(a)
(b)
(c)
(d)

Figure 3: (a) The entry point through SCM midline lateral for superficial cervical plexus block (b). SCM, sternocleidomastoid muscle, CA, carotid artery, ASM, anterior scalene muscle, and MSM, middle scalene muscle. (c) Needle and SCM (d) local anesthetic distribution and SCM.