The use of palpation to simultaneously evaluate both radial pulses in an attempt to determine any delay and/or discrepancy.
With your patient lying inclined at roughly forty-five degrees, the practitioner supinates the patient’s wrist and locates the radial artery, just proximal to the carpal tunnel on the lateral side of the wrist, medial to the radius. This procedure is repeated on both sides.
A radio-radial delay may be the result of a cervical rib pressing on the subclavian artery of one arm, delaying the radial pulse on that side. Other possible causes include: emboli, dissecting thoracic aorta, aortic aneurysm and occlusion.
A radio-radial delay warrants referral for further specialised investigations.