Figure 1.

The scratch collapse test. The figure illustrates the scratch collapse test. The patient faces the examiner with arms adducted, elbows flexed, and forearms parallel to one another with wrists at neutral. Step A: The patient resists bilateral internal rotation forces applied by the examiner. Step B: Next, the examiner “scratches” or swipes with fingertips over the course of the nerve (ulnar nerve at elbow illustrated). Step C: Step A is immediately repeated. Brief unilateral reduction in the patient’s resistance to internal rotation is considered a positive scratch collapse test. Reprinted with permission [6].