RESUMO
OBJECTIVE: To determine the effectiveness of glenohumeral-joint stability braces in limiting active and passive shoulder abduction and external rotation in collegiate football players. DESIGN AND SETTING: A 2-factor, repeated-measures design was used. The independent variables were brace condition (Denison and Duke Wyre harness, Sawa shoulder brace) and force application (active, passive). The dependent variables were shoulder abduction (45 degrees braced limit) and external-rotation angular displacements. SUBJECTS: Fifteen National Collegiate Athletic Association Division I male college football players (age = 19.9 +/- 1.37 years, height = 183.2 +/- 7.85 cm, mass = 89.9 +/- 14.79 kg) participated in the study. MEASUREMENTS: We used the PEAK Motus motion analysis system to measure angular displacements. RESULTS: Neither brace maintained the arm position at the 45 degrees braced limit during active or passive shoulder abduction (motion ranged from 56.8 degrees to 73.0 degrees ). Although we did not use a priori external-rotation limits in this study, motion ranged from 71.6 degrees to 93.9 degrees with the braces. A repeated-measures multivariate analysis of variance indicated no significant interaction effect (P =.41), but main effects were significant for brace condition and force application (P <.001). Reported differences are statistically significant. For abduction, the Denison and Duke Wyre harness resulted in 12.3 degrees (21%) greater angular displacement than the Sawa shoulder brace, and passive abduction resulted in 3.9 degrees (6%) more angular displacement than active abduction. For external rotation, the Denison and Duke Wyre harness resulted in 6.7 degrees (9%) more angular displacement than the Sawa shoulder brace, and passive external rotation resulted in 15.6 degrees (21%) more angular displacement than active external rotation. CONCLUSIONS: Preset, braced abduction motion limits were not realized during active and passive physiologic loading of the glenohumeral joint. However, protection against the vulnerable position of 90 degrees of abduction and external rotation was attained at a preset braced limit of 45 degrees of abduction (the exception was the Denison and Duke Wyre harness during passive external rotation). The Sawa shoulder brace was most effective for this purpose.