Radial nerve arm, and later in the anterior compartment of the arm, and continues in the posterior compartment of the forearm. The radial nerve originates from the posterior cord of the brachial plexus with root values of C5 to C8 and T1. From the brachial plexus, it travels behind the third part of the axillary artery (part of the axillary artery distal to the pectoralis minor). In the arm, it runs behind the brachial artery and then enters the lower triangular space to reach the radial sulcus of back of the humerus. It travel downwards together with profunda brachii atery, between the
Ankle–brachial pressure index ABPI is the ratio of the highest ankle to brachial artery pressure. An ABPI between and including 0.9 and 1.2 considered normal (free from significant PAD), while a lesser than 0.9 indicates arterial disease. An ABPI value of 1.3 or greater is also considered abnormal, and suggests calcification of the walls of the arteries and incompressible vessels, reflecting severe peripheral vascular disease. Provided that there are no other significant conditions affecting the arteries of the leg, the following ABPI ratios can be used to predict the severity of PAD as well as assess the nature and best management of various