Final answer:
The Roos test assesses for thoracic outlet syndrome by having the client perform specific arm movements for 3 minutes.
Step-by-step explanation:
The test that assesses for thoracic outlet syndrome by having the client abduct his or her arms 90 degrees externally rotated with elbows flexed 90 degrees and then have the client open and close his or her hands for 3 minutes is the Roos test.