The cuboid bone is one of the seven tarsal bones of the foot, forming part of the skeletal structure that facilitates movement and supports the body’s weight. This cube-shaped bone is a component of the midfoot, located in a position that gives it a significant role in foot mechanics. It acts as a central piece in the foot’s lateral column, providing stability and flexibility during standing and walking.
Identifying the Cuboid’s Location
The cuboid bone is situated on the lateral, or outer, side of the foot, positioned within the midfoot region. It is the most lateral bone in the distal row of the tarsus, the group of bones between the ankle and the metatarsals.
The cuboid bone forms connections with five other bones. Proximally, toward the ankle, it links with the calcaneus (the heel bone). Distally, toward the toes, it articulates with the fourth and fifth metatarsal bones.
Moving inward, the cuboid connects medially with the navicular bone and the lateral cuneiform bone. This set of joints helps stabilize the lateral column of the foot, which is essential for adapting to uneven surfaces.
The Cuboid’s Role in Foot Mechanics
The cuboid bone plays a part in maintaining the structural integrity of the foot, particularly the lateral longitudinal arch. The cuboid acts as the central support element for this arch, which is relatively low compared to the inner arch. This positioning allows the bone to redistribute a portion of the body’s weight to the heel and the outer metatarsals.
A groove known as the peroneal sulcus is located on its inferior (bottom) surface. This specialized channel accommodates the tendon of the fibularis longus muscle (peroneus longus). As this tendon passes through the groove, the cuboid acts as a pulley system, which is important for moving the foot outward (eversion) and supporting the transverse arch.
This pulley action is important during the push-off phase of walking and running. The bone’s stability and movement contribute to the mobility of the lateral foot column, enabling the foot to function efficiently.
Common Issues and Injuries
The most common issue is Cuboid Syndrome, which involves a subtle misalignment or partial dislocation (subluxation) from neighboring bones, most often the calcaneus. Pain is typically felt on the outer side of the foot, near the midfoot area or the base of the fourth and fifth toes.
Cuboid Syndrome frequently occurs following an ankle sprain, particularly an inversion sprain where the foot twists inward. Repetitive stress from activities like running or ballet, or wearing unsupportive footwear, can also contribute to the misalignment. The resulting pain can make walking difficult and may be mistaken for conditions like a stress fracture.
Fractures of the cuboid bone are rare because it is protected within the midfoot structure. When they occur, they are typically the result of severe trauma, such as a crush injury or a high-energy event causing a Lisfranc injury. Fracture symptoms, including swelling and tenderness, can closely resemble those of Cuboid Syndrome.