Ballottement

Ballottement is a medical examination technique used to assess the size and consistency of an organ or mass within the body. It is particularly common in obstetric examinations to determine the position and mobility of the fetus. The term originates from the French word for "tossing" or "tumbled," aptly describing the motion involved.

In practice, ballottement involves gently tapping or pushing on a body part to cause a floating object within a fluid-filled cavity to rebound. For example, during pregnancy, a physician may place one hand on the patient's abdomen and gently tap with the other. If the fetus is freely mobile and surrounded by amniotic fluid, it will be displaced by the tap and then rebound back to its original position, creating a palpable sensation.

This technique can also be used to assess organs like the liver or spleen, or to detect masses in the abdomen. The examiner feels for the resistance or rebound of the organ or mass as it is displaced and returns. The degree of mobility and the sensation perceived by the examiner provide clues about the organ's size, consistency, and whether it is abnormally enlarged or displaced. It is a relatively simple and non-invasive diagnostic tool.