Wednesday, July 19, 2006

this is what is wrong with my feet
Neuroma (Morton's Neuroma)

Description: A Neuroma, or Morton's Neuroma, is a benign soft tissue mass that forms on the nerve which runs between the metatarsals, in the ball of the foot. When two metatarsal bones rub together, they pinch the nerve that runs between them. This repeated pinching, or repeated injury to the nerve, will cause the nerve to swell, and eventually a benign mass occurs at the site of the repeated injury. This mass is known as a Morton's Neuroma (named after the physician who first described this mass, in 1876).

Symptoms: The most common symptoms of a neuroma may include:
pain in the ball of your foot radiating to adjacent toes.
neuromas can form between all of the metatarsal heads and toes, but the most commonly affected area is between the 3rd and 4th metatarsal heads and toes.
the pain can be sharp, burning, or tingling in nature.
the pain is usually present only when wearing shoes, and gradually goes away when the shoes are removed.
numbness in adjacent toes.
swelling of the area.

Causes: A Morton's neuroma forms when two adjacent metatarsal heads rub together in the ball of the foot. The nerve that lies between these bones is thus pinched and irritated; and, if this pinching continues, a neuroma (benign nerve mass) eventually forms. In the normal foot, the five metatarsals are held tightly in place, in a precise relationship to each other, so that they do not rub together. In the Morton's neuroma foot type, the ligaments and tendons which hold the metatarsals in their normal positions are more flexible (lax) than normal. This abnormal flexibility may be a result of: biomechanical foot defects that we inherit from our parents, the weakening of muscles and ligaments caused by advancing age, or injury. A closer look at these causes of Morton's Neuroma is necessary if we are to understand how these masses can be prevented and treated: Biomechanical Foot Defects are those defects that we are born with, which predisposes us to Morton's Neuroma:
Hyper-Flexible Feet: The normal foot is made up of bones and joints that are held firmly together in a precise relationship. When the ligaments and tendons which hold the bones and joints together are more flexible (lax) than normal, the metatarsals are able to drift towards each other. When this occurs, the metatarsals rub together and pinch the nerve that lies between them. This abnormal flexibility is usually a result of the genes we inherit from our parents.
Age-Related Changes of Ligaments Muscles, and Tendons: As people age, the ligaments, muscles, and tendons of the foot begin to lose strength, and become thinner. As the aging process progresses, these structures cannot always hold the metatarsals in their normal positions. If this occurs, the metatarsals may begin to drift towards each other and pinch the nerve that lies between them. Again, if this is allowed to continue, a Morton's Neuroma may form.
Injury: The two classes of injuries which may contribute to the formation of Morton's Neuroma are:
Macro-trauma. An example of this type of injury would be a broken metatarsal bone which does not heal straight, and is bent towards the adjacent metatarsal. This situation may allow the metatarsal heads to rub together and pinch the nerve between them.
Micro-trauma. An example of this type of injury would be a woman’s dress shoe with a pointed toe. These shoes are narrow across the ball of the foot and squeeze the metatarsals together. After thousands of steps in this type of shoe, the nerve between the metatarsal heads may become pinched, inflamed, and painful. Eventually a neuroma may form on the nerve.

Self-Treatment and Prevention:
The old adage, "An once of prevention is worth a pound of cure," is most appropriate when trying to prevent a Morton's Neuroma from forming, or when treating a neuroma in its earliest stages.
Long Term Treatment/Prevention must be directed towards:
Preventing adjacent metatarsal heads from rubbing together and irritating the nerve that lies between them.
Maintaining the individual bones, joints, muscles, ligaments, and tendons of the Hyper-Flexible Foot and Aging Foot in a normal alignment. This will prevent the metatarsals from drifting towards each other and irritating the nerve between them.
Providing shock absorption to the ball of the foot. This will help to support and protect the metatarsal heads and the nerves between them. As we age, the protective fatty pad on the ball of the foot becomes thinner, and cannot act as a shock absorber for the sensitive nerves and other structures in the ball. Thus, the tremendous forces exerted on the foot with each step we take are passed on to the nerves and bones, rather than being absorbed by the fatty pad. Eventually, these forces could help to irritate the nerves in the balls of the feet, causing a Morton's neuroma to form.



1 comment:

Brian said...

I had a broken toe earlier this year and after my front wheel picked up a rock and tossed it onto my foot, I had to pull out due to extreme pain. Yes, though I have been racing off-road 11 years now, I quit. Contrary to popular opinion I am not a podiatrist, so I couldn't heal myself. Foot pain is a bitch!