Figure 8c. (a) Normal anatomy of the inferior calcaneal nerve. Axial T1-weighted MR image (400/12) shows the lateral plantar nerve (white arrowhead), flexor retinaculum (black arrowheads), inferior calcaneal nerve (black arrow), and medial calcaneal nerve and vessels (white arrow). (b, c) Suspected neuropathy of the inferior calcaneal nerve. Coronal T1-weighted MR images (500/12) of the ankle were obtained in a healthy volunteer (b) and a 55-year-old patient with posterior tibial tendinopathy, flatfoot, and painful heel (c). Note the selective fatty atrophy (arrow in c) of the abductor digiti quinti muscle (ADQM) on the pathologic MR image compared with the normal image. AH = abductor hallucis muscle, FDB = flexor digitorum brevis muscle.