Hey there, good luck with this one, I've had varying levels of sesamoid issues in the past (two breaks and one bruise).
If you've had an MRI or CT and you know for sure it's a bruise then great, probably just 4 weeks without running.
If you've not had one, I'd be very cautious - I've had two breaks and it took the latter one 26 weeks to repair, my experience was that a bruise and a break feel the same.
During my bruise injury (which was after the two breaks), I finally got some orthotics. They are made from fairly simple plastic and not rigid - they bend well, light and are very small. They fit in most shoes (except spikes) and they don't feel like regular rigid carbon orthos which I've had an were a joke. They have offloaded the ball of my foot nicely and I've had (touch wood) no issues for 24+ months.
During rehab, for two weeks I rowed, cycled and swam, even the cross trainer would hurt a little so I skipped that. I made myself some bodge orthotics whilst my new ones were being prepared, just two insoles back to back with a giant hole in the bottom one. They enabled me to run for 5-10 mins every other day after cycling after the initial 2 weeks. After 4-5 weeks I risked running again, I got away with it, even though the doc had told me no runs for 8 weeks. After 8 weeks I was over 50 miles/week again which is better than 0!!!
Good luck and if you want to chat. try me on
m.n.ryall@talk21.com
Foot.