I think I found my problem!
Excerpted from: www.mayoclinic.com/health/metatarsalgia/DS00496
The main symptom of metatarsalgia is pain in the ball of your foot... The pain may be sharp, aching or burning. Other symptoms may include:
- Sharp or shooting pain in your toes,
- Numbness or tingling in your toes,
- Pain that worsens when you flex your feet. [Pushing off with my toes?]
Often, several factors are involved, including:
- Intense training or activity. ... Training intensely or for long periods puts even more stress on the metatarsals, often leading to chronic irritation and inflammation. [Training for Big Sur, maybe?]
- High heels, which cause more weight to be transferred to the front of the foot, are one of the most common causes of metatarsalgia in women. [Every day...]
Treatment includes: rest, ice, ibuprofen, wearing proper shoes and inserts.
So, I'll wear flats for a while, avoid speed workouts, take ibuprofen and ice my foot. [Yuck!] At least it doesn't involve sitting in ice water - that's much worse!