There are two main methods of abdominal percussion: 1. direct percussion. The doctor uses the middle three fingers of the right hand to tap on the examination area to determine whether there is a possible lesion through sound. 2. Indirect percussion. The doctor uses the index finger of the left hand on the affected area during the examination, the right hand is in a natural state, and the middle finger of the right hand taps on the second joint of the middle finger of the left hand to determine the condition of the examination site according to the frequency of sound and vibration. The sound and frequency of the vibration are used to determine the condition of the examined area. 2-3 taps are needed for each examined area to obtain a slightly clearer result. In clinical examinations, doctors more commonly use the indirect percussion method, which is also more reliable.