The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
Spasms can be dealt with with pressure, deep breathing, and contract relax work with a little ball in the area. A lacrosse ball my be too aggressive if the spasm is pretty tender so plan accordingly. You will probably come across more of this as you move through the course. The bigger question is why does this person develop spasms in the first place? What type of training is occurring when the area spasms. What exercises flare it up? You will have to sort that out and see if there are technical/efficiency issues that can be addressed through coaching.
As far as your foot, that is a tricky one, but joint capsules for the toes are no different than any other joint capsule. Distraction and motion are the best places to start.