Arterial pulse (amplitude, large)

In this wave form the upstroke is abrupt and steeper than normal. The peak of the wave form is reached earlier than normal and there is a rapid downstroke. The amplitude of the wave form is abnormally wide.

• with the patient reclining, the examiner raises the patient's arm vertically upwards. The examiner grasps the muscular part of the patient's forearm. A waterhammer pulse is felt as a tapping impulse which is transmitted through the bulk of the muscles
  
  
• a waterhammer was a Victorian toy in which a tube was half filled with fluid, the remainder being a vacuum. The child would invert and reinvert the tube; each time the impact of the fluid at each end would sound like a hammer blow

Reference:

Pabba K et al. Water Hammer Pulse. In StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan.