Immobilizing performances, comfort, and user-friendliness of the shoulder abduction-external rotation braces

Background. Shoulder external rotation braces used for patients with a first-time shoulder dislocation are designed with a variety of arm positions in abduction as well as external rotation. However, few studies have focused on their immobilizing performance, comfort, or user-friendliness. Especially, there have been no robust data of shoulder abduction-external rotation (A-ER) braces in comparison to those of external rotation (ER) braces. Methods. Four types of commercially available shoulder braces (two ER and two A-ER braces) were tested in 30 healthy participants. The angles of external rotation and abduction were measured for each brace at initial application, after simulated daily activities, and after reapplication. Then, subjects were asked to assess the discomfort of bracing and difficulty of reapplication using a visual analogue scale. Data were compared between the two ER braces and two A-ER braces as well as among the four braces. Results. For both external rotation angle and subjective assessment, there were no significant differences between the ER and A-ER braces. Among the four braces, the measurement of arm position demonstrated no significant differences, except the external rotation angles between the two ER braces. The A-ER braces were assessed to be significantly less comfortable than the ER braces in the subjective assessment. Conclusions. Immobilization using the A-ER braces could maintain the arm position in abduction-external rotation with comparable user-friendliness, although they tended to be less comfortable during daily activities compared to the ER braces.