The Diagnostic Accuracy of the Hyperextension–Internal Rotation (HERI) Test in Assessing Anterior Glenohumeral Instability

Background: To assess the diagnostic accuracy of the hyperextension–internal rotation (HERI) test to assess anterior glenohumeral instability. Methods: This study evaluated a total of 100 patients. The HERI test was performed on both the stable and unstable shoulder of each patient. The range of extension (°) was measured by a goniometer on both shoulders. Statistical analysis was performed to assess the diagnostic accuracy of the HERI test. Results: A total of 89% of patients showed evidence of an increased extension angle on the abnormal side by a mean of 84.19° compared with the normal contralateral side with a mean of 71.23°. The mean difference in extension angles between the normal and abnormal sides was 12.96°. In diagnosing anterior glenohumeral instability, the HERI test had a sensitivity of 88.8% (95% CI, 79.6–98%), a specificity of 87.3% (95% CI, 80.7–93.9%), and an accuracy of 88%. The positive predictive value was 87% (95% CI, 83.4–92.5%); the negative predictive value was 89% (95% CI, 84.6–93.3%); the positive likelihood ratio was 6.97 (95% CI, 3.4–10.4); the negative likelihood ratio was 0.13 (95% CI, 0.08–0.17); and the diagnostic odds ratio was 54.15 (95% CI, 47.2–61.0). Conclusions: The results of this diagnostic study indicate that the HERI test is a highly sensitive and specific test in assessing anterior glenohumeral instability without causing pain or producing a sense of instability.