I have never seen 3-4 thoracic nerve roots injured all in a row without a cord injury but I guess anything is possible. I would highly suspect that there might be something else going on with the abdominal wall such as direct trauma to the muscle.
Do not be too impatient with this. Give it some time and you might be surprised by the results.
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.