The Sesamoid Bones Explained

In brief: The sesamoid bones are two small bones embedded in the tendon beneath the big-toe joint. They act like pulleys that help the big toe push off and protect the joint from pressure, making them important during the final drive of each stride.

What are the sesamoid bones?

The sesamoid bones are two small bones, each roughly the size of a pea, set within the tendon under the big-toe joint at the ball of the foot. Unlike most bones they are not connected at a typical joint; they sit inside the tendon itself.

Why they matter

The sesamoids act like pulleys, giving the big-toe tendon better leverage so the toe can push off powerfully. They also help spread and absorb pressure at the ball of the foot, protecting the joint above them.

How they work

As you push off, the big toe bends and the sesamoids glide beneath the joint, allowing a smooth, strong final drive. They bear significant load because so much push-off passes through the big toe.

What to look for

Forefoot cushioning and enough room at the ball of the foot help take pressure off the sesamoids. A shoe that bends at the right point supports a smooth toe-off.

The sesamoid bones and your running kit at OD's

Forefoot cushioning eases pressure under the big toe. The team in St Helens can help you find shoes with comfortable forefoot padding, and we offer next-day delivery and free click and collect.