Two pea-sized bones, called sesamoids, are embedded within the soft tissues under the main joint of the big toe. Even though they are small in size, the sesamoids play an important role in how the foot and big toe work. If the sesamoids are injured, they can be a source of severe pain and disability, causing the condition sesamoiditis.

Sesamoid = the bone affected.

Itis = inflammation or swelling of..

Sesamoid anatomy

Sometimes known as the “ball bearings of the foot,” the sesamoids are two small bones found beneath the first metatarsal bones The main joint of the big toe forms the inside edge of the ball of the foot. The two small sesamoid bones are located on the underside of this joint. There is one sesamoid bone on each side of the base of the big toe.

The muscles that bend the big toe down (the toe flexors) pass underneath the main joint of the big toe, crossing over the bump formed by the sesamoid bones. This bump acts as a fulcrum point for the toe flexors, giving these muscles extra leverage and power. The sesamoids also help absorb pressure under the foot during standing and walking, and they ease friction in the soft tissues under the toe joint when the big toe moves.

Sesamoid pain can develop a number of different ways. When the tissues around the sesamoid bones become inflamed, clinicians call the condition sesamoiditis. Sesamoiditis is often caused by doing the same types of toe movements over and over again, which happens in activities like running and dancing.

Sesamoid Fracture Can cause pain in the sesamoids and associated sesamoiditis. Fractures can occur when a person falls and lands bluntly on the ball of the foot.

Stress fractures can also occur in the sesamoid bones. Stress fractures are usually caused by the strain of overworking the soft tissues. Athletes most often suffer stress fractures of the sesamoids because of the heavy and repeated demands that training places on the soft tissues of the foot and big toe.

Arthritis can develop where the sesamoids glide under the bone of the big toe. The sesamoid bones create a joint where they move against the bone of the big toe. Like other joints in the body, this joint can also develop arthritis. Arthritis is more likely to be a problem in people who have high arches in their feet. The high arch causes the main joint of the big toe to become rigid. This focuses strain and pressure on the sesamoids.

Osteochondritis can lead to sesamoiditis. In some cases, blood supply to the sesamoid bone is decreased. This condition is called osteochondritis. Osteochondritis causes a piece of the bone to actually die. The body’s attempts to heal the area may build up extra calcium around the dead spot.

People with sesamoiditis usually feel vague pain under the main joint of the big toe. The sesamoids typically feel tender when touched. Movement of the big toe is often limited. People tend to notice pain mostly when their big toe is stretched upward, which can happen when the back foot pushes off for the next step. Occasionally the joint catches or pops. The catching or popping is often followed by increased pain, which usually eases after resting. Some people report feelings of numbness in the web of the first two toes.

sesamoiditis treatment for runners and other athletes in the acute phase

Ice packs and compression bandages are excellent to reduce pain and swelling

Sesamoiditis restoring normal function

Once the acute symptoms have settled down do nothing for 3-4 weeks to allow the sesamoid to heal.

Once the healing process has taken place it is necessary to rehabilitate the affect leg.

Video showing how to use rehab band (whole body).

Sesamoiditis – hamstring stretches

Why stretch the hamstrings when sesamoiditis is the problem? Tight hamstrings causes the knee to stay flexed throughout the gait cycle. This has the ‘knock on’ effect of overloading the front of the foot by causing early heel lift in the gait cycle. Tight hamstrings are one of the major causes of this problem that goes undetected.

Sesamoiditis – muscle strengthening exercises

Foot muscles -strengthening

To have the best chance of a rapid recovery it is a good idea to strengthen the muscles in the foot, ankle and legs. This will help to take unwanted stress off the sesamoids. The single best exercise to improve strength of the muscles around the foot ankle is eccentric loading. This is usually done none weight bearing, however the use of a wobbleboard is an excellent way to strengthen muscles around the foot and ankle in a controlled and gentle manner. It also has the added benefit of improving proprioception too. Proprioception is the nerve connection from the brain to the foot. This is often damaged/ disrupted after injury and can increase the chances of injury from recurring. It can also significantly delay recovery.

The way we function biomechanically is predominantly controlled by genetics, its hereditary (runs in the family).

The is the cheapest and most cost effective way for any athlete to reduce the risks of injury from occurring and to prevent re-injury is follow our checklist below. Overall costs for the average athlete will run into pennies per mile/hour of sport.

1. Check your footwear

Are your running shoes worn and in need of replacing? If so change them. Sesamoiditis is often caused by high impact forces so a good shock absorbing shoe is a must. For more advice on running trainers our running shoe advice page is worth reading. Read more->

Below are a selection of trainers that are ideal for athletes.

Trainers for a neutral/ under pronating foot type

Our clinicians see many patients with a rigid or under pronating foot type. Whilst this is generally the best of the foot types to have, due to its rigid nature, shock absorbency is poor. Therefore we recommend trainers with as much shock absorbency as possible. Luckily the leading manufacturers provide excellent shock absorbing running shoes.

Trainers for over pronators

Our team recommend motion control trainers for our patients with over pronation. They are one of the most important things that an athlete can do to help rectify this biomechanical problem by themselves.

2. Rectify poor biomechanics with orthotics if necessary

The way your foot strikes the ground and the forces that are placed on it can have a direct effect on sesamoiditis and can also delaying healing times. Check our biomechanics page for detailed information. Read more->

Bespoke Orthotics

Think you require bespoke orthotics for your sesamoid symptoms? Visit our sports podiatry clinic pages for a clinic near you.

3. Strengthen weak foot and ankle muscles

4. Improve shock absorbency

Sesamoiditis can be made markedly worse by high impact forces being directed through the forefoot, particularly in running activities. Purchasing some shock absorbing insoles is a cheap and effective way of vastly improving shock absorbency and reducing unwanted ground reaction force. These little pads slip into the shoe and are not noticed by the athlete when partaking in sport.

Sesamoiditis injury prevention checklist summary

• Rectify Biomechanics if necessary
• Check Running shoes
• foot and ankle strengthening
• Improve shock absorbency