Glenohumeral motion deficits: friend or foe?
Level 5 - mechanism / opinion, no new human data
Narrative review and expert opinion proposing clinical diagnostic criteria without new empirical data.
What was done
This clinical review and conceptual commentary differentiates normal from pathologic glenohumeral internal rotation deficiency (GIRD) in overhead athletes based on internal rotation loss, total rotational motion (TROM), and external rotation deficiency (ERD).
What was found
The authors define anatomical GIRD (aGIRD) as an internal rotation loss of <18°–20° with symmetrical bilateral TROM, and pathologic GIRD (pGIRD) as an internal rotation loss >18°–20° with a bilateral TROM loss >5°. They note that external rotation deficiency (difference in external rotation between throwing and non-throwing shoulders <5°) and overall loss of TROM correlate with future shoulder injury. No original experimental data or statistical tests are reported in the abstract.
Why it matters
It provides specific rotational range-of-motion cutoffs to help clinicians distinguish normal sport-specific adaptations required for high-velocity throwing from pathologic deficits needing intervention.
Limits
This is a narrative framework and clinical opinion without original patient data, cohort follow-up, or primary statistical testing presented in the abstract.
Cited by
- context Normal shoulder rotational range of motion spans approximately 160 degrees.