A 39-year-old man presents with severe right index-finger pain and swelling 48 hours after a thorn-prick injury.
Vitals: Temp 38.2 °C, HR 104 bpm, BP 124/72 mmHg.
Exam: The digit is swollen and tender along the ventral surface.
Which of the following is NOT a classical Kanavel sign of acute flexor tenosynovitis?