Best way to get a knot out of my arm?

A knot: is a persistent muscle spasm...the muscle stays contracted. You can treat it yourself with stretching, massage, application of heat or cold, acupressure. If this doesn't do the trick, you may need to see a massage or physical therapist. In addition to targeted massage, physical therapists may apply ultrasound or electrical stimulation to relax the muscle. Good luck:)