The toes (lat. : digitus pedis) are the terminal limbs of the human foot. Normally a human being has five toes on each foot, which are systematically numbered from the inside out in the anatomy with Roman numbers from one to five.
The big toe is therefore called digitus pedis I or also called hallux, the second toe is called digitus pedis II, the third toe is called digitus pedis III, the fourth toe is called digitus pedis IV and the little toe is called digitus pedis V or also digitus minimus. Just like the fingers on your hand, each toe has a nail. The toes play an important role for the mobility of the foot as well as for a secure stand and gait.
Bones and joints
At each foot the human being has a total of 14 phalanges. The big toes (digitus pedis I or hallux) are made up of two bones each, the remaining toes (digitus pedis II to V) are made up of three bones each. These bones, which divide the toes into two or three limbs respectively, are called the base limb (lat.
: phalanx proximalis), middle limb (lat. : phalanx media) and end limb (lat. : phalanx distalis) (since the big toe is only formed from two bones, there is only one base limb and one end limb, no middle limb).
The base, middle and end phalanx of a toe again consist of three areas, which in anatomy are called base, body and head. The limbs or bones of a toe are connected by joints. The head of one limb forms a joint with the base of the following limb.
The joint between the metatarsal bones and the base is called the metatarsophalangeal joint. The joint between the metatarsals and the metatarsophalangeal joint is called the metatarsophalangeal joint or proximal interphalangeal joint (PIP). The joint between the metatarsals and the distal joint is called the distal interphalangeal joint (DIP). The joints of the toes are surrounded by connective tissue joint capsules and thus secured.
Muscles and movements
The joints of the toes are where numerous muscles start, originating either from the bones of the lower leg or from the bones of the foot. Through a coordinated interaction of these muscles it is possible to move the toes in many different directions. Firstly, the toes can be bent towards the ground, which is called flexion.
On the other hand they can be stretched towards the ceiling, which is called extension. Furthermore it is possible to spread the toes apart. The spreading of the toes is called abduction.
If the spread toes are brought back to their original position, this is called adduction. The bending of the toes (flexion) is carried out by the toe bending muscles. In anatomy, a distinction is made between the long toe flexors, which originate from the bones of the lower leg and from there move towards the toes, and the short toe flexors, which originate from the sole of the foot and thus have a shorter course to the toes.
Important representatives of the long toe flexors are the muscle flexor hallucis longus, which is responsible, among other things, for a bending movement of the joints of the big toe (digitus pedis I or hallux) and the muscle flexor digitorum longus, which performs the bending of the other toes (digitus pedis II to V). The short toe flexors are the abductor hallucis muscle, the flexor digitorum brevis muscle, the adductor hallucis muscle, which supports the flexion of the big toe (digitus pedis I or hallux), and the flexor digitorum brevis muscle, which contributes to the flexion of the other toes (digitus pedis II to V). The abductor digiti minimi muscle also supports the flexion of the little toe (digitus pedis V or digitus minimus).
Stretching of the toes (extension) is ensured by the toe extensor muscles. Here too, the anatomy of long toe extensors, which originate from the lower leg bones, can be distinguished from short toe extensors, which originate from the bones of the foot. Long toe extenders include the musculus extensor hallucis longus and the musculus extensor digitorum longus.
The musculus extensor hallucis longus is used to extend the big toe (digitus pedis I or hallux) towards the ceiling, the musculus extensor digitorum longus is used to extend the other toes (digitus pedis II to V). The short toe extensors, the musculus extensor hallucis brevis and the musculus extensor digitorum support the extension of the toes towards the ceiling. Spreading of the toes (abduction) is made possible by the Musculi interossei dorsales. Closure of the spread toes is ensured by the lumbrical and interosseous plantar muscles.