Which ABI value indicates probable claudication?

• A. <0.80 probable claudication
• B. <0.95 abnormal
• C. >0.95 normal
• D. <0.30 ischemic rest pain

Answer: (A)

The main idea is that the Ankle-Brachial Index measures leg perfusion by comparing ankle and arm pressures. Normal perfusion yields an ABI around 1.0; as peripheral arterial disease progresses, the ABI falls. Claudication occurs when blood flow is insufficient to meet the muscles’ needs during walking, so a lower ABI reflects this perfusion deficit. An ABI below 0.80 is the threshold most strongly associated with claudication because the arterial obstruction is typically significant enough to produce symptoms during exertion. Values above 0.95 are considered normal or near-normal, and very low values (for example, below 0.30) suggest rest pain and more severe ischemia. Therefore, an ABI value below 0.80 indicates probable claudication.