Sesamoids are tiny bones embedded in a tendon that allow the tendon to slide smoothly for ease of mobility. In the foot, there are two sesamoids underneath the top of the foot and near the big toe that allow the big toe to move up and down freely. These help with push-off activities such as walking, running, and climbing.

Since the sesamoids are exposed to excessive force and pressure during weight-bearing activities, sports, and exercises, they are often prone to injury and trauma, as well as stress from overuse or from standing on hard surfaces for prolonged periods. Sesamoids can fracture or become inflamed. Sesamoiditis, a form of tendonitis, occurs when the sesamoids become inflamed, usually due to pressure placed on the balls of the feet.

What Are Some Causes of Sesamoiditis?

• Weight-bearing sports, such as running, particularly on inclined surfaces or for long durations of time
• Ballet and playing the position of catcher in baseball, which are activities that put recurring pressure on the balls of the feet
• Having naturally high-arched feet or wearing high-heeled shoes

What Are Symptoms of Sesamoiditis?

• Pain in the ball of the foot or under the big toe that worsens during recurring pressure or walking barefoot
• Localized swelling and bruising
• Stiffness, pain, and difficulty when bending and moving the big toe

How Is Sesamoiditis Treated?

• Stop the activity that involves pressure to the area
• Wear supportive, cushioned, soft-soled, low-heeled footwear
• Ice the area
• Take over-the-counter anti-inflammatory medications on a temporary basis (ask your doctor first)
• Brace the area to allow for healing
• Receive a steroidal medication injection to alleviate swelling