The Emotion Code is a well-known book by Bradley Nelson, DC.  He's a chiropractor who has developed a simple way of Releasing trapped negative emotions.  Releasing trapped negative emotions can be a powerful and healing process.  This can be done solo by an individual themselves but I find is more helpful and effective when done with a practitioner who is certified in this practice.  The book details several ways of testing individuals and releasing this emotional stress.  

We often don't completely resolve negative emotions because they are too painful or remind us of past painful events or we get distracted by our stressful modern lives.  We never get to truly cycle through our grief, anger, or disappointment.  Identifying specific acupuncture meridians and their correlated negative emotions with observable changes in range-of-motion, posture, and muscle strength can be helpful in cornering these pesky, hidden stressors and releasing them from the meridian or organ system so the body can heal and recover.  

This is not talk therapy (which I highly recommend with a qualified psychotherapist) it is a way of diagnosing when we feel in a certain negative fashion that our bodies will change in predictable, yet correctable, way.  This technique is often used as a part of a regular treatment session.  It may also be the focus of an extended session if it is that important to the patient.  I've used many other emotional kinesiology therapies like NET, EFT, and TFT.  I am a certified Emotion Code practitioner and have found this technique to be the most simple and efficient way of dealing with hidden emotional baggage that we all as human beings deal with.  Be prepared to be surprised!