Anatomy
The tarsal comprises all structures that are located between the fibula, the shinbone and the toes. This includes 7 tarsal bones, which can be divided into two rows, but also several joints, as well as the entire ligament and muscle apparatus in this region. The tarsal bones can be divided into a row of bones located closer to the trunk, the so-called “proximal” row, and a “distal” row of bones located close to the toes.
The proximal row consists of the talus and the calcaneus. The distal row contains several small bones. These include the scaphoid bone “Os naviculare”, the cuboid bone “Os cuboideum” and three sphenoid bones “Ossa cuneiforme”, which are further subdivided into a middle bone, an outer bone and a bone located in between.
The heel bone is probably the most prominent, since it forms the classic heel, is the largest bone of the foot and has to bear a large part of the total body weight. All tarsal bones are closely connected by tight ligaments, which stabilize especially the two ankle joints and enable the foot to stand upright and securely. The projection that the heel bone forms is also known as the “tuber calcanei”.
Among other things, it has a function as the starting point of the Achilles tendon, which is why this region is known as the Achilles heel. The Achilles tendon itself is the attachment of a multipart muscle that originates from the thigh and forms the majority of the muscular calf. Its function is to stretch the foot as a whole.
The two ankle joints are particularly important for the movements of the foot. Due to the high weight load and stability requirements, the joints are very tightly secured by ligaments, which accordingly restricts mobility compared to the hand. In the upper ankle joint, the ankle bone “talus” is completely surrounded from above and from left and right by the two lower leg bones, the fibula on the outside and the tibia on the inside.
This can be felt and is also visible from outside in the form of the two ankles. As a result, the main movement in this joint consists only of stretching or pulling the foot (“extension” and “flexion”). From bone to bone, different ligaments are stretched inside and outside, which have a lateral stabilization function.
These ligaments are referred to collectively as the medial collateral ligament and the lateral ligament. The lower ankle joint is further divided into a lower anterior and a posterior lower ankle joint. In the posterior lower ankle joint, the heel bone and the ankle bone are in articulated connection with each other, whereas in the anterior lower ankle joint, the proximal tarsal bones form a joint with the scaphoid bone.
Since this joint extends over several bones and is anatomically divided into two individual joint capsules, it must also be secured and stabilized by a number of tight ligaments. The lower ankle joint allows “supination and pronation movements” to be performed to a limited extent. This means that the middle and outer edges of the foot can be lifted.