Lateral foot pain is pain that runs along the outer side of the foot and ankle. It can occur before, during, or after activities such as walking and running. Lateral foot pain can make it difficult for people to move around or even stand.
Lateral foot pain can cause a variety of symptoms, most of which depend on which part of the foot is affected.
The most common symptoms include:
- pain on the outer side of the ankle
- instability of the foot
- difficulty walking
- susceptibility to ankle sprains
- difficulty in standing on the foot
Lateral foot pain can have many causes. Most of them arise from conditions that were left untreated. These could include:
- ankle joint inflammation and scar tissue
- the presence of very fine cracks in the foot bones and in the ankle
- tendon inflammation
- stretched, torn, or pinched nerves (especially those passing through the ankle)
The following conditions lead to lateral foot pain:
An ankle sprain is a ligament injury in the foot, without dislocation or a fracture. This is one of the main causes of lateral foot pain, with 85 percent of ankle sprains leading to lateral foot pain.
Cuboid syndrome is a partial dislocation of one of the lateral foot bones known as the cuboid bone. This injury may occur due to excessive tension or too much weight on the bone.
This syndrome usually occurs when a person does too much sport and physical activity without allowing any recovery time between exercise sessions. Sometimes, wearing tight shoes can also cause cuboid syndrome.
Cuboid syndrome is an uncommon cause of lateral foot pain that frequently goes undiagnosed. It can cause long-term symptoms, such as pain, weakness, and tenderness.
Bunions are a bone defect that makes the big toe of the foot rotate inwards and point to the other toes. As a consequence, people put most of their body weight on the lateral side of the foot when walking or standing, which causes pain.
Bunions may be caused by genetic factors or poor footwear that squashes the toes. In severe cases, surgery may be necessary to remove the bunion and realign the toes.
Peroneal tendonitis occurs as a result of repetitive tension of the peroneal tendons. These two tendons extend from the back of the calf, over the outer edge of the outer ankle and attach at different points on the lateral side of the foot.
This condition causes the peroneal tendons to swell or become inflamed, resulting in pain on the lateral side of the foot and the heel.
A person who runs excessively or places their foot abnormally may develop peroneal tendonitis. It may also occur after an ankle sprain.
Stress fractures are small breaks in one of the outer foot bones (called metatarsals), due to repetitive sports and physical exercise. Symptoms of this injury may be mild initially but gradually worsen.
Calluses and corns
Corns and calluses develop on the lateral side of the foot. They often develop as a result of the body producing multiple skin layers to protect the foot from repetitive stress and friction. Although calluses are usually painless, corns can penetrate deeper into the skin and be painful.
Arthritis is a disease that causes lateral foot pain when it affects the foot joint. Rheumatoid arthritis is the most common type of arthritis.
Tarsal coalition is a congenital condition, meaning that it is present at birth. Tarsal coalition occurs when the tarsal bones near the back of the foot do not connect properly. This unusual connection between the two bones often leads to stiffness and pain in the foot.
Tarsal coalition is a rare condition. According to the American Academy of Orthopedic Surgeons, about 1 in every 100 people have the condition.
Lateral foot pain may persist for some time and require treatment.
A person can relieve mild lateral foot pain fairly quickly by following the RICE method:
- Rest the foot
- Ice the foot for regular periods of 20 minutes each
- Compress the foot with an elastic bandage
- Elevate the foot above heart level
For mild cases of lateral foot pain, a person can rest and use over-the-counter medications to reduce swelling and relieve the pain. In more severe cases, a doctor may prescribe anti-inflammatory medications.
If medications do not work, physical therapy may be necessary. This type of therapy aims to relax the muscles, improve blood flow, and help the foot heal properly. The doctor may also recommend stabilizers to support and protect the ankle.
In case of injury to the softer tissues of the ankle and foot, a doctor may recommend steroids.
In case of injury to the bone, the doctor may advise immobilization of the foot.
Other treatments that may be used alongside medications include electric stimulation, laser or light therapy, or surgery in rare and severe cases.
To diagnose lateral foot pain, the doctor will probably perform a physical examination of the foot. The doctor will check the mobility and stability of the foot. The doctor will also look for swollen areas, foot deformities or injuries, and symptoms of pain.
The doctor may also recommend diagnostic exams to help determine the cause of foot pain. These may include an X-ray or a magnetic resonance imaging (MRI) scan.
Most cases of lateral foot pain result from mild pre-existing conditions, which can worsen over time if not treated. In the most severe cases, people can experience pain when they move their foot or stand upright.
In cases where a pinched nerve causes lateral foot pain, a person may lose some or all of the sensitivity in their foot.
A person can prevent lateral foot pain with basic precautionary measures, such as rest. Wearing shoes that have a foot arch support can also help when walking, running, jogging, or cycling.