Quantification of Anterior Translation of the Humeral Head in the Throwing Shoulder

2000 ◽  
Vol 28 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Todd S. Ellenbecker ◽  
Angelo J. Mattalino ◽  
Eric Elam ◽  
Roger Caplinger

Clinical evaluation of humeral head translation relies mainly on manual tests to measure laxity in the human shoulder. The purposes of this study were to determine whether side-to-side differences exist in anterior humeral head translation in professional baseball pitchers, to compare manual laxity testing with stress radiography for quantifying humeral head translation, and to test intrarater reliability of the manual humeral head translation and stress radiography tests. Twenty professional baseball pitchers underwent bilateral manual anterior humeral head translation and stress radiographic tests. Stress radiography was performed by imparting a 15-daN anterior load to the shoulder in 90° of abduction with both neutral and 60° of external rotation and recording the glenohumeral joint translation at rest and under stress in each position. Eight subjects were retested to assess the reliability of these methods. Results showed no significant difference between the dominant and nondominant extremity in the amount of anterior humeral head translation measured manually and with stress radiography, nor significant correlation between anterior humeral head translation measured manually and by stress radiography. Testretest reliability was moderate-to-poor for the manual humeral head translation test and moderate for stress radiography.

2007 ◽  
Vol 16 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Kim M. Clabbers ◽  
John D. Kelly ◽  
Dov Bader ◽  
Matthew Eager ◽  
Carl Imhauser ◽  
...  

Context:Throwing injuries.Objective:To study the effects of posterior capsule tightness on humeral head position in late cocking simulation.Design:Eight fresh frozen shoulders were placed in position of “late cocking,” 90 degrees abduction, and 10 degrees adduction and maximal external rotation. 3D measurements of humeral head relationship to the glenoid were taken with an infrared motion sensor, both before and after suture plication of the posterior capsule. Plications of 20% posterior/inferior capsule and 20% entire posterior capsule were performed, followed by plications of 40% of the posterior/inferior capsule and 40% entire posterior capsule.Setting:Cadaver Lab.Intervention:Posterior capsular placation.Main Outcome Measures:Humeral head position.Results:40%, but not 20%, posterior/inferior and posterior plications demonstrated a trend to increased posterior-superior humeral head translation relative to controls.Conclusion:Surgically created posterior capsular tightness of the glenohumeral joint demonstrated a nonsignificant trend to increased posterior/superior humeral head translation in the late cocking position of throwing.


2021 ◽  
Author(s):  
Daisuke Momma ◽  
Alejandro A Espinoza Orías ◽  
Tohru Irie ◽  
Tomoyo Irie ◽  
Eiji Kondo ◽  
...  

Abstract The purpose of this study is to evaluate the glenohumeral contact area, center of glenohumeral contact area, and center of humeral head during simulated pitching motion in collegiate baseball pitchers using four-dimensional computed tomography (4D CT). We obtained 4D CT data from the dominant and non-dominant shoulders of eight collegiate baseball pitchers during the cocking motion. CT image data of each joint were reconstructed using a 3D reconstruction software package. The glenohumeral contact area, center of glenohumeral contact area, center of humeral head, and oblateness of humeral head were calculated from 3D bone models using customized software. The center of glenohumeral contact area translated significantly from anterior to posterior during maximum external rotation to maximum internal rotation. The center of humeral head translated from posterior to anterior during maximum external rotation to maximum internal rotation. There was a high negative correlation between anterior translation of the center of glenohumeral contact area and center of humeral head, and a positive correlation between the translation and the oblateness. 4D CT analyses demonstrated that the center of humeral head translated in the opposite direction to that of the center of glenohumeral contact area during external rotation to internal rotation in abduction in the dominant and non-dominant shoulders. This diametric translation can be explained by the oblateness of the humeral head. 4D CT scanning and the software for bone surface modeling of the glenohumeral joint enabled quantitative assessment of glenohumeral micromotion and identified humeral head oblateness as the cause of diametric change.


2005 ◽  
Vol 33 (9) ◽  
pp. 1392-1399 ◽  
Author(s):  
Paul A. Borsa ◽  
Kevin E. Wilk ◽  
Jon A. Jacobson ◽  
Jason S. Scibek ◽  
Geoffrey C. Dover ◽  
...  

Background Altered mobility patterns in the throwing shoulders of professional baseball pitchers have been reported. Most published reports examining glenohumeral laxity have not used an objective testing device. Objective Quantify and compare glenohumeral translation and rotational range of motion between the throwing and non-throwing shoulders in professional baseball pitchers. Study Design Descriptive laboratory study. Methods Force-displacement and range of motion measures were performed bilaterally on 43 asymptomatic professional baseball pitchers. Ultrasound imaging was used to measure glenohumeral translations under stressed and unstressed conditions. Results No significant difference in translation was found between the throwing and nonthrowing shoulders. For both shoulders, posterior translation (5.38 ± 2.7 mm) was significantly greater (P < .001) than was anterior translation (2.81 ± 1.6 mm). External rotation in the throwing shoulder was significantly greater than that in the nonthrowing shoulder (P < .001), whereas internal rotation in the throwing shoulder was significantly less than that in the nonthrowing shoulder (P < .001). The total arc of rotation for the throwing shoulder was not significantly different than that for the nonthrowing shoulder, and correlation coefficients were poor between rotational and translational range of motion in the throwing shoulder, ranging from r = 0.232 to 0.209 between variables. Conclusion No significant difference in glenohumeral translation exists between the throwing and nonthrowing shoulders in asymptomatic professional baseball pitchers, posterior translation is significantly greater than anterior translation in the throwing shoulders of professional baseball pitchers, and glenohumeral translation is not related to rotational range of motion in the throwing shoulders of professional baseball pitchers. Clinical Relevance Altered mobility patterns in asymptomatic professional baseball pitchers may be due to factors other than capsular adaptive changes.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 759
Author(s):  
Byung Gon Kim ◽  
Seung Kil Lim ◽  
Sunga Kong

This study aims to assess the relationship between scapular upward rotation (SUR) across varying humeral-elevation angles (HEAs) and shoulder isokinetic strength and ratio in professional baseball pitchers. The subjects were professional baseball pitchers (n = 16) without a history of shoulder injury in the last six months. The subject’s SUR angles were measured with the humerus elevated at HEAs of 0° (at rest), 60°, 90°, and 120° to the scapular plane. Shoulder isokinetic strength was evaluated for shoulder internal rotation (IR) and external rotation (ER) strength (PT%BW and TW%BW), and the ER/IR strength ratios were determined at 60, 120 and 180°/s using an isokinetic dynamometer. The SUR angle at an HEA of 0° was positively correlated with IR strength at 120°/s (r = 0.535) and 180°/s (r = 0.522). The SUR angle at an HEA of 60° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.505) and 120°/s (r = −0.500). The SUR angle at an HEA of 90° was negatively correlated with the ER/IR strength ratios at 60°/s (r = −0.574; r = −0.554) and 120°/s (r = −0.521; r = −0.589) as well as with ER strength at 180°/s (r = −0.591, r = −0.556). The SUR angle at an HEA of 120° was negatively correlated with ER strength at 60°/s (r = −0.558), 120°/s (r = −0.504; r = −0.524), and 180°/s (r = −0.543) and the ER/IR strength ratio at 60°/s (r = −0.517). In this study, we found that the ratio of isokinetic strength between ER and IR became closer to the normal range on increasing the SUR angle. In particular, an HEA of 90°, which resembles the pitching motion, showed a clear relationship between SUR, shoulder ER, and the ratio of ER/IR isokinetic strength in professional baseball pitchers.


2018 ◽  
Vol 47 (2) ◽  
pp. 165
Author(s):  
Lana Hirai Gimber ◽  
Mihra S. Taljanovic ◽  
Zachary A. Rockov ◽  
Elizabeth A. Krupinski ◽  
Tyson S. Chadaz ◽  
...  

<p><strong>Objective.</strong> To describe a new radiographic sign, “veil of obscuration”, associated with posterior glenohumeral joint (shoulder) dislocations and determine its incidence and validity compared to other known classic radiographic signs.</p><p><strong>Methods.</strong> Four-year retrospective study identified 30 acute posterior shoulder dislocation patients. Radiographs reviewed in consensus by 2 musculoskeletal radiologists for the “veil of obscuration”, seen on AP shoulder radiographs and representing a comminuted fracture of the lesser tuberosity projecting over the humeral head or glenohumeral joint. Incidence of this radiographic sign of posterior glenohumeral joint dislocation in addition to other previously described classic radiographic signs, and association with other fractures, surgery, and mechanism of injury were evaluated. Continuous data was analysed with student t-test and categorical data with Chi-Square test.</p><p><strong>Results. </strong>There were 20 right and 10 left posterior shoulder dislocations. Majority of injuries resulted from vehicle crash (44%). In most cases, reverse Hill-Sachs lesion (83%) and fixed internal rotation of the humeral head (76%) were present, followed by trough line (43%) and “veil of obscuration” (40%). Trough line was seen in significantly more major trauma and vehicle crashes (78% and 46%; P=0.015), while “veil of obscuration” was seen in more seizures (86%; P=0.037) and in all surgical patients.  No significant difference in presence of other classic radiographic signs in regards to surgery.</p><p><strong>Conclusion. </strong>The newly described radiographic sign of posterior shoulder dislocations named the “veil of obscuration” has comparable incidence as other classic radiographic signs and may be useful in the recognition and diagnosis of these injuries.</p>


2019 ◽  
Vol 7 (11_suppl6) ◽  
pp. 2325967119S0046
Author(s):  
Troydimas Panjaitan

The shoulder is one of the most complex joints of the human body. Consequently, they are susceptible to injury and degeneration. Mechanical shoulder pathology typically results when overuse, extremes of motion, or excessive forces overwhelm intrinsic material properties of the shoulder complex resulting in tears of the rotator cuff, capsule, and labrum. The fundamental central component of the shoulder complex is the glenohumeral joint. It has a ball-and-socket configuration with a surface area ratio of the humeral head to glenoid fossa of about 3:1 with an appearance similar to a golf ball on a tee. Overall, there is minimal bony covering and limited contact areas that allow extensive translational and rotational ability in all three planes. The glenohumeral joint has 2 groups of stabilizers, which are static (passive) and dynamic (active) restrains. Static stabilizers include the concavity of the glenoid fossa, glenoid fossa retroversion and superior angulation, glenoid labrum, the joint capsule, and glenohumeral ligaments, and a vacuum effect from negative intra-articular pressure. Dynamic stabilization is merely the coordinated contraction of the rotator cuff muscles that create forces that compress the articular surfaces of the humeral head into the concave surface of the glenoid fossa. During upper extremity movement, the effects of static stabilizers are minimized and dynamic or active stabilizers become the dominant forces responsible for glenohumeral stability The simple act of arm elevation is a complex task that occurs via the combination of glenohumeral and scapulothoracic motion, together known as scapulohumeral rhythm. In the first 1200, glenohumeral arm abduction, the supraspinatus and deltoid work together and create a force couple that promotes stability, while raising the arm (deltoid contraction). In addition, the humerus must undergo 450 external rotation to not only clear the greater tuberosity posteriorly but also loosen the inferior glenohumeral ligament (IGHL) to allow maximum elevation. There are several anatomical updates regarding the rotator cuff and capsular footprint. The footprint of the supraspinatus on the greater tuberosity is much smaller than previously believed, and this area of the greater tuberosity is actually occupied by a substantial amount of the infraspinatus. The superior-most insertion of the subscapularis tendon extends a thin tendinous slip, which attaches to the fovea capitis of the humerus. The teres minor muscle inserts to the lowest impression of the greater tuberosity of the humerus and additionally inserts to the posterior side of the surgical neck of the humerus.


2007 ◽  
Vol 35 (8) ◽  
pp. 1371-1376 ◽  
Author(s):  
Todd S. Ellenbecker ◽  
Gail A. Ellenbecker ◽  
E. Paul Roetert ◽  
Rogerio Teixeira Silva ◽  
Greg Keuter ◽  
...  

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.


2021 ◽  
pp. 194173812098001
Author(s):  
T. David Luo ◽  
Aaron D. Sciascia ◽  
Austin V. Stone ◽  
Chukwuweike U. Gwam ◽  
Christopher A. Grimes ◽  
...  

Background: Repetitive throwing in baseball pitchers can lead to pathologic changes in shoulder anatomy, range of motion (notably glenohumeral internal rotation deficit), and subsequent injury; however, the ideal strengthening, recovery, and maintenance protocol of the throwing shoulder in baseball remains unclear. Two strategies for throwing shoulder recovery from pitching are straight-line long-toss (SLT) throwing and ultra-long-toss (ULT) throwing, although neither is preferentially supported by empirical data. Hypothesis: ULT will be more effective in returning baseline internal rotation as compared with SLT in collegiate pitchers after a pitching session. Study Design: Cohort study. Level of Evidence: Level 3. Methods: A total of 24 National Collegiate Athletic Association Division I baseball pitchers with mean age 20.0 ± 1.1 years were randomized to either the ULT group (n = 13; 9 right-hand dominant, 4 left-hand dominant) or SLT group (n = 11; 10 right-hand dominant, 1 left-hand dominant). Measurements (dominant and nondominant, 90° abducted external rotation [ER], internal rotation [IR], and total range of motion [TROM]) were taken at 5 time points across 3 days: before and immediately after a standardized bullpen session on day 1; before and immediately after a randomized standardized ULT or SLT session on day 2; and before practice on Day 3. Results: ULT demonstrated significantly greater final ER compared with baseline (+10°; P = 0.05), but did not demonstrate significant IR changes. Similarly, SLT demonstrated significantly greater post-SLT ER (+12°; P = 0.02) and TROM (+12°; P = 0.01) compared with baseline, but no significant IR changes. Final ER measurements were similar between ULT (135° ± 14°) and SLT (138° ± 10°) ( P = 0.59). There was also no statistically significant difference in final IR between ULT (51° ± 14°) and SLT (56° ± 8°) ( P = 0.27). Conclusion: The routine use of postperformance, ULT throwing to recover from range of motion alterations, specifically IR loss, after a pitching session is not superior to standard, SLT throwing. Based on these findings, the choice of postpitching recovery throwing could be player specific based on experience and comfort. Clinical Relevance: The most effective throwing regimens for enhancing performance and reducing residual impairment are unclear, and ideal recovery and maintenance protocols are frequently debated with little supporting data. Two strategies for throwing shoulder recovery from pitching are SLT and ULT throwing. These are employed to help maintain range of motion and limit IR loss in pitchers. The routine use of ULT throwing for recovery and to limit range of motion alterations after a pitching session is not superior to SLT throwing.


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