San Francisco Podiatry Video


Tuesday, November 22, 2011

Sesamoid injury in a runner?

I recently got from a question from a runner who had been ramping up for the California International Marathon in Sacramento and started having pain in the ball of the foot at the big toe joint...

"Hello Dr. Segler, I have been training for my first marathon and read that hills would be a great way to get super strong. I really wanted to do well and finish in under four hours so I started do hill repeats on Fillmore Street in San Francisco. Things were going great and I really felt like all the training was starting to pay off. Then one morning I got up and noticed this little aching pain in the bottom of my big toe joint every time I stepped on my right foot. It seemed to be worse on the hard tile in the kitchen. I have been really ramping up the miles and I am worried that this may be a stress fracture. Can you tell me the best way to tell if this is a stress fracture or something else? It hurts right in the ball of the foot under the big toe joint. Here is a picture of where it seems to hurt the most. Thanks!"

Great question! And thanks for sending the pic.. Here is your answer...

Pain in the ball of the foot can occur under the big toe joint for several reasons. Based on your description and the location of the tenderness, I would be most worried about the following conditions:

1. Sesamoiditis: inflammation of the sesamoid bones under the big toe joint (first metatarsophalangeal joint). You stand on these two little bones. Because they get stressed more when you run uphill, you may develop sesamoiditis when doing lots of hill repeats. If you push right on the hard little bones, and one hurts more than the other, it is probably sesamoiditis.

2. Flexor Hallucis Longus tendinitis (FHL tendonitis): strain, inflammation and/or micro-tearing of the tendon that pulls the big toe down against the ground allowing you to push off when you run. The sesamoid bones are actually embedded within the FHL tendon. If you push right under the big toe joint and the whole area is tender (and doesn't really hurt more on one specific sesamoid bones) it may be FHL tendonitis. If you pull upward on the big toe (away from the ground) you will stretch the FHL tendon. If this hurts, FHL tendonitis is likely.

3. Sesamoid Stress Fracture: a tiny little crack in one of the sesamoid bones from too many hill repeats and or too much running volume. If this is the cause of your foot pain, it will hurt more on one sesamoid than the other, it will also hurt when you pull the big toe upward, and your foot will most likely be swollen and/or bruised. The best way to diagnose a stress fracture of the sesamoid bone is with an MRI. X-rays don't always show stress fractures right away. X-rays will only show a stress fracture in a sesamoid that has fractured or completely cracked. Based on your story, however, this seems unlikely.

Get better as fast as possible and good luck in your marathon!

Learn more about sesamoiditis, FHL tendonitis and sesamoid stress fractures at

Dr. Christopher Segler is a nationally recognized expert on running biomechanics and foot surgery. He has been invited to lecture to foot surgeons, sports medicine doctors, podiatrists, triathletes and runners in training all over the United States, as well as Canada, New Zealand, Portugal and Turkey. If you have foot pain caused by a running injury, you can send a picture of where it hurts and a brief description to him. Your picture and answer to your question will then be posted on our blog so others can learn how to deal with running injuries as quickly as possible and keep running pain free. You can email your pic and question to If you have a quick question about a running injury and you are not in San Francisco, you can actually call him directly as 415-308-0833. He schedules house calls for runners and triathletes in San Francisco, Marin and the East Bay through