If you are hurt (1) ...

... Look  ABOVE.

Unfortunately, where you are hurt might not be where the issue is. Compensation, imbalance results of an actual tightness or injury might trigger the pain, but might not be the root cause.

Typically, if your knee hurt, it is likely because you IT Band is tight, or your quads.
If you have Achilles tendinitis, look at your calf.

Tendons, Joints are usually symptoms of muscle and motion imbalance.

Go on the web, and look for PT rehabilitation exercises.

Don't R.I.C.E. It is proven ineffective. (At least when the pain is no more acute).

R.I.C.E. has been cancelled.

Move it.

Stretch it.

Massage it.

Yoga it.

Muscle and Joint Home-made massage magic lotion.(Yothera)
Not a partial opinion by any mean.

I am still working on my big toe, Turf Toe ?, nowadays, and I have seen good improvement lately.

(I was immobilized after the Honolulu Marathon for two weeks because of it.)

The key point is to favor the blood flow. Blood, oxygen is the key for a quick recovery.

Move it.

Stretch it.

Massage it.

Yoga it.