If you struggle with mechanical low back pain or lower back tightness due to a weak lumbar multifidus muscle, a new minimally invasive procedure that uses neurostimulation to reactive the muscle may help reduce or eliminate that pain.
Ongoing lower back pain and strain can cause your deep spinal muscle that supports your back, called the multifidus, to “shut off” or atrophy. This leads to spinal instability and further pain as other muscles try to compensate. Reactivating the multifidus is difficult, and physical therapy may not do the trick. In those cases, Neurosurgery One now offers an implantable neurostimulator that can help relieve mechanical chronic low back pain by reactivating the multifidus.
Unlike back pain caused by nerves (also called neuropathic pain), mechanical pain means it is caused by stress or damage to nonneural tissue such as joints, muscles, or ligaments. While pain from a pinched nerve might show up somewhere else, such as down the leg, mechanical pain hurts at the site of movement.
People with mechanical chronic low back pain may not get meaningful, lasting relief from physical therapy, medication, and other conservative pain management therapies. Rehabilitative neurostimulation provides rehabilitation to the underlying muscle dysfunction behind mechanical chronic low back pain.
FAQs About Multifidus Dysfunction and Rehabilitative Neurostimulation
Continue reading below to learn more about mechanical lower back pain caused by a weak multifidus muscle and how neurostimulation can treat it, or use one of these links to go directly to the Q&A that interests you.
- What is the role of the multifidus?
- How does a weak multifidus cause low back pain?
- How do you know if weak muscles are causing lower back pain?
- How is lower back pain due to multifidus dysfunction treated?
- How does ReActiv8 rehabilitative neurostimulation relieve lower back pain?
- Is ReActiv8 neurostimulation effective at treating low back pain?
- Who is a candidate for ReActiv8 neurostimulation to treat a weak multifidus?
- How can I be evaluated for multifidus neurostimulation?
What is the role of the multifidus?
The multifidus is a spinal muscle whose most important job is to stabilize the lumbar (low back) spine. Made up of a series of small, triangular muscle bundles on either side of the spine, the primary multifidus action is to extend the back when the muscles on both sides work together. When just one side contracts, the multifidus also contributes to side bending and rotation.
For years, the medical literature has reported a connection between a weak multifidus muscle and chronic low back pain. For example, a 2010 literature review in The American Academy of Physical Medicine and Rehabilitation concluded that:
- The multifidus has an important role in stabilizing the low back.
- Dysfunction of the multifidus is strongly associated with low back pain.
- Multifidus dysfunction tends to continue even after pain has resolved, likely contributing to the high recurrence rate of low back pain.
- An MRI is the best way to identify atrophy of the multifidus.
How does a weak multifidus cause low back pain?
When there is pain in a joint, including the facet joints between your spinal vertebrae, a reflex called arthrogenic muscle inhibition (AMI) can occur. AMI lowers the activity of the nerve cells that control the muscle that moves or stabilizes that joint. In the lower back, that stabilizing muscle is the multifidus.
When you experience low back pain or strain, AMI can shut off the multifidus. This leaves your spine with less structural support, forcing other muscles to compensate, which then triggers more lower back tightness and pain.
The longer the multifidus is inactive, the more weakness and atrophy develops in the muscle, making it difficult to recruit the multifidus through physical therapy.
How do you know if weak muscles are causing lower back pain?
If you are experiencing ongoing lower back pain that is not due to a diagnosed condition, such as a herniated disc, and physical therapy or pain medications haven’t helped, you should be evaluated for multifidus dysfunction.
At Neurosurgery One, our Denver neurosurgeons are experts at diagnosing mechanical lower back pain. To evaluate you for multifidus dysfunction, your spine surgeon will review your magnetic resonance imaging (MRI) scans and perform an exam that includes physical tests, such as the Prone Instability Test (PIT), to test for lumbar instability. If you have a current MRI, you do not need to get new imaging.
How is lower back pain due to multifidus dysfunction treated?
Mechanical lower back pain due to weak or atrophied lower back muscles is treated by re-engaging the muscle so that it can do its job in supporting the facet joints in the spine. Unfortunately, physical therapy often cannot reactivate the multifidus. In these cases, Neurosurgery One now offers rehabilitative neurostimulation called ReActiv8.
ReActiv8 is the first FDA-approved rehabilitative neurostimulation therapy to treat mechanical chronic low back pain. Implanted in your lower back in a minimally invasive procedure, ReActiv8 is a device that stimulates the nerves that control the multifidus.
How does ReActiv8 rehabilitative neurostimulation relieve lower back pain?
If you have been diagnosed with mechanical lower back pain due to multifidus dysfunction and you qualify for ReActiv8, your spine surgeon will implant the neurostimulation system in your lower back. The surgeon positions two very thin electrical leads to stimulate the nerves that control the multifidus muscle. The leads are connected to the implantable pulse generator, which is placed under the skin in your upper buttock or lower back. The procedure is minimally invasive, which means it is performed through tiny openings using special equipment to minimize the size of the incision and any disruption to muscles, tendons and organs. It is performed in an outpatient surgical setting, and you go home the same day.
Twice a day, you will use a wireless remote to start your therapy session, then lie down and relax. ReActiv8 generates painless electrical pulses that cause your multifidus muscle to contract and relax throughout the 30-minute session.
Over time, this stimulation helps “wake up” your multifidus so that it begins functioning again and stabilizing your lumbar spine. As this occurs, other muscles that were compensating can relax and your pain is reduced.
Is ReActiv8 neurostimulation effective at treating low back pain?
In a clinical trial of 204 participants, patients who were implanted with the ReActiv8 neurostimulator reported progressive long-term improvements in pain and function. The study was published in two peer-reviewed medical journals, Neuromodulation and Pain. It found that one year after receiving the neurostimulator:
- 78% of patients said they were “definitely satisfied” with the procedure
- 73% reported 50% or more reduction in pain and/or an improvement in disability
- 48% of patients on opioids before the procedure eliminated or reduced their intake
In a more recent three-year clinical trial, 83% of patients who were implanted with the ReActiv8 neurostimulator experienced substantial and clinically meaningful improvements in pain or disability, or both. The data was published in the journal of the International Neuromodulation Society, and analyzed 3-year data for 133, while two-year data were available for 156 patients and one-year data were obtained from 176 patients. Results showed:
- 77% of patients reported a reduction of pain intensity by 50% or more from baseline at three years (visual analogue scale [VAS] score), compared to 71% at two years and 64% at one year
- 71% of patients who were taking opioids at baseline voluntarily eliminated (49%) or reduced (22%) their opioid use at three years, compared to 60% at two years and 48% at one year
- 63% of patients reported a greater than 20-point reduction on the Oswestry Disability Index at three years, compared to 61% at two years and 57% at one year, and 67% of patients reported a VAS score <2.5 at three years, compared to 65% at two years and 52% at one year.
Please note: The clinical trials linked above and cited below were funded by Mainstay Medical, the manufacturer of ReActiv8, but the results were peer reviewed.
Deckers, Kristiaan et al. “New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial.” Neuromodulation : journal of the International Neuromodulation Society vol. 21,1 (2018): 48-55. doi:10.1111/ner.12741
Gilligan, Christophera et al. “An implantable restorative-neurostimulator for refractory mechanical chronic low back pain: a randomized sham-controlled clinical trial.” PAIN: October 2021 – Volume 162 – Issue 10 – p 2486-2498. doi:10.1097/j.pain.0000000000002258
Gilligan C, Volschenk W, Russo M, Green M, Gilmore C, Mehta V, Deckers K, De Smedt K, Latif U, Sayed D, Georgius P, Gentile J, Mitchell B, Langhorst M, Huygen F, Baranidharan G, Patel V, Mironer E, Ross E, Carayannopoulos A, Hayek S, Gulve A, Van Buyten JP, Tohmeh A, Fischgrund J, Lad S, Ahadian F, Deer T, Klemme W, Rauck R, Rathmell J, Schwab F, Maislin G, Heemels JP, Eldabe S. Three-Year Durability of Restorative Neurostimulation Effectiveness in Patients With Chronic Low Back Pain and Multifidus Muscle Dysfunction. Neuromodulation. 2022 Sep 26:S1094-7159(22)01254-5. doi: 10.1016/j.neurom.2022.08.457. Epub ahead of print. PMID: 36175320.
Who is a candidate for ReActiv8 neurostimulation to treat a weak multifidus?
Candidates for ReActiv8 neurostimulation are adults who:
- have experienced mechanical chronic low back pain on at least half the days in the past year
- failed conservative medical management, including physical therapy and medication (meaning these have brought only temporary or inadequate relief)
- had no prior lumbar spine surgery or clear indications for spine surgery
- have pain that is primarily in the low back and is greater than pain in the leg; if you have pain in the leg, it does not extend below the knee
How can I be evaluated for multifidus neurostimulation?
If you live in the Denver area and would like to find out if your lower back pain can be treated with ReActiv8 neurostimulation, we are currently assessing patients in our Lone Tree and Castle Rock medical offices and via telehealth for all Colorado residents.
You can request an evaluation by submitting the form below or calling Neurosurgery One at 720-638-7900, Option 4. Please let us know you are calling to schedule a ReActiv8 evaluation.
Our board-certified spine neurosurgeon will review your MRI, talk to you about your health history, and let you know if you are a good candidate for ReActiv8 neurostimulation or other procedures to treat chronic low back pain, including spinal cord stimulation, temporary external neurostimulation, or the Intracept procedure to treat vertobrogenic low back pain.