Foot pain on the outside, or lateral side, is common and can disrupt daily activities. This discomfort can arise from sudden injuries or gradual wear. Understanding the foot’s structures and potential causes helps address this issue.
Understanding Your Lateral Foot
The human foot is a complex structure, and its lateral side contains several bones, ligaments, and tendons that work together to provide stability and allow movement.
The fifth metatarsal is a long bone on the outer edge of the foot, connecting the little toe to the ankle. It supports the foot’s arch and facilitates movement, with a base serving as an attachment point for muscles and ligaments.
The cuboid bone, a cube-shaped bone, is on the outer midfoot, in front of the heel. It connects with five other foot bones, stabilizing the outer edge, distributing weight, and aiding toe movement.
Ligaments are strong tissues connecting bones, providing joint stability. Lateral ankle ligaments, including the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), prevent excessive inward foot rolling. The ATFL is often the most commonly injured ligament in an ankle sprain.
Tendons connect muscles to bones. The two peroneal tendons, peroneus longus and peroneus brevis, run behind the outer ankle bone. They stabilize the foot and ankle, assisting in outward movement and helping protect against sprains.
Common Reasons for Outer Foot Pain
Lateral ankle sprains are a common cause of outer foot pain. They occur when the ankle rolls outward and the foot turns inward, stretching or tearing outer ligaments. Symptoms include pain, swelling, and bruising around the outer ankle, often making weight-bearing difficult.
Peroneal tendinopathy, inflammation or degeneration of the peroneal tendons, is another common cause. These tendons run along the outside of the ankle and foot. The condition often develops from overuse or repetitive activities, causing pain, swelling, and sometimes warmth behind the outer ankle bone.
Stress fractures, caused by repetitive stress, can also cause outer foot pain. The fifth metatarsal, connecting to the little toe, is a common site, especially for a “Jones fracture.” Repetitive activities like running can overload the bone, leading to pain that often worsens with activity and improves with rest. Cuboid bone stress fractures are less common but possible.
Less Frequent Causes of Outer Foot Discomfort
Cuboid syndrome occurs when the cuboid bone shifts slightly out of alignment. This can cause a deep ache or sharp pain on the outside of the foot, sometimes extending to the arch. It may occur suddenly after an ankle sprain, or gradually from overuse or excessive inward foot rolling.
Nerve entrapment, like of the sural nerve, can cause outer foot discomfort. This occurs when a nerve on the outside of the foot is compressed, leading to burning pain, numbness, or tingling. Though less common, nerve compression can significantly impact sensation.
A Tailor’s Bunion, or bunionette, is a bony prominence at the base of the little toe, on the outside of the fifth metatarsal head. Symptoms include a visible lump, pain, swelling, and redness, often aggravated by narrow or poorly fitting shoes.
Various forms of arthritis can affect outer foot joints, causing pain and stiffness. Inflammation or degeneration in these joints leads to discomfort, especially with movement or weight-bearing. This pain can be persistent and worsen as the condition progresses.
Knowing When to Consult a Professional
While minor foot pain may resolve with rest, certain signs warrant medical evaluation. Seek professional help if pain is severe, sudden, or prevents walking or weight-bearing. Significant swelling, bruising, or infection signs like warmth, redness, or pus also require immediate attention.
Persistent pain not improving after several weeks of home treatment, or swelling not subsiding within days, warrants a healthcare visit. If you experience burning pain, numbness, or tingling, especially if it spreads, seek professional evaluation. A medical professional ensures accurate diagnosis and an appropriate treatment plan.