Despite considerable advances in the understanding of glenohumeral (GH) biomechanics and glenoid labral pathologies, arthroscopy remains the only definitive means of SLAP lesion diagnosis. Unfortunately, natural GH anatomic variants limit the reliability of radiographic implications. Accurate clinical diagnostic techniques would be advantageous due to the invasiveness, patient risk, and financial cost associated with arthroscopy. More than 20 provocative tests designed to elicit labral symptoms as a diagnostic sign have shown promising accuracy by their respective original authors, but follow-up studies generally fail to reproduce those findings. The purpose of this study was to compare the behavior of GH joint stabilizing muscles in seven promising provocative tests. Electromyography (EMG) was used to characterize the activation of GH joint stabilizing muscles, with particular interest in the long head biceps brachii (LHBB) behavior, as activation of the LHBB and subsequent tension in the biceps tendon should illicit labral symptoms in SLAP lesion patients .