Soaper_Gal
For pain, I really like lavender and nutmeg. Muscle tightness, I'm not sure because I've never used any particular EO for muscle tightness, usually just any EO in a base and massage away.
For specific ones, may I suggest you use google or yahoo and do a search on the following words "essential oil muscular sclerosis".
I am sure you will get many, many websites with information specific to your needs. But for the pain, I can say lavender and nutmeg helped me tremendously when I've needed it. I used lavender in hot baths, castor oil packs, massage oils and nutmeg in castor oil packs & massage oils.