The healer had seen and treated his share of people suffering from post traumatic stress disorder, and it was evident, that this kid is being affected by a severely upsetting event in his probably recent past. Bucky obviously had never heard of phantom limb pain, and he seemed bewildered even trying to explain his situation.
Hannibal nodded slightly, even though the boy's eyes were trained at the table. “You are experiencing pain where it shouldn't be.” He paused for a moment, while observing the boy, only because he guessed, that Bucky was painfully expecting not to be taken seriously. But the healer soon relieved him from his dilemma: “Do not worry. This is quite common for amputees, Mr. Barnes. How long has it been since you've lost your arm?”