The Coflex implant is not designed for the treatment of lower back pain. It is a device that sits between the spinous processes and induces flexion of the vertebra. Flexion of the spine will load the discs. If the back pain is generated from the discs (as it typically is), then this device will increase the load on the discs and increase lower back pain.
You have concerning weakness of both the L5 and the S1 motor groups (see section under “nerve injuries and recovery” on the website for further explanation. What you need is a back pain workup from a thorough spine surgeon who can also explain why you have weakness.
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.