Video: Cuboid bone

Hello everyone! This is Nicole from Kenhub, and in this tutorial, we will be looking at the cuboid bone.

So we’re back with our view of the lateral aspect of the foot and, in this image, we can see our tibia medially here and our fibula laterally here. So, the cuboid bone highlighted in green here is a short bone of the foot situated in the distal row of the tarsal bones and is also the most lateral tarsal bone. It lies between the calcaneus proximally and the fourth and fifth metatarsals distally, while the lateral cuneiform and the navicular bones are situated medially.

So as we can tell from the name, the cuboid bone has a cubical or square-like shape. It's also got a rough dorsal surface for the attachment of ligaments. The cuboid's distal plantar surface contains a deep groove called the peroneal sulcus which lodges the tendon of the peroneus longus muscle. The cuboid functions as a pulley for the tendon of the peroneus longus muscle which if we recall acts to evert – so turn the foot away from the median plane – and plantarflex the ankle which is the action decreasing the angle between the sole of the foot and the back of the leg. For example, pointing the toe like you're a ballet dancer.

Posterior to the peroneal sulcus lies the tuberosity of cuboid which provides an attachment site for the long plantar ligament and the long plantar ligament connects the calcaneus to the cuboid bone.

So as we can see from this image, the cuboid bone forms articulations with four bones of the foot – the calcaneus posteriorly, the lateral cuneiform medially, the fourth metatarsal and the fifth metatarsal both distally. Additionally, cuboid articulation with the navicular has been found to occur approximately twenty five percent of the time. So, looking at all of the many articulations formed with the cuboid, we can see why it's considered the main bone of the midfoot.

The cuboid receives arterial blood supply from the deep branches of the medial plantar artery and the lateral plantar artery as seen from a plantar view, and both of these are branches of the posterior tibial artery.

Venous drainage is provided by the deep venous arch while innervation of the cuboid is provided by the lateral plantar, sural and deep fibular nerves.