scholarly journals Association of Pitch Timing and Throwing Arm Kinetics in High School and Professional Pitchers

2021 ◽  
Vol 49 (12) ◽  
pp. 3386-3394
Author(s):  
Joseph E. Manzi ◽  
Brittany Dowling ◽  
Zhaorui Wang ◽  
Kyle N. Kunze ◽  
Jennifer Estrada ◽  
...  

Background: Understanding the relationship between the temporal phases of the baseball pitch and subsequent joint loading may improve our understanding of optimal pitching mechanics and contribute to injury prevention in baseball pitchers. Purpose: To investigate the temporal phases of the pitching motion and their associations with ball velocity and throwing arm kinetics in high school (HS) and professional (PRO) baseball pitchers. Study Design: Descriptive laboratory study. Methods: PRO (n = 317) and HS (n = 54) baseball pitchers were evaluated throwing 8 to 12 fastball pitches using 3-dimensional motion capture (480 Hz). Four distinct phases of the pitching motion were evaluated based on timing of angular velocities: (1) Foot-Pelvis, (2) Pelvis-Torso, (3) Torso-Elbow, and (4) Elbow-Ball. Peak elbow varus torque, shoulder internal rotation torque, and shoulder distraction force were also calculated and compared between playing levels using 2-sample t tests. Linear mixed-effect models with compound symmetry covariance structures were used to correlate pitch velocity and throwing arm kinetics with the distinct temporal phases of the pitching motion. Results: PRO pitchers had greater weight and height, and faster ball velocities than HS pitchers ( P < .001). There was no difference in total pitch time between groups ( P = .670). PRO pitchers spent less time in the Foot-Pelvis ( P = .010) and more time in the Pelvis-Torso ( P < .001) phase comparatively. Shorter time spent in the earlier phases of the pitching motion was significantly associated with greater ball velocity for both PRO and HS pitchers (Foot-Pelvis: B = −6.4 and B = −11.06, respectively; Pelvis-Torso: B = −6.4 and B = −11.4, respectively), while also associated with increased shoulder proximal force (Pelvis-Torso: B = −76.4 and B = −77.5, respectively). Decreased time in the Elbow-Ball phase correlated with greater shoulder proximal force for both cohorts (B = −1150 and B = −645, respectively) with no significant correlation found for ball velocity. Conclusion: Significant differences in temporal phases exist between PRO and HS pitchers. For all pitchers, increased time spent in the final phase of the pitching motion has the potential to decrease shoulder distraction force with no significant loss in ball velocity. Clinical Relevance: Identifying risk factors for increased shoulder and elbow kinetics, acting as a surrogate for loading at the respective joints, has potential implications in injury prevention.

2020 ◽  
Vol 8 (12) ◽  
pp. 232596712096924
Author(s):  
Brittany Dowling ◽  
Kathryn D. McElheny ◽  
Christopher L. Camp ◽  
Daphne I. Ling ◽  
Joshua S. Dines

Background: Although the monitoring of a pitcher’s throwing arm workload has become a hot topic in both research and the pitching world, the impact of mound height and distance still remains unclear. Purpose: To compare the kinetics and kinematics between pitches from a mound and flat ground at 2 different distances. Study Design: Descriptive laboratory study. Methods: A total of 21 healthy high school varsity baseball pitchers (age, 16.2 ± 1.3 years; weight, 73.6 ± 11.0 kg; height, 181.3 ± 6.4 cm) participated in this study. Players were fitted with a motusBASEBALL sensor and sleeve. Each pitcher was instructed to pitch 5 fastballs under 4 conditions: mound at 60.5 ft (regulation distance), flat ground at 60.5 ft, mound at 50.5 ft, and flat ground at 50.5 ft. Linear mixed-effects models were used to account for both intra- and interplayer variability. A multivariable model was used to evaluate the association of mound pitching, flat-ground pitching, and their distances (50.5 ft and 60.5 ft), and their interaction to arm speed, arm slot, arm rotation, elbow varus torque, and ball velocity. Results: There were no statistically significant effects of mound, flat-ground, or distance variation on arm speed or shoulder rotation. Arm slot was significantly higher (+3.0°; P = .02) on pitches from the mound at 60.5 ft compared with 50.5 ft. Elbow varus torque was lower (–1.5 N·m; P = .02) on mound pitches at 60.5 ft compared with 50.5 ft. Pitches thrown from the mound displayed significantly faster ball velocity compared with flat-ground pitches at both distances ( P < .01 for both), with pitches at 60.5 ft having higher velocity (+0.7 m/s; P < .01). Conclusion: Contrary to long-standing notions, the study results suggest that pitching from the mound does not significantly increase stress on the elbow compared with flat-ground pitching. Lower elbow varus torque and faster ball velocity at the regulation distance compared with the reduced distance indicate that elbow stress and ball velocity may not correlate perfectly, and radar guns may not be an appropriate surrogate measure of elbow varus torque. Clinical Relevance: A better understanding of the kinetic and kinematic implications of various throwing programs will allow for the designing of programs that are driven by objective data with aims directed toward injury prevention and rehabilitation in baseball pitchers.


2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0042
Author(s):  
Donna Moxley Scarborough ◽  
Shannon E. Linderman ◽  
Javier E. Sanchez ◽  
Eric M. Berkson

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.


2015 ◽  
Vol 50 (6) ◽  
pp. 629-633 ◽  
Author(s):  
Eric G. Post ◽  
Kevin G. Laudner ◽  
Todd A. McLoda ◽  
Regan Wong ◽  
Keith Meister

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.


2014 ◽  
Vol 25 (1) ◽  
pp. 21-29
Author(s):  
김성용 ◽  
송홍선 ◽  
박종철 ◽  
Ji-Tae Kim

2005 ◽  
Vol 33 (11) ◽  
pp. 1716-1722 ◽  
Author(s):  
Michelle B. Sabick ◽  
Young-Kyu Kim ◽  
Michael R. Torry ◽  
Michael A. Keirns ◽  
Richard J. Hawkins

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.


2020 ◽  
Vol 36 (2) ◽  
pp. 68-75 ◽  
Author(s):  
Micheal J. Luera ◽  
Brittany Dowling ◽  
Tyler W.D. Muddle ◽  
Nathaniel D.M. Jenkins

Pitch velocity (PV) is important for pitching success, and the pelvis and trunk likely influence pitch performance. The purposes of this study were to examine the differences in pelvis and trunk kinetics and kinematics in professional baseball pitchers who throw at lower versus higher velocities (HVPs) and to examine the relationships among pelvis and trunk kinetics and kinematics and PV during each phase of the pitch delivery. The pitch velocity, pelvis and trunk peak angular velocities, kinetic energies and torques, and elbow and shoulder loads were compared among HVPs (n = 71; PV ≥ 40.2 m/s) and lower velocities pitchers (n = 78; PV < 39.8 m/s), as were trunk and pelvis rotation, flexion, and obliquity among 7 phases of the pitching delivery. Relationships among the kinetic and kinematic variables and PVs were examined. Higher velocity pitchers achieved greater upper trunk rotation at hand separation (+7.2°, P < .001) and elbow extension (+5.81°, P = .002) and were able to generate greater upper trunk angular velocities (+36.6 m/s, P = .01) compared with lower velocity pitcher. Trunk angular velocity (r = .29) and upper trunk rotation at hand separation (r = .18) and foot contact (r = .17) were weakly related to PV. Therefore, HVPs rotate their upper trunk to a greater degree during the early phases of the pitching motion and subsequently generate greater trunk angular velocities and PV.


2019 ◽  
Vol 47 (12) ◽  
pp. 2821-2826 ◽  
Author(s):  
D. Grace Smith ◽  
Alexander J. Swantek ◽  
Caleb M. Gulledge ◽  
Vincent A. Lizzio ◽  
Angel Bermudez ◽  
...  

Background: Alterations in throwing mechanics have been identified as a risk factor for overuse injuries in baseball players. Glenohumeral internal rotation deficit (GIRD) has been found to adversely affect throwing mechanics, but the effect of GIRD on medial elbow torque is unclear. Purpose: To investigate the relationship between GIRD and medial elbow torque in high school–aged baseball pitchers. Study Design: Descriptive laboratory study. Methods: High school baseball pitchers (14-18 years old) were recruited for participation in this study. Players’ height, weight, body mass index, and arm measurements were recorded as well as shoulder and elbow range of motion measurements. GIRD was calculated from the difference between dominant and nondominant shoulder internal rotation. Participants then pitched 5 fastballs at maximum effort while wearing a wireless sensor that recorded elbow torque, arm slot, arm speed, shoulder rotation, and ball velocity. Principal component analysis was performed to determine which variables were associated with elbow torque or ball velocity. Results: Twenty-three high school pitchers participated in this study; 35% (n = 8) of participants exhibited GIRD of at least 20°. The mean GIRD was 15.3°± 11.2° and was not a predictor of medial elbow torque ( P = .205) or ball velocity ( P = .333). Ball velocity, age, and height were predictors of medial elbow torque ( P = .012, P = .003, and P = .024, respectively). Conclusion: In high school baseball pitchers, GIRD was not associated with medial elbow torque during the pitching motion. Instead, ball velocity, player age, and player height carried greater significance. Clinical Relevance: This study suggests that high school pitchers with GIRD do not have an inherently greater risk for increased medial elbow torque during the throwing motion. It is recommended that pitchers instead assess their ball velocity to evaluate for relative differences in medial elbow torque.


2021 ◽  
pp. 175857322110103
Author(s):  
Joseph E Manzi ◽  
Brittany Dowling ◽  
Nicolas Trauger ◽  
Michael C Fu ◽  
Benjamin R Hansen ◽  
...  

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.


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