Letrozole

Pain in balls of feet can be due to plantar fascists. Typical symptons are equisite pain in the ball of foot after resting. 

Here are some exercises that help it. I've had it 3 times in my life as I was an avid walker. All the rest during chemo finally cured mine. Haha. But the exercises made recovery so much quicker than resting alone plus a heel pad...lots on the market. If you google you will understand how it happens.

http://footlogics-shop.com.au/page/28/Plantar-Fasciitis-exercises

If no improvement hsve a tefferal to a physio as sonetimes a splint is needed. 

I've been on letrozole for nearly five years - my feet are a bit weird but that was caused by taxol, before I started on letrozole. No harm in mentioning it to your oncologist, just in case. It may of course be entirely coincidental, we always assume everything is a direct result of treatment, but all the more reason to get it checked. 

Hi Jovanol..yes a typical side effect.gentle.exercise most important
i have found that flexing feet before standing makes walking easier
Also use gel inners soles ..even use flight socks
I have also developed plantar faciaitis which i d I d not have before starting
Less body fat is imp 

Hi Jovanovl. I am not sure about this one.??  I have been on Letrozole for 4 months with side effects but not what you have. I also have osteoporosis.  I was getting acking bones all day long until I changed my medication to night time and also took magnesium. Not sure if this will help but certainly worth a try. Good Luck and hope something works for you. T :-)