Vertebral axial decompression (also described as motorized spinal traction or non‑surgical spinal decompression) is a computer‑driven traction technique in which a patient lies on a specialized table with a pelvic harness while the table incrementally applies and relieves distraction forces to the lumbar or cervical spine to produce controlled decompression. The device cycles through gradual increases to a target tension and then decreases the force; the number and frequency of sessions vary by treatment protocol and device [[5]].
The clinical literature consists of multiple small randomized controlled trials (RCTs), retrospective series, systematic reviews, and meta‑analyses that report inconsistent results and are generally limited by methodological weaknesses. Common limitations across studies include small sample sizes, incomplete reporting and dropout data, short‑term follow‑up with little or no assessment after therapy cessation, heterogeneous interventions and outcome measures, lack of sham or no‑treatment controls in many trials, and risk of bias related to inability to blind participants to a mechanical traction intervention. Systematic reviews and recent evidence assessments conclude that available RCT data are low‑ to very low‑quality and provide at best short‑term and inconsistent improvements in pain or function, with uncertainty about clinical meaningfulness and long‑term benefit [[6],[9],[14],[17]].
Major clinical practice guidelines do not support routine use of traction or vertebral axial decompression for neck or low back disorders. The American College of Physicians (ACP) states that evidence is insufficient to determine the effectiveness of traction for acute, subacute, or chronic low back pain. The North American Spine Society (NASS) similarly considers the evidence insufficient to recommend traction for subacute or chronic low back pain and for certain subgroups such as lumbar disc herniation with radiculopathy or degenerative lumbar spinal stenosis. Taken together, guideline statements and the weight of published reviews support the conclusion that motorized spinal traction is unproven and not medically necessary for routine management of neck or low back pain [[25],[26],[6]].
UnitedHealthcare’s policy reflects these findings: motorized spinal traction devices are considered unproven and not medically necessary for treating neck and low back disorders due to insufficient evidence of efficacy. The policy was updated effective May 1, 2026 to refresh the clinical evidence and references while maintaining the same coverage stance [[3],[31]].