The following is an excerpt from Ilene' Smith's article published in Psych Central:
Why Somatic Experiencing Is Different: When trauma strikes, the nervous system loses its ability to maintain a state of balance. The trapped energy from the traumatic experience causes the nervous system to rush to a state of fight, flight, or freeze — the “over” or “underreaction” that we discussed earlier. SE works to help bring the nervous system back on line by helping the individual restore their sense of safety. This can only happen when the body has a “biological completion” and the trauma energy has the opportunity to reintegrate back into the body.
SE uses a clinical map to access the physiological states of survival known as fight, flight, and freeze and helps release the self-protective and defensive responses we hold in our body. When an event happens too fast and we do not have the time or ability for self-protection or defense, this survival energy gets stuck in our body as an incomplete biological reaction. This stuck energy is what causes trauma symptoms.
In this way, humans are no different than animals in the wild. When an animal has been under threat they will reset their nervous system by shaking off the trauma. This shaking is a “biological completion” for the animal that allows its nervous system to restore its sense of well-being.
Often in talk therapy, an individual continues to relive the story of the past experience. And while it is important for the story to be heard, the retelling of it alone does not enable the body to create a new and more empowered relationship with the past experience. SE is different. SE includes talking, but the talking is used to track body sensation and meaning attached to experiences, rather than bring the individual back into the event of the trauma. When we bring the body into the therapy process and facilitate a way for the individual to physically move through the experience with a sense of safety, the relationship to the experience changes and the stuck energy will discharge.