a history of shoulder injury and those with no history of shoulder injury and (2) assess relationships between hip and shoulder ROM in these players. Design: Cross-sectional study. Patients or Other Participants: Fifty-seven professional baseball players. Main Outcome Measure(s): Outcome measures consisted of hip extension and internal rotation, shoulder internal and external rotation, glenohumeral internal-rotation deficit, and history of shoulder injury. Differences in shoulder and hip ROM were assessed with a 1-way analysis of variance. Associations between hip and shoulder ROM were assessed with linear regression. Results: Nonpitchers with a history of shoulder injury had more external rotation and less internal rotation of the shoulder than nonpitchers with no history of shoulder injury. Glenohumeral internal-rotation deficit was greater in both pitchers and nonpitchers with a history of shoulder injury. The relationship between dominant hip extension and shoulder external rotation was significant for pitchers with a history of shoulder injury and nonpitchers with a history of shoulder injury. Conclusions: Shoulder injury may be associated with specific measures of hip and shoulder ROM, and hip extension and shoulder external rotation may be related in baseball players with a history of shoulder injury. Additional research is necessary to understand the specific mechanisms of shoulder injury in the throwing athlete.

Pitching Mechanics and the Relationship to Accuracy in Professional Baseball Pitchers

2022 ◽  
pp. 036354652110678
Author(s):  
Joseph E. Manzi ◽  
Brittany Dowling ◽  
Zhaorui Wang ◽  
Andrew Luzzi ◽  
Ryan Thacher ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Internal Rotation ◽  
Injury Risk ◽  
Body Height ◽  
Knee Extension ◽  
High Accuracy ◽  
Professional Baseball ◽  
Significant Difference ◽  
The Absolute ◽  
Baseball Pitchers

Background: Biomechanical predictors of pitching accuracy are underevaluated in baseball research. It is unclear how pitchers with higher accuracy differ in terms of kinematics and upper extremity kinetics. Purpose: To differentiate high- and low-accuracy professional pitchers by full-body kinematic and upper extremity kinetic parameters. Study Design: Descriptive laboratory study. Methods: In total, 121 professional baseball pitchers threw 8 to 12 fastballs while assessed with motion-capture technology (480 Hz). Pitchers were divided into high-accuracy (n = 33), moderate-accuracy (n = 52), and low-accuracy (n = 36) groups based on the absolute center deviation of each pitcher’s average pitch to the center of the pitching chart by greater or less than 0.5 SD from the mean, respectively. The 95% confidence ellipses with comparisons of major and minor radii and pitching probability density grids were constructed. Analysis of variance was used to compare kinematic and kinetic values between groups. Results: The absolute center deviation (14.5% ± 6.7% vs 33.5% ± 3.7% grid width; P < .001) was significantly lower in the high-accuracy compared with the low-accuracy group, with no significant difference in ball velocity (38.0 ± 1.7 vs 38.5 ± 2.0 m/s; P = .222). Lead knee flexion at ball release (30.6°± 17.8° vs 40.1°± 16.3°; P = .023) was significantly less for the high-accuracy pitchers. Peak normalized shoulder internal rotation torque (5.5% ± 1.0% vs 4.9% ± 0.7% body weight [BW] × body height [BH]; P = .008), normalized elbow varus torque (5.4% ± 1.0% vs 4.8% ± 0.7% BW × BH; P = .008), and normalized elbow medial force (42.9% ± 7.3% vs 38.6% ± 6.2% BW; P = .024) were significantly greater for the low-accuracy group compared with the high-accuracy group. Conclusion: Professional pitchers with increased accuracy experienced decreased throwing arm kinetics. These pitchers had increased lead knee extension at later stages of the pitch, potentially providing more stable engagement with the ground and transference of kinetic energy to the upper extremities. Professional pitchers can consider increasing lead knee extension at the final stages of the pitch to improve the accuracy of their throws and mitigate elbow varus torque. Clinical Relevance: Increased elbow varus torque, shoulder internal rotation torque, and elbow medial force in less accurate pitchers may contribute to increased injury risk in this group.

Shoulder External Rotational Properties During Physical Examination Are Associated With Injury That Requires Surgery and Shoulder Joint Loading During Baseball Pitching

2021 ◽  
pp. 036354652110398
Author(s):  
Hannah Stokes ◽  
Koco Eaton ◽  
Naiquan (Nigel) Zheng
Keyword(s):  
Physical Examination ◽  
Range Of Motion ◽  
Internal Rotation ◽  
Shoulder Joint ◽  
External Rotation ◽  
Joint Loading ◽  
Arm Injuries ◽  
Shoulder External Rotation ◽  
Baseball Pitchers ◽  
Shoulder Flexibility

Background: Throwing arm injuries are common because of the demand on the shoulder. The shoulder is qualitatively checked regularly by team physicians. Excessive instability and joint loading in baseball pitching are risk factors for throwing arm injuries. Knowledge of shoulder flexibility, range of motion, and joint loading may provide new insights for treatments to reduce the likelihood of injury incidence. Purpose: To investigate the relationship among injuries, shoulder external rotational properties, and shoulder joint loading in baseball pitchers. Study Design: Descriptive laboratory study. Methods: Pitching kinetics, shoulder rotational tests, and self-reported injury questionnaires were used to study 177 collegiate baseball pitchers. Pitching motion data were collected at 240 Hz using a motion capture system. A custom program calculated the shoulder joint loading. The shoulder rotational test quantitatively records shoulder range of motion and flexibility using a custom-made wireless device. Self-reported injury questionnaires were filled out during tests and yearly follow-ups. The total length of the study was 5 years. Analysis of variance, chi-square, and regression tests were performed to compare differences among groups and detect correlations with surgery and shoulder joint loadings. Results: There were significant differences in shoulder flexibility among surgery groups. Shoulder external rotational properties during physical examination were significantly associated with shoulder joint loading in baseball pitching. High shoulder external rotation was associated with 14% to 36% lower shoulder posterior force and adduction, internal rotation, and horizontal adduction torque ( P < .05). High shoulder flexibility was associated with 13% higher anterior force ( P < .05). High shoulder external rotation before external rotation torque was applied was associated with 13% to 33% lower shoulder inferior force and adduction, internal rotation, and horizontal adduction torque ( P < .05). There were no significant differences in shoulder joint loading among the surgery groups. Conclusion: Shoulder injuries that require surgery were associated with shoulder external rotation flexibility. High shoulder external rotation may be advantageous because it lowers the force and torque on the shoulder joint. Clinical Relevance: The ability to understand shoulder external rotational properties, joint loading, and injury during baseball pitching helps further our understanding of injury mechanisms. The shoulder rotational test should be used as a screening tool to identify players at risk.

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