Physical Exam

Ankle-brachial Index

also known as Ankle-brachial pressure index; ankle-arm index

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Video coming September 2026

How to Perform

With the patient resting supine for about 10 minutes, use a blood-pressure cuff and a handheld Doppler probe to measure the systolic pressure at both brachial arteries and at both ankles (the dorsalis pedis and the posterior tibial). For each leg, divide the higher of its two ankle systolic pressures by the higher of the two brachial systolic pressures to obtain that leg's index.

How to Interpret

Medial Arterial Calcification

ABI >1.40

Rule in

Not helpful

Rule out

Not helpful

Evidence:Limited

Peripheral Artery Disease

ABI <0.90

Rule in

Somewhat helpful

Rule out

Somewhat helpful

Evidence:Limited

References

Xu D, Zou L, Xing Y, Hou L, Wei Y, Zhang J, Qiao Y, Hu D, Xu Y, Li J, Ma Y. Diagnostic value of ankle-brachial index in peripheral arterial disease: a meta-analysis. Can J Cardiol. 2013;29(4):492-498. doi:10.1016/j.cjca.2012.06.014. PMID: 22926041. Quality-assessed and tabulated by the Centre for Reviews and Dissemination (DARE summary NBK137929 on NCBI Bookshelf). Four included primary studies (569 patients, 922 limbs) comparing ABI <=0.90 against catheter angiography with >=50% stenosis as the reference standard for PAD; meta-analysis performed using Meta-DiSc software with DerSimonian-Laird random-effects pooling and summary ROC. AUC SROC = 0.87 (SE 0.02), Q* = 0.80 (SE 0.02). Updates the same group's prior structured review (Xu et al. Vasc Med 2010;15:361-369, PMID 20926495; DARE NBK79570) with additional studies. Supersedes the prior database citation of Herraiz-Adillo 2017 (Int J Clin Pract 71(9):e12994, PMID 28851093) for purposes of ABI-for-PAD diagnostic accuracy: Herraiz-Adillo 2017 is a methods-comparison meta-analysis of OSCILLOMETRIC ABI versus DOPPLER ABI agreement (with Doppler ABI as the reference standard within that study) -- a different question than ABI's accuracy for PAD against an imaging gold standard.
Ix JH, et al. Test characteristics of the ankle-brachial index and ankle-brachial difference for medial arterial calcification on X-ray in type 1 diabetes. J Vasc Surg. 2012;56(3):721-727. PMID: 22560306.
Winsor T. Influence of arterial disease on the systolic blood pressure gradients of the extremity. Am J Med Sci. 1950;220(2):117-126.