The axial (Harris) calcaneal X‑ray is an axial projection of the heel obtained with the foot dorsiflexed and the X‑ray beam angled through the calcaneus. It shows the calcaneal tuberosity, body, posterior facet and subtalar joint, plus medial and lateral walls. This view helps detect calcaneal fractures, assess displacement, heel width and subtalar joint congruity for treatment planning.

Initial X-ray for heel pain usually includes a weight-bearing lateral view of the calcaneus plus an axial (plantodorsal or Harris) calcaneal view to demonstrate the posterior and plantar calcaneus and heel spurs. A foot or ankle series (AP and oblique) may be added to assess fractures or alignment. For soft-tissue causes (plantar fasciitis), ultrasound or MRI are more sensitive.

Place the patient prone (or supine with knee flexed) with the foot dorsiflexed so the plantar surface is vertical. Put the cassette under the heel and center on the posterior calcaneus. Direct the central ray 40–45° cephalad along the long axis of the foot through the heel. Collimate to include the calcaneus and subtalar joint, immobilize the foot, and instruct the patient to hold still.

An axial projection is an X‑ray view taken with the central beam directed along the long axis of the body or body part. It images structures in the axial (transverse) plane, helping show spatial relationships and reduce overlapping anatomy. It’s commonly used for skull, spine, pelvis and certain joint exams to evaluate fractures, alignment and joint or spinal canal spaces.

The four standard ankle X‑ray views are anteroposterior (AP), mortise (AP with ~15–20° internal rotation to visualize the talocrural joint), lateral, and oblique. The AP shows tibia and fibula alignment, the mortise opens the ankle joint space, the lateral demonstrates anterior/posterior talar position, and the oblique helps reveal fibular and malleolar fractures.

The axis of the calcaneus is the longitudinal line through the heel bone, usually drawn from the most posterior point of the calcaneal tuberosity to the anterior process/center of the calcaneocuboid region. It represents calcaneal orientation and is used in radiographic and clinical assessment to measure hindfoot alignment, calcaneal pitch, and varus/valgus deformities.