in this video we are going to show you the Roos or elevated arm stress test for thoracic outlet syndrome. get our very own assessment ebook and mobile app links are in the video description hi and welcome to Physiotutors. Thoracic outlet syndrome is defined as a neurovascular symptom complex associated with compression of the brachial bundle which includes the brachial plexus and/or subclavian vessels this compression may be caused by several anatomical structures in one or more of the following three compartments: the inter scalene triangle, the costoclavicular space, or retropectoralis minor space. The Roos test is believed to stress all of the three intervals since this position places the arterial, venous and nervous system in tension. According to Gillard et al. in the year 2001 the Roos test had a sensitivity of 84% and a specificity of 30%. Regarding the rather low accuracy values and due to the fact that the study did not make use of MRI as the gold standard, the clinical value of this test is rather weak. To perform the test the patient sits with the head in the neutral position, the arms Abducted and externally rotated to 90 degrees and the elbows flexed to 90 degrees. The patient is then requested to flex and extend the fingers for up to three minutes. The examiner watches for any dropping of the extremity during this time which could indicate fatigue or arterial compromise. The therapist should also observe the color of the distal extremity comparing left with right and monitors symptom onset. This test is positive when the patient is unable to maintain elevation for a 3 minute period or when symptoms are induced. Alright, this was the video on the Roos test which is believed to be the most sensitive test for TOS. If you want to learn how to conduct other tests for TOS, click on the playlist to my left. As always thanks a lot for watching and please don't forget to hit the like and subscribe button if you like the video. All of our videos including literature and evidence statements can be found in our very own assessment ebook, mobile app, or online course. This was Kai for Physiotutors, I'll see you in another video bye!