Fig. 2.

Illustration of the Scratch Collapse Test technique, which was modified after the initial technique, was published by Cheng et al. in 2008 [3]. a The initial resistance applied by the examiner to the dorsal surface of the patient’s forearms. b Scratching the patient’s arm at the cubital tunnel in the affected extremity. c Reapplying resistance to the dorsal forearms of the patient after the scratch provocation, with subsequent collapse of the affected extremity