My left foot hurts outside of the 5th metatarsal. It hurts to walk but after ice & using foot massager it feels better. It feels better after I run.

Peroneal Tendonitis. The Peroneus Brevis muscle attaches to the base of the 5th metatarsal and often is the problem with pain in that area of the foot. Ice and massage lowers inflammation and loosens up the tendon. It usually will ge worse with first steps after sitting awhile or sleeping all night. Running probably warms the muscle/tendon up and increases bloodflow which would then make if feel better.