What does “Cuboid” Mean?
The cuboid is a small bone in the foot. It is located on the middle-outer edge closest to the small toe and attached to the calcaneus, AKA the heel bone. It is the only bone linking the straight, front half of the foot with the arched part of the foot and is therefore fundamental to maintaining stability. It also assists with supination and pronation (outward and inward rolling of the foot, respectively.)
What is Cuboid Syndrome?
Cuboid Syndrome is a common cause of lateral foot pain, especially in athletes. The cuboid bone partially dislocates due to an acute injury or repetitive movement of the foot that coaxes the bone out of place over time. It is commonly misdiagnosed, but is highly treatable. Cuboid Syndrome can also be referred to as peroneal cuboid syndrome, dropped cuboid, cuboid fault syndrome, subluxed cuboid, locked cuboid, or lateral plantar neuritis.
What causes Cuboid Syndrome?
There is no one definitive reason for Cuboid Syndrome, but speculative causes include overuse, inversion ankle sprains, and excessive pronation. Overuse causes repetitive strain to be put on the peroneus longus muscle in the leg. This muscle is involved in stability like the cuboid bone, and is similarly attached to the outer foot. Repeated stress causes soft tissue damage and friction, which can eventually lead to the dislocation that characterizes Cuboid Syndrome. During inversion ankle sprains, the cuboid bone is jerked in the opposite direction of the foot and heel and the soft tissue tears or becomes irritated. The damaged tissue cannot support the cuboid effectively so the bone sometimes dislocates. Pronated, or flat, feet often cause Cuboid Syndrome because they pull more frequently on the peroneus longus muscle.
Risk factors include…
- Ill-fitting footwear or orthotics
- Frequent, intensive exercise (especially running and dancing since they incorporate repetitive motions)
- Failing to do warm-up and recovery movements before exercising
- Exercising on uneven surfaces
- Having other foot/ankle injuries
What are the symptoms of Cuboid Syndrome?
Symptoms are similar to those of a sprained ligament, with radiating, local pain and inflammation. Potential symptoms may include, but are not limited to…
- Pain in the local area, especially during pushing off or side-to-side movement
- Inflammation (redness, swelling)
- Tenderness; difficulty putting weight on the foot
- Restricted movement
- Slight groove (or prominence) over the cuboid bone
How is Cuboid Syndrome diagnosed?
Cuboid Syndrome is often misdiagnosed, as many other types of foot disorders can cause lateral pain. In addition, physical abnormalities are most undetectable. Imaging is not often used because variations in the lateral part of human feet are common, therefore abnormalities would be hard to identify. Physicians mostly on patient history and physical examination, though imaging should be used as needed to rule out other pathology.
Patients may present with sudden or gradually increasing pain over the cuboid bone area, though the discomfort may also extend into the arch or along the fourth toe. Observed weakness during “pushing-off” motions is common, so gait evaluation and functional testing are important diagnostic tools. Physicians will also probably manipulate the foot in different planes to look for certain impairments and/or causes of pain. Range of motion may be decreased and pain may be triggered during flexion, inversion, and/or eversion.
How is Cuboid Syndrome treated?
Cuboid Syndrome responds well to conservative, non-invasive care. Physical therapy is the most common treatment method, including manipulation techniques specific to the cuboid bone and other foot strengthening exercises. Physicians may also recommend taping or cushioning the injured foot until the symptoms decrease or disappear. Ultimately, the goal is to alter any stresses that are affecting the bones and tissues around the cuboid.