Anatomy
The heel bone (lat. Calcaneus) is the largest and dominant foot bone and has a slightly cuboid shape. As part of the rear foot, a part of the heel bone stands directly on the ground and serves for stability.
The heel bone is divided into different parts which fulfill different functions and tasks. More about the heel can be found here: Achilles heelThe rear prominent part of the heel bone is called tuber calcanei and is visible and palpable as the heel of the foot. This is where the Achilles tendon, the twin calf muscle (Musculus gastrocnemius) and the sole muscle (Musculus soleus) come into play.
On its underside, a stabilizing band runs between the calcaneus and the cuboid bone (Ligamentum calcaneocuboideum). There are also two cusps on the underside, the lateral tuberosity of the calcaneus and the medial tuberosity of the calcaneus. These serve as the origin for the musculus abductor hallucis, the musculus flexor digitorum brevis and the musculus abductor digiti minimi.
The tendon plate in the area of the sole of the foot, Aponeurosis plantaris, also has its origin in the tuber calcanei. Towards the front, the heel bone forms a joint with the cuboid bone (Os cuboideum). There are bony protrusions on both the inside and outside of the heel bone, which serve to protect and guide muscles.
On the inner side of the foot is the sulcus tendinis musculi flexoris hallucis longus, which contains the long flexor muscle of the big toe and prevents the heel bone from buckling inwards. This is covered by a bony projection, the tali sustentaculum. On the outside of the foot is the sulcus tendinis musculi peronei longi.
This muscle serves to tension the transverse arch. In addition, various nerves and blood vessels run through these archways. On the upper side of the calcaneus there are three joint surfaces, the Facies articularis talaris anterior, Facies articularis talaris media and Facies articularis talaris posterior.
The calcaneal sulcus runs between the latter two articular surfaces, which together with the talar sulcus of the ankle bone forms a tunnel known as the tarsi canal. The anterior (anterior) and middle (medial) articular surfaces are parts of the anterior ankle joint. The posterior articular surface is part of the posterior ankle joint. The entire calcaneus and especially the posterior prominent part is the decisive pressure point for upright standing and walking.
