Anatomy of the foot

The foot is a complex body part with multiple structures and functions. All structures in the foot must work together correctly and move properly to make walking and jumping possible. Stability during standing and movement is also extremely important. The foot therefore needs to be both stable and mobile.

Important structures in the foot are: bones, muscles, joint capsules, ligaments, nerves, and blood vessels. Altogether, the foot has thirty-three joints that provide mobility. Around each joint there is a joint capsule with ligaments.

Bones of the foot

The foot consists of:

• Toes (phalanges).
• Midfoot (metatarsus).
• Hindfoot (tarsus).

Toes
The toes are made up of fourteen small bones that together form five toes. Anatomically, the bones of the toes are very similar to the finger bones, but they are much shorter. Each toe consists of three bones, except for the big toe, which has two.

Midfoot
The midfoot contains five metatarsal bones (metatarsalia). Roman numerals I to V are used to indicate which metatarsal or toe is meant. The big toe is I and the little toe is V.

Hindfoot
The hindfoot consists of seven bones:

• Os talus.
• Os calcaneus.
• Os naviculare.
• Os cuboideum.
• Os cuneiforme mediale.
• Os cuneiforme intermedium.
• Os cuneiforme lateralis.

The two largest bones, the talus and the calcaneus, bear most of the body weight and act as the pivot point of the ankle. Together, these two bones form the subtalar joint.

Foot arches

The foot consists of three different foot arches. The bones of the foot, the ligaments, and the muscles determine the final shape of these arches. When the ligaments are taut (stretched), the foot acts as a stiff unit. When the ligaments relax, the foot moves more smoothly, which is important for shock absorption.

The foot has two arches that run along its length (see image). One arch lies on the inner side of the foot and the other on the outer side. These arches create the foot's hollow.

The third arch runs transversely across the foot at the level of the metatarsal bones just before the toes.

Function of the foot arches
The arches are composed of different bones of the foot. These bones together form various joints. The interplay of these joints creates a tightly coupled system for movements in the foot. This also means that when one joint has problems, another joint can compensate by moving more or less.

The structure of the foot determines the shape of the arches. Ligaments and muscles ultimately determine how the foot arches function. Many abnormalities of the foot arches can therefore be compensated for, except for abnormalities caused by structural issues. The best-known arch abnormalities are flat feet (pes planus) and high-arched feet (pes cavus).

Movements of the foot

The foot as a whole moves from the ankle joint. The only active movements that occur in the foot itself, without ankle movement, are flexion and extension of the toes.

In addition, a lot of movement occurs between the metatarsal bones and the bones of the hindfoot. These movements are important for absorbing movements or shocks, such as when walking on uneven ground. For example, when walking on the beach, movement occurs between the metatarsals to optimally maintain the shape of the foot arches. It is impossible to consciously and actively move metatarsal III separately from metatarsal IV.

The foot can be moved in three directions through the ankle. These movements almost always occur in combination.

Foot flexion and extension (standing on your toes and drawing your toes toward you)

• Plantarflexion (standing on the toes).
• Dorsiflexion (drawing the toes toward you).

Sideways movement of the foot

• Abduction (moving the foot outward).
• Adduction (moving the foot inward).

Tilting of the foot

• Supination (tilting the foot inward).
• Pronation (tilting the foot outward).

The best-known combination of movements that leads to an injury occurs during an ankle sprain (inversion injury). This involves simultaneous plantarflexion, adduction, and supination.

Foot complaints

Foot complaints can arise from incorrect movements, but also because structures become overloaded. A good overview of foot complaints that cause pain in the foot can be found on the page pain in the foot. Do you need help getting rid of your foot complaints? Then make an appointment with a physical therapist near you.