Cuboid Syndrome is a common cause of lateral foot pain i.e. pain on the outer side of the foot. Whilst fairly simple to treat, it is often misdiagnosed so symptoms can last for a long time. It particularly affects athletes such as ballet dancers and runners.
The condition develops when the cuboid bone (one of the small bones in the foot) subluxes i.e. partially dislocates. This may happen suddenly due to an injury such as an ankle sprain, or develop gradually overtime from repetitive tension through the bone and surrounding structures.
Here, we will look at the common causes of cuboid syndrome, how it presents, diagnosis and the best treatment options.
The cuboid is one of the small bones
on the outer side of the midfoot. It attaches to the heel bone
(calcaneus) via a number of strong ligaments and a joint capsule forming
the calcaneocuboid joint.
Trauma to the foot, be it a sudden injury or gradually repetitive forces may damage the supporting soft tissues causing the cuboid bone to move out of its usual position. It can then act like a block, limiting the movement of the surrounding bones in the foot.
Other terms commonly used are cuboid subluxation, blocked cuboid, dropped cuboid, lateral plantar neuritis and cuboid fault syndrome.
There are three main causes of Cuboid Syndrome:
1) Injury: The most common injury that causes cuboid subluxation is an inversion sprain of the ankle. This is when the foot and heel bone are forced inwards while the cuboid is forced outwards.
This inwards twisting damages the soft tissues which support the bone in place causing it to partially dislocate. In this instance, pain usually comes on suddenly.
2) Repetitive Strain: The peroneus longus muscle runs down the outer side of the lower leg attaching on to the outer side of the foot. Tension placed through this muscle from repetitive activities such as ballet (pointing), jumping and running may cause excessive traction on the bone causing it to sublux.
In this case, symptoms come on gradually over time and often fluctuate.
3) Altered Foot Biomechanics: Studies have shown that a majority of people suffering from cuboid subluxation have over-pronated feet i.e. flat feet.
Cuboid Syndrome classically presents with pain down the outside of the foot which can refer across the foot and to the ankle and toes. Pain is usually worse when weight-bearing particularly first thing in the morning, on uneven ground, quickly changing direction, jumping or hopping and symptoms tend to ease with rest. Walking may be difficult and people with cuboid subluxation often walk with a limp in an attempt to keep their weight of the outer foot.
The bone is usually tender to touch and the area may be slightly red and swollen. The foot may also feel weak, especially during the push-off phase of walking, running and jumping.
Diagnosing a subluxed cuboid can be difficult and it is often misdiagnosed. Imaging such as x-rays, MRIs and CT scans often fail to show a cuboid subluxation but they can be useful for ruling out other causes of pain.
There is no conclusive test for Cuboid Syndrome but your doctor will usually assess to see if there is pain and stiffness on palpation of the bone (when they press firmly on the cuboid through the sole of your foot). They may also move your foot inwards and outwards to see if that elicits pain or get you to try and hop.
Some health professionals may use the midtarsal adduction test or midtarsal supination test to assess for the condition.
Cuboid Syndrome often goes undiagnosed with ankle sprains. If symptoms continue more than three months following an inversion sprain, cuboid subluxation should be considered.
There are a number of different treatment options for Cuboid Syndrome.
Exercises are a vital part of treatment when recovering from cuboid syndrome. Pain-free strengthening and movement exercises should be performed daily to prevent the foot from getting weak and stiff. Balance exercises should also be introduced once symptoms have settled. If balance work is ignored, you are at increased risk of further foot and ankle injuries such as ankle sprains in the future.
Exercises should be started as soon as possible, gradually progressed as symptoms allow and continued until full function of the foot is restored.
The quicker treatment commences following a cuboid subluxation, the quicker full function will be restored. Chronic (long-term) cases, will take longer to heal.
Taping of the foot and ankle is often used to support and stabilize the bones in the foot and hold the cuboid in place while the surrounding soft tissues heal. Taping should allow you to walk without pain.
The most successful treatment for a subluxed cuboid is to have the bone relocated back into its proper position. A health professional such as a doctor, physical therapist or podiatrist will perform a manipulation, which is a high velocity (quick) small amplitude thrust to the bone to relocate it. This should only ever be carried out by a trained professional. Symptoms will usually settle immediately. Manipulations are not suitable if you suffer from gout, bone disease, fracture, rheumatoid arthritis or nerve or vascular problems.
Following successful manipulation, other treatments will help to keep the bone in the correct position and to treat any lingering symptoms.
Ice therapy can help to reduce pain and inflammation from cuboid syndrome. Place an ice pack or bag of frozen veg wrapped in a tea towel over the outside of the foot for ten minutes at a time.
To find out more visit the Ice Therapy section including how to safely and effectively use ice.
It is important to rest from aggravating activities while the foot heals. This may require the use of crutches for a short period of time to keep weight off the injured foot.
If over-pronation of your foot (i.e. flat feet) is thought to have been a contributing factor to developing cuboid syndrome, you should be given orthotic insoles to wear in your shoes to correct your foot position to relieve tension on the peroneus longus tendon and support the foot bones and arches.
You may also be given a small foam wedge to wear in your shoe which also helps to support the bone in the correct position.
There are a number of other causes of pain on the outside of the foot other than Cuboid Syndrome. If this is not sounding like your problem, visit the side foot pain or foot pain diagnosis sections for helping working out what is causing your pain.
1) 80% of people with cuboid subluxation have over-pronated feet
2) Cuboid Syndrome accounts for 4% of foot injuries in athletes but 17% of foot injuries in ballet dancers
3) 6.7% of ankle inversion sprain sufferers also have a subluxed cuboid
4) The cuboid bone rotates approximately 25 degrees when inverting and everting the foot (turning it inwards and outwards)
Source: Sports Health Journal