A physical therapist performs an examination on a patient diagnosed with thoracic outlet syndrome. During the examination, the therapist initiates a special test as shown in the image. Which of the following responses should the therapist consider a positive finding when performing this special test?
1. Inability to maintain the test position for three minutes
2. Subjective report of fatigue in the arms
3. Absence of a radial pulse after one minute
4. Failure of the hands to regain their normal color after 30 seconds