Inversion tables are popular at-home devices that offer a non-surgical approach to alleviate back pain by using gravity to stretch the spine. This technique is often sought by individuals hoping to find relief from the discomfort associated with a herniated disc. A herniated disc occurs when the soft, inner material of a spinal cushion pushes out, pressing on nearby nerves. The central question is whether this gravitational pull is a benefit or a risk that could potentially worsen the underlying injury.
Anatomy of a Herniated Disc
The spine is structured with intervertebral discs that function as shock absorbers between the bony vertebrae. Each disc has a tough, fibrous outer ring (annulus fibrosus) encasing a softer, jelly-like center (nucleus pulposus). This highly hydrated internal material gives the disc its cushioning and flexibility.
A herniated disc happens when the nucleus pulposus pushes through a tear or weakness in the annulus fibrosus. The displaced material can then protrude into the spinal canal or the openings where nerves exit the spine. This protrusion often compresses an adjacent spinal nerve root, which is the source of radiating pain, numbness, and weakness experienced in the legs, commonly known as sciatica.
The Mechanics of Spinal Decompression
The function of an inversion table is to achieve spinal decompression through traction. By inverting the body, a user employs their own body weight and gravity to create a distraction force along the spinal column. This force gently pulls the vertebrae apart, temporarily increasing the space between them.
The goal of this increased intervertebral space is to relieve pressure on the spinal discs and nerves. Reducing the compressive load on a herniated disc is thought to encourage the displaced nucleus material to retract slightly, or at least alleviate nerve root irritation. This process can reduce muscle spasms and provide temporary relief from pain and stiffness.
Specific Scenarios for Worsening Symptoms
While the therapy is designed to help, an inversion table can make a herniated disc worse under specific conditions. Using the table during the acute, highly inflamed phase of an injury can be counterproductive, potentially increasing muscle guarding or spasm. If the disc tear is substantial, aggressive inversion may introduce additional trauma to the already compromised structure.
Improper use, such as inverting to too steep an angle or for excessive durations, can also lead to aggravation. Overly aggressive traction can place undue strain on the ligaments and muscles surrounding the spine. Most benefits occur at shallow angles, often between 30 and 60 degrees of recline, not full inversion.
The uniform gravitational pull of an inversion table is not targeted, unlike mechanical decompression machines used in a clinical setting. For certain types of severe disc protrusions or spinal instability, this generalized force may not achieve the desired centralization of the disc material. If a user tenses up or improperly positions themselves, the increased pressure may sometimes push the herniation further, making the symptoms worse.
Precautions and Alternative Treatments
Before attempting inversion therapy, consulting with a physician or physical therapist is necessary to ensure the treatment is appropriate for the specific nature of the herniated disc. It is advisable to begin with shallow angles, such as a 20- to 30-degree recline, for very short sessions lasting only a few minutes. Gradually increase duration and angle based on comfort and symptom response, allowing the body to adapt without causing reflexive muscle contraction.
Several pre-existing medical conditions are considered contraindications that forbid the use of inversion tables entirely. These include severe hypertension, glaucoma, heart disease, and retinal detachment, as the inverted position can significantly increase blood pressure and intracranial pressure. Individuals with known lumbar instability, like spondylolisthesis, should also avoid inversion therapy.
Alternative Treatments for Herniated Discs
For those who cannot use an inversion table or find it unhelpful, several alternative treatments exist for a herniated disc. Physical therapy, which focuses on core strengthening and flexibility exercises, is often the most recommended non-surgical approach to provide long-term stability. Other conservative options include manual therapy, anti-inflammatory medications, and epidural corticosteroid injections to manage pain and localized inflammation.