The theory behind somatic psychotherapy is the understanding that there is complex interdependent relationship between the body and the mind with regards psychological trauma. Recent neuroscience supports this understanding and I frequently reference the work of Bessel van der Kolk, Peter Levine, Pat Ogden and others who I have been fortunate to do some professional development work with.
In terms of what this looks like in session it might involve learning to become more aware and tolerant of bodily sensations, breath and voice work, physical movement (even boxing), healing touch and TRE (Trauma Release Exercises). Throwing balls, beanbags, and punches are all fairly normal parts of therapy with me!