There is a very simple and effective treatment for muscle spasms and sore muscles in general-magnesium.
Modern diets are very low in this and it is absolutely vital for muscles.
Do a bit of research if you like.
I can strongly recommend magnesium oil/ chloride. I take it diluted in water and swear by it.
The 'oil' is in fact only concentrated deep sea water rich in magnesium-nothing scary.
You can also get a powder which is not as fast acting, but don't waste money on pills as they are too weak.