Sesamoiditis is a condition affecting the small bones located at the base of the big toe. These bones, called sesamoids, are unique because they are embedded within tendons, similar to how the kneecap is located in the quadriceps tendon. The two sesamoid bones are pea-sized and sit on the underside of the forefoot, beneath the head of the first metatarsal. They function like a pulley system, providing leverage for the big toe to push off during movement. The condition involves inflammation and irritation of these bones and surrounding soft tissues, resulting from excessive pressure or strain.
Causes and Risk Factors
Sesamoiditis is typically an overuse injury, developing when repetitive stress on the forefoot exceeds the capacity of the sesamoid bones and their attached tendons. This continuous loading causes small injuries and leads to chronic inflammation. The condition is common among individuals who engage in high-impact activities that require frequent weight-bearing on the balls of the feet, such as running, ballet dancing, or basketball.
Wearing inappropriate or unsupportive footwear is another significant contributing factor. Shoes with insufficient cushioning, worn-out soles, or those that concentrate pressure on the forefoot, like high heels, increase the strain on the sesamoid bones. Sudden changes in activity level, such as quickly increasing training intensity or duration, can also overload the area before the tissues have time to adapt.
A person’s foot structure can also predispose them to this condition. Individuals with high arches or a rigid foot anatomy may experience increased pressure on the sesamoid area. Conversely, those with excessive foot pronation or flat feet can also put undue stress on the sesamoids.
Identifying the Symptoms
The hallmark of sesamoiditis is pain located specifically in the ball of the foot, directly underneath the big toe joint. Unlike a sudden fracture, the pain usually has a gradual onset, beginning as a mild ache that intensifies slowly over several weeks or months. The discomfort can range from a dull, persistent ache to a sharper, throbbing sensation.
Pain is consistently exacerbated by movements that require the big toe to bend upward, such as pushing off the ground while walking or standing on tip-toes. Difficulty putting weight on the ball of the foot is a common complaint. Mild local swelling and tenderness to the touch may also be noticeable around the affected area.
The pain tends to subside when the foot is rested, but it returns promptly upon resuming an aggravating activity. This pattern of pain that worsens with activity and improves with rest is a key indicator of chronic sesamoiditis, distinguishing it from the immediate, sharp pain of a fracture.
Treatment and Recovery Steps
Initial management focuses on reducing inflammation and removing the pressure causing the irritation. This includes resting the foot by temporarily stopping high-impact activities that aggravate the pain. Applying ice to the sole of the foot for 10 to 15 minutes several times a day minimizes swelling and discomfort.
Offloading pressure from the sesamoid bones is a fundamental step in recovery. This is achieved using specialized orthotic devices, such as cushioned pads or inserts with a cutout design, to redistribute weight away from the painful area. Wearing stiff-soled, low-heeled shoes also limits motion in the big toe joint, reducing strain on the sesamoids.
Taping the big toe to keep it slightly bent downward restricts movement and provides additional support to the tendons. For more persistent cases, a healthcare provider may recommend immobilization using a removable walking boot or brace for four to six weeks to allow the inflammation to fully resolve.
Recovery timelines vary; mild cases improve within a few weeks, while chronic issues may require several months of conservative treatment. If symptoms do not improve, or if a fracture is suspected, a medical consultation is necessary. This may involve imaging tests like an X-ray or a steroid injection to reduce severe inflammation.