From Big Medical Encyclopedia

UNDULATION (Latin undulatus with a wavy outflow, wavy) — a phenomenon of distribution of a shockwave on a wall of a large cavity through the liquid which accumulated in this cavity. Diagnostic reception for definition of availability of liquid in perigastriums with pliable walls is based on this phenomenon (more often in an abdominal cavity). At. cause more vigorous, than at fluctuation (see Zyblepiye), effleurage on a wall of a cavity the bent fingers of one hand. At the same time the massive push of liquid is felt as a palm of other hand. Flabbiness and obesity of a front abdominal wall can provoke false undulation. In these cases it is necessary to cause At. in various provisions of a body of the patient.

At. it is noted at considerable ascites (see), large cysts (see the Cyst) and abscesses (see Abscess). This phenomenon is found at varicose expanded veins of the lower extremities (see the Varicosity): after korot

whom blow as fingers on a ball varicose of expanded veins of a shin other hand laid to a superficial vein of a hip feel a push of the running wave of a venous blood.