"The best option would be a physiotherapist. They will be able to massage the knots out - but even an inexpert massage will help. To massage it out, locate the knot on your back. It will be a small ball about the size of your thumb. Circle the knot firmly - it should be slightly painful to the person. Work each knot for a minute, then move on. Do each knot over twice.
Swimming is also good exercise for the condition as it "works" these muscles. Also try heat pads to lessen tightness in the muscles. And a cream like Voltaren will reduce swelling. It should take about a week to make a noticible difference if the knots are bad and about 4 weeks to completely disappear.To stop the knots reoccurring or getting worse, examine your lifestyle for the cause of the knots. Is it the position you sleep in? Is it stress? Is it the way you sit at work?"