Humeral retrotorsion corrected glenohumeral external rotation deficits are present in medial ulnar collateral ligament injured and uninjured college baseball players

Sep 28, 2026

Uploaded by Aria

Background: Glenohumeral rotational motion should be interpreted within relative humeral retrotorsion (rHRT). No prior study examined shoulder rotational motion in the rHRT context for a medial ulnar collateral ligament (MUCL)-injured population. Purpose: Determine whether differences exist in HRT-corrected rotational motion between MUCL-injured and uninjured college baseball players. Methods: Thirty-five MUCL-injured players were matched with 35 uninjured controls, measuring external and internal rotation and anatomic HRT on both arms.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages10

Reading Time25 min

AccessFree to download

Background

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J S E S I N T E R N A T I O N A L 1 0 ( 2 0 2 6 ) 1 0 1 3 9 8 Available online [at](at www.sciencedirect.com)[ www.sciencedirect.com](at www.sciencedirect.com) ScienceDirect [www.jsesinternational.org](www.jsesinternational.org) Humeral retrotorsion corrected glenohumeral external rotation deficits are present in medial ulnar collateral ligament injured and uninjured college baseball players Jacob E. Vasquez, PT, DPT, OCSa, Frankie-Ann McCauley, PT, DPT, SCS, CSCSa, Claire M. Reynolds, PT, DPT, SCSa, Sean M. Kennedy, PT, DPT, PhD, SCS, CSCSb, Jacob D. Jelmini, PhD, ATC, CSCSa, Zachary A. Gehringc, J. Craig Garrison, PT, PhD, SCS, ATCa, John E. Conway, MDc, and Natalie L. Myers, PhD, ATC, PESd, * aMemorial Hermann Health, Rockets Sports Medicine Institute, Houston, TX, USA bAdventHealth Sports Med and Rehab, Orlando, FL, USA cUniversity of Texas Health Sciences Center, McGovern School of Medicine, Houston, TX, USAdATI Physical Therapy, Institute for Musculoskeletal Advancement, Downers Grove, IL, USA A R T I C L E I N F O Keywords: Baseball Shoulder Humeral retrotorsion Rotational motion Deficit Retrotorsion corrected motion A B S T R A C T Background: Glenohumeral rotational motion should be interpreted within the context of relative humeral retrotorsion (rHRT). To date, no study has investigated shoulder rotational motion within the context of rHRT in a medial ulnar collateral ligament (MUCL)—injured population. Therefore, the purpose of this study was to determine if there were differences in HRT-corrected rotational motion between MUCL-injured and uninjured college baseball players. Methods: Thirty-five baseball players diagnosed with an MUCL injury were matched with 35 uninjured controls. Glenohumeral external rotation (GER) and internal rotation (GIR), as well as anatomic HRT, were collected on both arms. Data reduction was performed for all objective All injured participants read and signed an electronic informed consent form approved by The University of Texas Health Science Center at Houston (IRB approval \#:HSC-MH-21-1041) prior to enrollment in the study. All uninjured participants read and signed an electronic informed consent form approved by The University of Texas Health Science Center at Houston (IRB approval \#:HSC-MH-22-0537) prior to enrollment in the study. *Corresponding author: Natalie L. Myers, PhD, ATC, PES, ATI Physical Therapy, Institute for Musculoskeletal Advancement, 2001 Butterfield Rd, Suite 1600, Downers Grove, IL 60515, USA. E-mail address: [nmyers02@gmail.com](nmyers02@gmail.com) (N.L. Myers) . [https://doi.org/10.1016/j.jseint.2025.10.001](https://doi.org/10.1016/j.jseint.2025.10.001) 2666-6383/© 2025 The Author(s) . Published by Elsevier Inc. on behalf of American Shoulder and Elbow Surgeons. This is an open access article under the CC BY-NC-ND license ([http://creativecommons.org/licenses/by-nc-nd/4.0/](http://creativecommons.org/licenses/by-nc-nd/4.0/)) . rotational motions and anatomic HRT, which was used to quantify rHRT. rHRT was then used to calculate HRT-corrected GER and HRT-corrected GIR. Outcomes were compared between groups using multivariate analysis of covariance, controlling for baseline cohort differences. Results: Results indicated no significant multivariate effects of cohort, body mass index, or level of competition on HRT-corrected GER or GIR (all Pillai's Trace P > .05, partial η2 ≤ 0.019) . Adjusted estimated marginal means for HRT-corrected GER were —9.99◦(standard error [SE] = 2. 51) for the MUCL cohort and —5.45◦ (SE = 2. 51) for the uninjured cohort; for HRT-corrected GIR, they were 5.01◦ (SE = 2.46) and 2.21◦ (SE = 2.46), respectively. Conclusion: HRT-corrected GER deficits are more prevalent than HRT-corrected GIR deficitsin both cohorts. These findings continue to highlight the importance of accounting for osseous adaptations in range of motion measurements, as GIR deficit is not as common as previously thought. Lev

FAQs

What is the study’s main purpose regarding rHRT and shoulder motion?

To determine whether HRT-corrected rotational motion differs between MUCL-injured and uninjured college baseball players using relative humeral retrotorsion as the interpretive context.

How were participants grouped and what measurements were collected?

Thirty-five baseball players with MUCL injury were matched with 35 uninjured controls. Glenohumeral external and internal rotation and anatomic HRT were collected on both arms.

What did the results show about HRT-corrected external versus internal rotation deficits?

HRT-corrected external rotation (GER) deficits were more prevalent than HRT-corrected internal rotation (GIR) deficits in both groups, with no significant multivariate effects across cohorts on the corrected measures.

Why are the findings clinically important for range of motion assessment?

They emphasize accounting for osseous adaptations when interpreting range of motion measurements, because GIR deficits are less common than previously thought.

Sep 28, 2026

Uploaded by Aria