Relationship Between Glenohumeral Internal Rotation Deficit and Medial Elbow Torque in High School Baseball Pitchers

2019 ◽  
Vol 47 (12) ◽  
pp. 2821-2826 ◽  
Author(s):  
D. Grace Smith ◽  
Alexander J. Swantek ◽  
Caleb M. Gulledge ◽  
Vincent A. Lizzio ◽  
Angel Bermudez ◽  
...  
Keyword(s):  
High School ◽  
Internal Rotation ◽  
Principal Component ◽  
Baseball Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
Ball Velocity ◽  
Maximum Effort ◽  
Baseball Pitchers ◽  
The Difference ◽  
Relative Differences

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.

scholarly journals Physical contributors to glenohumeral internal rotation deficit in high school baseball players

2015 ◽  
Vol 4 (3) ◽  
pp. 299-306 ◽  
Author(s):  
Elizabeth E. Hibberd ◽  
Casey E. Shutt ◽  
Sakiko Oyama ◽  
J. Troy Blackburn ◽  
Joseph B. Myers
Keyword(s):  
High School ◽  
Internal Rotation ◽  
Baseball Players ◽  
Glenohumeral Internal Rotation Deficit

scholarly journals Internal Rotation and Scapular Position Differences: A Comparison of Collegiate and High School Baseball Players

2010 ◽  
Vol 45 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Stephen J. Thomas ◽  
Kathleen A. Swanik ◽  
Charles B. Swanik ◽  
John D. Kelly
Keyword(s):  
High School ◽  
Internal Rotation ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Scapular Dyskinesis ◽  
Position Change ◽  
Baseball Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
Rotator Cuff Injuries ◽  
Collegiate Baseball

Abstract Context: Conditions such as labral and rotator cuff injuries have been linked with decreases in glenohumeral internal-rotation and increases in external-rotation motion. Also, decreased glenohumeral internal rotation is strongly associated with scapular dyskinesis. Objective: To compare healthy collegiate and high school baseball players' glenohumeral joint range of motion and scapular position. Design: Cross-sectional study. Setting: Institutional research laboratory. Patients or Other Participants: Thirty-one male National Collegiate Athletic Association Division I collegiate (age  =  20.23 ± 1.17 years, height  =  186.24 ± 5.73 cm, mass  =  92.01 ± 7.68 kg) and 21 male high school baseball players (age  =  16.57 ± 0.76 years, height  =  180.58 ± 6.01 cm, mass  =  79.09 ± 11.51 kg). Main Outcome Measure(s): Glenohumeral internal and external rotation and scapular upward rotation were measured with a digital inclinometer. Scapular protraction was measured with a vernier caliper. All variables except scapular upward rotation were calculated as the difference between the dominant and nondominant sides. Results: Collegiate baseball players had more glenohumeral internal-rotation deficit (4.80°, P  =  .028) and total motion deficit (5.73°, P  =  .009) and less glenohumeral external-rotation gain (3.00°, P  =  .028) than high school players. Collegiate baseball players had less scapular upward rotation than high school players at the 90° (4.12°, P  =  .015, versus 3.00°, P  =  .025) and 120° (4.00°, P  =  .007, versus 3.40°, P  =  .005) positions. The scapular protraction difference was greater in collegiate baseball players than in high school players in the hands-on-hips and 90° positions (0.77 cm, P  =  .021, and 1.4 cm, P  =  .001). Conclusions: When comparing high school with collegiate baseball players, these data suggest that glenohumeral internal-rotation deficit and scapular position change as the level of competition increases.

Baseball Pitchers’ Perceived Effort Does Not Match Actual Measured Effort During a Structured Long-Toss Throwing Program

2019 ◽  
Vol 47 (8) ◽  
pp. 1949-1954 ◽  
Author(s):  
Heath P. Melugin ◽  
Dirk R. Larson ◽  
Glenn S. Fleisig ◽  
Stan Conte ◽  
Stephen A. Fealy ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Physical Therapists ◽  
Intraclass Correlation ◽  
Baseball Players ◽  
Perceived Effort ◽  
Ball Velocity ◽  
Collegiate Baseball ◽  
Maximum Effort ◽  
Male High School ◽  
Baseball Pitchers

Background: During rehabilitation throwing programs, baseball players are commonly asked to throw at reduced levels of effort (ie, 50% effort, 75% effort, etc) to moderate stress to healing tissues. It is currently unknown how changes in players’ perceived exertion compares with changes in actual exertion during structured long-toss programs. Purpose: To determine whether decreased effort correlates with decreased throwing metrics, whether metrics decrease proportionally with reductions in perceived effort, and to quantify intrathrower variability. Study Design: Descriptive laboratory study. Methods: Sixty male high school and collegiate baseball pitchers participated in a structured throwing program. A motusBASEBALL sleeve was worn by all players, which measured elbow varus torque, arm velocity, arm slot, and shoulder rotation. Ball velocity was measured with a radar gun. Each pitcher threw 5 throws a distance of 120 ft with 3 efforts: maximum effort, 75% effort, and 50% effort. Throwing metrics were compared among the 3 levels of effort to see if each 25% decrease resulted in proportional decreases in elbow varus torque and ball velocity. Intrathrower variability was determined for each throwing metric at each degree of effort. Results: All throwing metrics decreased as players decreased their perceived effort ( P < .001). However, these observed decreases were much smaller in magnitude than the decreases in perceived effort. During the 75% effort throws, elbow varus torque was only reduced to 93% of maximum and velocity dropped to 86% of maximum. Similarly, for the 50% effort throws, elbow varus torque remained 87% of max effort torque, while velocity remained 78% of max. Intrathrower reliability was considered excellent for most metrics (intraclass correlation coefficient, >0.75). Conclusion: For every 25% decrease in perceived effort, elbow varus torque only decreased 7% and velocity only decreased 11%. Thus, when players throw at what they perceive to be reduced effort, their actual throwing metrics do not decrease at the same rate as their perceived exertion. Clinical Relevance: Measured effort decreased with decreasing perceived effort, but these were not proportional. This has significant implications for physical therapists, physicians, trainers, coaches, and athletes to understand and monitor elbow stress during the rehabilitation process.

scholarly journals Effects of Mound Versus Flat-Ground Pitching and Distance on Arm Mechanics and Elbow Torque in High School Pitchers

2020 ◽  
Vol 8 (12) ◽  
pp. 232596712096924
Author(s):  
Brittany Dowling ◽  
Kathryn D. McElheny ◽  
Christopher L. Camp ◽  
Daphne I. Ling ◽  
Joshua S. Dines
Keyword(s):  
High School ◽  
Mixed Effects Models ◽  
Multivariable Model ◽  
Linear Mixed Effects ◽  
Study Results ◽  
Ball Velocity ◽  
Surrogate Measure ◽  
Baseball Pitchers ◽  
The Impact ◽  
Flat Ground

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.

scholarly journals Variability in Baseball Throwing Metrics During A Structured Long-toss Program: Does One Size Fit All?

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0039
Author(s):  
Nels Leafblad ◽  
Dirk Larson ◽  
Glenn S. Fleisig ◽  
Stan Conte ◽  
Stephen Fealy ◽  
...  
Keyword(s):  
High School ◽  
Laboratory Study ◽  
Coefficient Of Variation ◽  
Wearable Technology ◽  
Ball Velocity ◽  
Maximum Effort

Objectives: The variability of throwing metrics, particularly elbow torque and ball velocity, during structured long-toss programs is yet to be fully elucidated. The primary aims of this study were to assess various throwing metrics through a structured long-toss program using wearable technology and to quantify the intra and inter thrower variability of these metrics at each stage of throwing. Methods: This was a descriptive laboratory study in which 60 high school and collegiate pitchers participated in a predetermined, structured, progressive long-toss program. All players wore a motusBASEBALL sleeve (Motus Global, Inc.; Rockville Centre, NY), which measured arm slot, arm velocity, shoulder rotation, and elbow varus torque. Radar guns were used to measure ball velocity. These metrics were compared within and between all pitchers at each of the following throwing distances: 90 ft, 120 ft, 150 ft, 180 ft, and maximum effort mound pitching. Intra- and inter- thrower reliabilities were calculated for each throwing metric at every stage of the program. Excellent intra-thrower reliability was defined by an Intra-class coefficient (ICC) >0.750. Acceptable inter-thrower reliability was defined by a Coefficient of Variation (CV) <5%. Results: Ball velocity significantly changed at each progressive throwing distance, but this did not consistently correlate with an increase in elbow torque. Pitching from the mound did not place more torque on the elbow than throwing from 120 ft and beyond. Intra-thrower reliability was excellent throughout the progressive long-toss program for each throwing metric. Ninety-one percent of throwers had acceptable inter-thrower reliability for ball velocity, whereas only 79% of throwers had acceptable inter-thrower reliability for elbow torque. Conclusion: Based on trends in elbow torque, it may be practical to incorporate pitching from the mound earlier in the program (once a player is comfortable throwing from 120 ft). Ball velocity and elbow torque do not necessarily correlate with one another, so a degree of caution should be exercised when using radar guns to estimate elbow torque. Given the variability in elbow torque between throwers, some athletes would likely benefit from an individualized throwing program.

Measurement of Glenohumeral Internal Rotation in Asymptomatic Tennis Players and Swimmers

2009 ◽  
Vol 37 (5) ◽  
pp. 1017-1023 ◽  
Author(s):  
Renato Rangel Torres ◽  
João Luiz Ellera Gomes
Keyword(s):  
Internal Rotation ◽  
External Rotation ◽  
Control Group ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Tennis Players ◽  
Glenohumeral Internal Rotation Deficit ◽  
Significant Difference ◽  
Overhead Sports ◽  
The Difference

Background Glenohumeral internal rotation deficit, often diagnosed in players of overhead sports, has been associated with the development of secondary shoulder lesions. Hypothesis Asymptomatic players of different overhead sports will exhibit variable degrees of glenohumeral internal rotation deficit. Study Design Cross-sectional study; Level of evidence, 3. Methods Fifty-four asymptomatic male volunteers (108 shoulders) divided into 3 groups (tennis players, swimmers, control group) underwent measurements of glenohumeral internal and external rotation using clinical examination with scapular stabilization. Measurements of dominant and nondominant shoulders were compared within and between groups. Glenohumeral internal rotation deficit (GIRD) was defined as the difference in internal rotation between the nondominant and dominant shoulders. Results In tennis players, mean GIRD was 23.9° ± 8.4° (P < .001); in swimmers, 12° ± 6.8° (P < .001); and in the control group, 4.9° ± 7.4° (P = .035). Dominant shoulders showed significant difference between all groups, and the difference in internal rotation of the dominant shoulder between the group of tennis players in comparison with the control group (27.6°, P < .001) was greater than the difference in internal rotation of the dominant shoulder found in the group of swimmers compared with the control group (17.9°, P < .001). Between tennis players and swimmers, the difference in internal rotation of the dominant shoulder was 9.7° (P = .002). Conclusion Dominant limbs showed less glenohumeral internal rotation than the nondominant limbs in all groups, with the deficit in the group of tennis players about twice the deficit found for swimmers. Mean difference between limbs in the control group was less than 5°, which is within normal parameters according to most studies. There were statistically significant differences between all groups when dominant shoulders were compared with each other, differences that were not compensated by external rotation gain. Tennis players had the least range of motion, followed by swimmers.

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