A muscle that helps stabilize and extend the lumbar spine
By Anne Asher, CPT
Medically reviewed by Mohamad Hassan, PT
Fact checked by Sarah Scott
The multifidus muscle is a series of long, narrow muscles located on either side of the spinal column that help stabilize the lower portion of the spine, called the lumbar spine.1 It's also referred to as the lumbar multifidus.
The multifidus muscle plays a role in extending your back and helps keep your spine stable. Weak or atrophied multifidus muscles can cause back pain.2
This article reviews the anatomy and function of the multifidus muscle. You will also learn what causes lower back pain and how to strengthen your lumbar multifidus with a couple of simple exercises you can do at home or in a gym.
SEBASTIAN KAULITZKI / SCIENCE PHOTO LIBRARY / Getty Images
Lumbar Multifidus Anatomy
The multifidus muscle is the innermost layer of three layers of muscles of the back, known as the deep layer.
The deep layer is tasked with the movement of the spine. The other two, known as the intrinsic and superficial layers, are responsible for the movement of the thoracic cage (rib cage) and shoulders, respectively.3
The multifidus muscle is a long, narrow muscle that runs down both sides of the spine and has several attachment points:
The thoracic spine of the middle back
The lumbar spine of the lower back
The iliac spine at the base of the wing-shape iliac bone of the pelvis
The sacrum (the series of bones at the base of the spine connected to the tailbone)
The multifidus muscle works together with the transversus abdominus muscle of the stomach and pelvic floor muscles of the pelvis to stabilize the lumbar spine while standing or moving.4
Multifidus Muscle Function
The main function of the multifidus muscle is to stabilize the lumbar spine, but it also helps extend the lower spine whenever reaching or stretching.5
Because the multifidus muscle has numerous attachment points and is serviced by a specific branch of nerves called the posterior rami, it allows each spinal bone (vertebra) to work individually and more efficiently. This, in turn, helps protect against spinal deterioration and the onset of arthritis.6
The multifidus muscle works alongside two other deep muscle groups to stabilize and move the spine in complex ways:6
The rotatores muscle situated on each side of the spine enables unilateral rotation (turning from side to side) and bilateral extension (bending backward and forward) of the spine.
The semispinalis muscle situated on each side of the spine above the multifidus muscle allows you to extend and rotate the head, neck, and upper back.
Depending on how you want to move, these muscles can move in the same direction (such as twisting the body in one direction), in opposite directions (such as turning the hips one way and the shoulders the other way), or in complex ways (such as extending the back while twisting and bending).
The multifidus muscle helps ensure spinal strength because it has more attachment points to the spine than either the intrinsic or superficial layer. This reduces spinal flexibility and rotation but increases strength and stability.3
At the same time, the multifidus muscle "co-contracts" with the transversus abdominus, providing stability around the entire torso, including the abdomen and lower back.6
Cause of Lower Back Pain
Because the multifidus muscle is tasked with lower spine stability, a weak multifidus muscle destabilizes the spine and provides less support to the individual vertebra. This puts pressure on muscles and connective tissues between and adjacent to the spinal column, increasing the risk of lower back pain.2
Over time, the loss of muscle strength and stability can cause the muscle to atrophy, or waste away. This, in turn, can cause the compression of the vertebra and a plethora of other back-related problems.7
Back problems associated with multifidus muscle deterioration include:2
Herniated discs (also known as bulging discs or slipped discs)
Nerve entrapment or compression ("pinched nerve")
Referred pain (nerve pain emanating from the spine felt on other parts of the body)
Osteoarthritis ("wear-and-tear arthritis")
Spinal osteophytes (bone spurs)
If you also have weak abdominal muscles or weak pelvic floor muscles, your entire core might be compromised and further increase the risk of lower back pain and injury.
How to Strengthen Your Multifidus Muscle
The multifidus muscle comprises part of your core muscle group. This not only includes the muscles of your back but also your abdominal muscles and oblique muscles on each side of your body (which help stabilize the trunk and twist it from side to side).
By strengthening these core muscles, you are strengthening the multifidus muscle as well.
With that said, there are exercises that target the lumbar muscles directly. These include lifts that directly engage the lower back muscles and extensions that activate and contract them.8
Here are two examples that directly engage the multifidus muscle:
One-Arm Row
This is a common exercise done at home or in a gym that requires a dumbbell and a bench.
To do a one-arm row:
Place your right knee and right hand on the bench so that your torso is parallel to the floor.
Place a dumbbell on the floor beneath your left hand and grab it.
Lift the dumbbell smoothly, avoiding jerking, until the back of your arm is parallel to the floor. Hold for a second or two.
Lower the dumbbell steadily.
Repeat for a total of eight to 12 reps, breathing in as you lift and exhaling as you lower the weight.
Switch sides and repeat.
Rest and repeat steps 1 through 6 for a total of three sets.
The Bird Dog
This is an exercise you can perform at home with no weights.
To do the bird dog:
Get on all fours on the floor.
Ensure your hands are positioned directly under your shoulders and your knees are positioned directly underneath your hip in a 90-degree angle.
Slowly lift your right arm and left leg, extending them fully until they are parallel to the floor. (This may take practice as you will likely feel unsteady at first.)
Stretch your arm and leg fully to get a complete extension. Hold for several seconds.
Lower your leg and arm.
Repeat steps 1 through 6, but this time with the left arm and right leg.
Alternating sides for one set of eight to 12 reps.
Rest and repeat for two more sets.
There are other exercises that specifically target the multifidus muscle, some of which you can do at home and others which require a gym. For advice and instructions, speak with your healthcare provider, a physical therapist, or a personal trainer.
Summary
The multifidus muscle is situated on both sides of the lumbar spine and provides stability and strength to the lower back. Any weakness of the multifidus muscle can lead to spinal instability, vertebral compression, and back pain.
Exercise targeting the multifidus muscle and other core muscles can help prevent back pain and protect against arthritis and other problems affecting the lower back.
The multifidus muscle may not be all the large, but it is critical to the health and stability of your lower back. While it is important to keep your lower back strong with routine exercise, you need to avoid training too aggressively as this could cause back strain and injury.
Always start slowly with back exercises, adding weight and repetitions gradually. If you can't do eight reps, just do six and go for seven next week. Be sure to maintain good form, neither overarching the back nor using jerking movements when lifting a weight.
You should also consider speaking with a physical therapist or personal trainer who can help you build the appropriate core training program based on your age and physical limitations.
Sources
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2.Hodges PW, Danneels L. Changes in structure and function of the back muscles in low back pain: different time points, observations, and mechanisms. J Orthop Sports Phys Ther. 2019;49(6):464-76. doi:10.2519/jospt.2019.8827
3.Agten A, Stevens S, Vertbrugghe V. The lumbar multifidus is characterised by larger type I muscle fibres compared to the erector spinae. Anat Cell Biol. 2020 Jun 30;53(2):143–50. doi:10.5115/acb.20.009
4.Lynders C. The critical role of development of the transversus abdominis in the prevention and treatment of low back pain. HSS J. 2019;15(3):214-20. doi:10.1007/s11420-019-09717-8
5.Padwal J, Berry DB, Hubbard JC, et al. Regional differences between superficial and deep lumbar multifidus in patients with chronic lumbar spine pathology. BMC Musculoskelet Disord. 2020;21(1):764. doi:10.1186/s12891-020-03791-4
6.Hebert JJ, Koppenhaver SL, Teyhen DS, Walker BF, Fritz JM. The evaluation of lumbar multifidus muscle function via palpation: reliability and validity of a new clinical test. Spine J. 2015 Jun 1;15(6):1196–202. doi:10.1016/j.spinee.2013.08.056
7.Hodges PW, James G, Blomster L, et al. Multifidus muscle changes after back injury are characterized by structural remodeling of muscle, adipose and connective tissue, but not muscle atrophy: molecular and morphological evidence. Spine (Phila). 2015;40(14):1057-71. doi:10.1097/BRS.0000000000000972
8.Pillastrini P, Ferrari S, Rattin S, Cupello A, Villafañe JH, Vanti C. Exercise and tropism of the multifidus muscle in low back pain: a short review. J Phys Ther Sci. 2015;27(3):943-945. doi:10.1589/jpts.27.943
9.Woodham M, Woodham A, Skeate JG, Freeman M. Long-term lumbar multifidus muscle atrophy changes documented with magnetic resonance imaging: a case series. J Radiol Case Rep. 2014 May;8(5):27–34. doi:10.3941/jrcr.v8i5.1401
By Anne Asher, CPT
Anne Asher, ACE-certified personal trainer, health coach, and orthopedic exercise specialist, is a back and neck pain expert.
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