Execution
- 1Position the patient supine with the shoulder abducted to 90° and the elbow flexed to 90°.
- 2Stabilize the scapula manually or by controlling the coracoid / scapula so scapular winging does not add false internal rotation.
- 3Passively internally rotate the humerus and stop when the scapula begins to lift or move.
- 4Measure internal rotation with a goniometer or inclinometer and repeat external rotation measurement in the same stabilized position.
- 5Compare internal rotation deficit, external rotation gain, and total rotational motion with the opposite shoulder.
Positive outcome
GIRD is commonly considered present when internal rotation is reduced by about 18° to 20° or more compared with the opposite shoulder. Magee also notes that side-to-side GIRD should generally be 20° or less, and that total rotational motion should be closely compared between sides. A GIRD / GERG ratio greater than 1 increases concern in overhead athletes.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Awan et al. (2002) | NA | NA | NA | NA | NA |
| Wilk et al. (2011) | NA | NA | NA | NA | NA |
| Wilk et al. (2015) | NA | NA | NA | NA | NA |
CommentGIRD is best treated as an overhead-athlete risk / impairment measure, not a diagnostic test for a single pathology. Magee notes that internal rotation loss may reflect posterior / inferior capsular stiffness, soft-tissue adaptation, or humeral retrotorsion. Wilk’s work supports monitoring total rotational motion as well as internal rotation, because isolated GIRD can occur in asymptomatic throwers.