is an inflammation of one or both of the sesamoid bones in the first metatarsal
joint (the big toe). This causes pain and discomfort under and around the
joint. The big toe is a very important joint for locomotion as it is the last
point of contact with the ground during toe-off
What is a sesamoid bone?
sesamoid is an anatomical term given to a bone that sits within the tendon of a
muscle. The most commonly known sesamoid bone is the patella, which sits inside
the tendon of the quadriceps muscle. A sesamoid bone functions by providing a
mechanical advantage to a joint’s range of motion by increasing its lever arm.
An increase to the lever arm of a joint reduces the energy required by the body
to produce movement. So biomechanically speaking, sesamoid bones create more
efficient movement. The foot has two common sesamoid bones, located at the base
of the head of the first metatarsal (The ball of the foot at the big toe).
These bones are located in the tendon of the muscle flexor hallucis brevis,
which is a small muscle responsible for pushing the big toe into the ground,
particularly during the toe-off phase of walking.
word sesamoid derives from the Greek translating of “sesame-seed like”
identifying the small, smooth structure of the bones.
Why are there sesamoid bones in my feet?
sesamoid bones are very important to the function of the foot as they help
absorb impact and increase the forces generated through movement. The bones act
similarly to pulley, increasing the leverage of tendons and forces produced by
the position of the sesamoid bones in the foot and their role, the sesamoid
bones are put through a lot of pressure during locomotion. Large increases in
training load or movement put a lot more pressure through the sesamoid bones
and this leaves them prone to injury.
What is Sesamoiditis, how does it happen?
common ailment affecting the ball of the foot and big toe, sesamoiditis is the
condition when the sesamoids become inflamed or irritated.
are a number of factors which can contribute to the development of sesamoiditis
- Poor Biomechanics/Malalignment can
cause of overload of the sesamoid bones and surrounding soft tissue. Both
collapsed and high arches can contribute to the development of symptoms.
- Acute overtraining or
sudden increases in training load will increase forces travelling through the
feet before the structures can adapt and manage them. This can cause
inflammation and overuse injuries of the sesamoid bones.
- Trauma to the
ball of the foot, such as landing from a height, can cause inflammation or
fracture of the sesamoids.
- Poorly Fitting or Inappropriate
Footwear can cause poor alignment or increase pressure
through the sesamoids. This is common when consistently wearing hard-soled or
Signs and Symptoms of Sesamoiditis?
symptoms associated with sesamoiditis are quite clear and when reported to a physiotherapist
will lead to a quick diagnosis.
primary symptom of sesamoiditis is pain under the base of the big toe. Pain
experienced from sesamoiditis progresses gradually as opposed to an immediate
onset indicating fracture.
pain will be experienced when the bending and straightening the big toe. As the
condition progresses, the area under the big toe will become tender with any
longstanding cases patients may report pain all the time. The pain
is usually worse when the patient is on their feet. There may
also be swelling, bruising or inflammation of the area.
How to Treat Sesamoiditis?
the first step in treating sesamoiditis is diagnosis. Whilst an assessment of
symptoms is usually sufficient to diagnose the injury, medical imaging (x-ray,
ultrasound, or CT scans) may be necessary to evaluate the severity and optimal
diagnosed, sesamoiditis is typically treated by addressing the cause of pain.
Treatment is usually conservative, however, if unsuccessful, then surgical
intervention may be required.
will prioritise deloading the sesamoid bones and immediately stopping activity
which aggravates the injury. Application of ice and use of an oral
anti-inflammatory will help to relieve pain and can be used in conjunction with
immobilization strapping to initially treat the disease.
of a foam pad and soft, low heeled shoes are also recommended. Our physiotherapist
will also develop a gradual return-to-activity program to ensure correct
recovery and prevent recurrence of pain.
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