DO YOU HAVE ANY SESAMOID BONES? by John Post, MD

“Give me three steps, gimme three
steps mister…” Lynyrd Skynyrd

I was asked recently about an
athlete with a foot problem and a possible sesamoid fracture. It occurred to me
that most folks didn’t know they had sesamoid bones, or if they did, where they
were.

The simplest definition of a sesamoid bone is one that’s
surrounded by tendon or intratendinous. The most obvious example would
be the knee cap. This blog will be devoted to the pair of sesamoid bones
underneath the ball joint of the big toe. They are about the size of a lima
bean, normally glide front and back with each stride and rarely give us much
cause for concern. But as with any bone in the foot, they can be broken or
subject to a stress fracture. A true fracture takes a pretty significant injury
such as a fall from a height where we in the endurance sport world are more
likely to see a stress fracture from the usual causes. (See my two recent blogs
on this injury pattern.) The athlete with a true fracture is going to be
immobilized between 4 and 8 weeks, will be made non-weight bearing

on crutches, and like likely be doing all of his/her training in the pool

for a while.  Treating the stress fracture is much less aggressive, but

here, too, your running shoes will see no action for longer than you’d like.

Often times, sesamoid problems present as sesamoiditis, an inflammation

of the area caused by the usual culprits of too much too fast, especially

speed work or hills. One starts with the gradual onset of pain under the big

toe, initially present during only the hardest portion of the workout and

increasing to any running, even walking. There doesn’t seem to be much

redness or bruising. They can be slightly swollen but frequently it’s not

easy to see.

So what do you do?
Back off for a while. Maybe do a percentage of your weekly run volume in the
pool. (It can be fun.) Then, if you can unload the area of distress by using a
metatarsal pad or other device to very slightly overload the non-injured portion
of the foot being certain to ice down the area once the run is over. Don’t be so
aggressive that you risk frostbite but 15-20 minutes ought to do
it.

Lastly, trying to go through your log book examining each week, each
run, for clues as to the cause and how to never have it again is always
beneficial.  And if you’re successful, your “three steps” will be crossing the
finish line without pain!

John Post, MD