Roller blade. Coloured X-ray of a foot seen in side view, wearing a roller blade. This four wheeled boot is used to skate" on hard surfaces. Bones and soft tissues of the lower leg and foot are visible. The ankle (centre left) links the leg to the foot. The lower leg bones are the tibia and fibula. The foot comprises many bones, including the calcaneus (heel bone), several tarsal bones, five metatarsals, culminating in the phalanges bones of the toes. The roller blade boot has three straps with buckles."