Sesamoiditis: Big Toe Pain That’s Often Misdiagnosed

Pain under the big toe joint can be one of the most frustrating problems in the forefoot. For many people, it feels like walking on a small pebble or bruised bone at the ball of the foot. They may be told it is a bunion, arthritis, or “just a bruise,” but often the true culprit is sesamoiditis.

At My Family Podiatry we see this condition regularly, especially in active patients, runners, and people who spend long hours on their feet. The tricky part is that sesamoiditis is often misdiagnosed, which delays proper treatment. In this blog we will explain what sesamoiditis is, why it happens, how it is often confused with other problems, and what treatments can help you get back to pain free movement.

What Are Sesamoid Bones?

The sesamoid bones are two small, pea-sized bones located under the big toe joint, embedded in the tendon of the flexor hallucis brevis muscle.

Their job is to:

• Act as pulleys for tendons, improving leverage when pushing off the ground.

• Absorb and distribute weight through the forefoot during walking and running.

• Protect the tendons beneath the big toe joint.

Even though they are small, they bear enormous loads. Every step you take places pressure on them, particularly when running, jumping, or pushing off on the big toe.

What Is Sesamoiditis?

Sesamoiditis is inflammation or irritation of the sesamoid bones and surrounding soft tissue. It is a type of overuse injury that develops gradually.

Symptoms typically include:

• Pain under the ball of the foot, just beneath the big toe.

• Pain that worsens with activity, particularly running or jumping.

• Tenderness when pressing directly under the big toe joint.

• Swelling or bruising in some cases.

• Difficulty bending or straightening the big toe without pain.

The pain can be sharp, aching, or feel like a deep bruise. Many people describe it as walking on a stone or lump.

Why Is Sesamoiditis Often Misdiagnosed?

Because pain in the big toe region can come from several causes, sesamoiditis is often confused with:

• Bunions (hallux valgus): Pain is usually on the side of the joint, not under it.

• Arthritis of the big toe (hallux rigidus/limitus): Pain is linked to stiffness and reduced motion, rather than tenderness underneath.

• Metatarsalgia: General forefoot pain may be mistaken for sesamoiditis without precise testing.

Without thorough assessment, including imaging when appropriate, patients may be left trying treatments that are not suitable.

Diagnostic Ultrasound and Imaging

At My Family Podiatry we use in-clinic diagnostic ultrasound to examine the sesamoid bones and surrounding soft tissues. This allows us to:

• Confirm if irritation is present in the sesamoids or surrounding tendons.

• Detect swelling, degeneration, or scar tissue.

• Differentiate between sesamoiditis, a stress fracture, or other forefoot conditions.

• Monitor changes over time as treatment progresses.

In some cases, X-rays may also be ordered to confirm or rule out fractures. The combination of physical examination and imaging gives us a clear picture, reducing the risk of misdiagnosis.

Bipartite Sesamoids: A Common Source of Confusion

A bipartite sesamoid is when one of the sesamoid bones forms in two separate pieces instead of fusing into one. This is a normal variation and is present in around 10 to 15 percent of people.

While usually painless, bipartite sesamoids can:

• Increase the risk of irritation and sesamoiditis because the two bone segments move slightly against each other.

• Be mistaken for a fracture on imaging, particularly after a sudden injury.

• Lead to unnecessary worry or inappropriate management if not recognised.

By using ultrasound and correlating findings with your symptoms, we can tell the difference between a bipartite sesamoid and a true fracture. This ensures you get the right treatment for the right problem.

Risks of Training on Damaged Sesamoids

Continuing to run, train, or play sport on painful sesamoids is risky. What may start as irritation can quickly escalate into more serious injuries such as:

• Sesamoid stress fractures: Tiny cracks in the bone caused by repetitive overload. These can be difficult to heal if ignored.

• Complete sesamoid fractures: A full break of the bone, usually painful and limiting. Recovery time is much longer and immobilisation is often required.

• Avascular necrosis: In severe cases, the blood supply to part of the sesamoid is disrupted, leading to bone death in that segment. This is a serious complication and much harder to treat.

Pushing through pain rarely works in your favour. Early diagnosis and treatment prevent these complications and allow for a faster, safer return to activity.

Risk Factors for Sesamoiditis

Certain activities, foot types, and footwear increase the risk of developing sesamoiditis:

• High impact sports: Running, dancing, basketball, football, and tennis.

• High arches or flat feet: Both change pressure distribution under the big toe joint.

• Tight calf muscles: Increase forefoot load during push off.

• Footwear choices: High heels, stiff-soled shoes, or thin minimalist footwear.

• Occupational stress: Long hours on hard surfaces in unsupportive shoes.

How We Diagnose Sesamoiditis

Our assessment includes:

• Locating the exact site of tenderness.

• Testing big toe motion and function.

• Analysing foot posture and gait.

• Reviewing footwear.

• Performing ultrasound to confirm inflammation or rule out fracture.

This process helps us differentiate between sesamoiditis, fractures, arthritis, and other causes of forefoot pain.

Treatment Options

Rest and Load Management: Modify activities that cause pain, such as running or high-impact sport.

Footwear Adjustments: Supportive, cushioned shoes or rocker-soled designs to reduce pressure under the big toe.

Orthotics and Padding: Custom orthotics with offloading for the sesamoids. Cut-out pads to reduce direct pressure.

Strengthening and Stretching: Calf stretches and intrinsic foot strengthening to improve biomechanics.

Manual Therapy: Soft tissue release and mobilisation to reduce surrounding tension.

Shockwave Therapy: For stubborn cases, shockwave therapy can stimulate healing in the sesamoids and surrounding soft tissue.

Taping and Immobilisation: Short-term taping or use of a walking boot in severe cases.

Surgery (Rare): Reserved for chronic cases or persistent fractures not responding to conservative care.

Prevention Tips

• Choose supportive shoes with cushioning.

• Avoid high heels or thin-soled shoes for long periods.

• Increase training loads gradually.

• Stretch and strengthen the calves and feet.

• Seek early podiatry assessment for forefoot pain.

When to See a Podiatrist

If you have persistent pain under your big toe joint, don’t ignore it. Pain lasting more than a week, worsening with activity, or interfering with walking should be assessed.

With the right diagnosis and management plan, most people recover well. Leaving it too long risks turning a manageable irritation into a stress fracture, complete fracture, or even avascular necrosis.

Conclusion

Sesamoiditis may involve the smallest bones in your foot, but it can cause significant pain and disruption. Because it is often misdiagnosed as bunions, arthritis, or even fractures, proper assessment is essential. At My Family Podiatry we use diagnostic ultrasound to examine the sesamoids, detect inflammation, and rule out more serious issues like stress fractures. We also recognise variations like bipartite sesamoids, which can increase irritation or be mistaken for fractures.

With targeted treatment, from footwear changes and orthotics to shockwave therapy and strengthening, most people recover well and return to activity.

If you are struggling with pain under your big toe, book an appointment with My Family Podiatry today. Our team will get to the root cause and help you move pain free again.

Book An Appointment