Direct Injury to The Sesamoid Bones
Many times sesamoiditis can be caused simply by aggravating the sesamoid bone through brunt force trauma such as stepping on a hard object or running without shoes. This cause is relatively rare, but is seen in certain cases.
Another method of injuring the sesamoids is through “Micro-Trauma.” Micro-Trauma is caused by overuse of the sesamoid area, which is positioned just above the ball of the foot. A person who engages in repetitive activities which require extensive time on the balls of their feet may develop sesamoid micro-trauma. Some examples of such activities include:
- Squatting (Think a catcher’s stance)
- Running or Leaping on the balls of the feet
- Wearing heeled shoes for extended periods
Age Related Causes
As with any other part of the body, age takes a significant toll on the sesamoid bones. Conditions such as osteoperosis can contribute as a cause of sesamoiditis. Osteoarthritis is also known to assist in the onset of sesamoiditis.
Osteoporosis: As the bones lose calcium and in turn become weaker, the sesamoids may not be able to handle the continual stress that is placed on them during every day activities. When this occurs, the sesamoid bone begins to develop small stress fractures, which in turn cause inflammation, swelling and pain.
Osteoarthritis: This condition may cause the formation of miniature bone spurs on the sesamoid bone. The spurs themselves act as an irritant to the surrounding tendons that hold the sesamoid bone in place. The result of course is inflammation, swelling and pain.
As with any ailment, there are certain people who are either born with or otherwise genetically predisposed to sesamoditis. You will find below some common defects that are directly related to sesamoditis:
Enlarged Sesamoid Bones: A person born with enlarged sesamoid bones will realize the pain from their first day walking. The increased size of the bones causes them to attract a disproportionate amount of body weight during each step. This excessive weight distribution will eventually lead to deterioration, which in turn leads to inflammation and pain.
Overpronation: Overpronation is a condition whereby a fallen or collapsed arch causes a person’s ankle to roll inward with each step. I am not an expert on overpronation, but you may want to read the article What is Overpronation. I found it to be very comprehensive and informative. What I do know is that this act of rolling inward with each step puts undue stress on the ball off the foot and big toe. The excess use can cause micro fractures and/or irritation.