What is the medical term for involuntary muscle guarding of the abdomen?

• A. Rebound tenderness
• B. Rigidity
• C. Voluntary guarding
• D. Tachycardia

Answer: (B)

The correct term for involuntary muscle guarding of the abdomen is "rigidity." This phenomenon occurs as a protective mechanism in response to inflammation, pain, or irritation in the abdominal cavity. When the abdominal muscles involuntarily contract and become stiff, it indicates that there may be an underlying pathology such as peritoneal irritation, which can be seen in conditions like appendicitis or peritonitis.

In the context of a clinical examination, rigidity is often assessed during a physical exam when the clinician palpates the abdomen. If the muscles remain tense regardless of the examiner's attempt to relax them, this suggests a serious condition that may require further investigation or intervention.

Other terms mentioned such as rebound tenderness refer to a different phenomenon, where pain is elicited upon the release of pressure from the abdomen, indicating peritoneal irritation as well. Voluntary guarding is when a patient consciously tightens their abdominal muscles in response to pain, whereas tachycardia refers to an increased heart rate and is not directly related to abdominal muscle rigidity.