Serratus Posterior Inferior Muscle Pain

The serratus posterior inferior contributes to aching in the middle and lower back. The aching is felt at the bottom of the ribs and toward the outside of the back. Because of the location of the pain people often fear it is associated with the kidneys.

Contents Of Article:

Muscle Location

Trigger Point Symptoms 

Trigger Points Cause

Trigger Point Prevention

Trigger Point Treatment

Interesting Facts 

Other Contributors To Low Back Pain

Serratus Posterior Inferior Pain Pattern Serratus Posterior Inferior Pain Referral Pattern

Where Is The Serratus Posterior Inferior Located?

The muscle is located in the middle to lower back. It connects the lower 4 ribs to four vertebrae (T11, T12, L1, L2) in the middle and lower back.

What Movements Does The It Control?

  • Forced expiration (breathing out when breathing hard)
  • Assists with twisting at the waist
  • Assists with straightening the trunk (standing up straight)

Looking for detailed muscle anatomy? The Serratus Posterior Inferior Anatomy page has origin, insertion, innervation, and blood supply information. It also lists agonists and antagonists for each muscle action.

Serratus Posterior Inferior Origin, Insertion, Action, Innervation Serratus Posterior Inferior Muscle

What Are The Signs and Symptoms of Serratus Posterior Inferior Trigger Points?

Pain caused by trigger points in the SPI is centered around the TrP and does not radiate or refer to other areas of the body.

  • Pain in the lower back when stretching to reach overhead
  • Pain in the lower back when twisting at the waist
  • Pain in the lower back when bending over
  • Discomfort breathing, most noticeable when exhaling

Trigger points are small knots found in the muscle that when pressed increase pain in the area or send referred pain to another area of the body. To learn more about trigger points read Muscle Trigger Points and How They Contribute To Muscle and Joint Pain.

What Causes Trigger Points To Develop In The Serratus Posterior Superior Muscle?

  • Twisting the body when lifting
  • Overreaching overhead or to the side of the body
  • Lifting something heavy using the back muscles instead of leg muscles
  • Sleeping on a sagging or too soft mattress

Reaching overhead stresses the serratus posterior inferior.

How To Avoid Development of Trigger Points

  • If you have a job or activity that requires you repeatedly reach overhead, try using a step ladder so you are not stressing the muscle.
  • When lifting do not bend over and then lift. Squat down and bend the knees keeping your back straight and use your legs as the power source to pick up the item. Also, do not use a twisting motion at the waist while lifting. Secure the item, then turn the body before taking a step.
  •  Sleeping on a lumpy or too soft mattress will cause soreness, stiffness, and the development of trigger points.  Consider replacing your mattress.


A lumpy or too soft mattress wreaks havoc on the body. It can cause pain throughout the body and is especially hard on the lower back.

I have two mattresses that I recommend. The first is the Casper Sleep Essential which is on my bed. This mattress is firm but has enough softness to provide support. I have had this mattress for 3 years and highly recommend it to those who like a firm but not hard mattress. 

The Snuggle-Pedic Mattress is a mattress I have slept on several times and I can recommend it. It is not as firm as the Casper, but provides needed support. Recommended for those who need support but prefer a softer feel.

Serratus Posterior Inferior Trigger Point Treatment

One of the first steps to reducing and eliminating pain is to check for and deactivate any trigger points in the muscle. You can find a massage therapist, physical therapist, or a chiropractor trained in trigger point therapy to show you how to find and self-treat the TrP. Not everyone has the specific training so be sure and ask before making an appointment.

Another option is to use The Trigger Point Therapy Workbook to learn self-treatment. The book explains trigger points thoroughly and includes diagrams to show the location of the trigger point and how to treat it. I highly recommend this book to everyone who is interested in learning about and how to reduce muscle pain throughout the body.

If you plan to use the workbook you will need to buy a tool to apply the treatment to hard to reach muscles which include the serratus posterior inferior. I recommend the Thera Cane Massager. The cane has knobs on which are perfect for TrP treatment and the cane shape makes it easy to treat those hard to reach places.

Another option is to use small hard balls like The Kieba Massage Lacrosse Balls. You use the balls by placing the ball between your back and wall rolling the ball up and down or across the area. The balls work well for treatment however require that you have good balance as well as good motor control which is why I prefer the Thera Cane.

To help with pain and stiffness you can use a pain-relieving cream. For the serratus posterior inferior, I recommend Sombra Warming Gel. Sombra gently heats the area relieving pain and stiffness to get you through the day.

Another option I recommend is Biofreeze Professional Gel. Biofreeze cools the area somewhat like ice. It is what I recommend for all soft tissue issues that are inflamed and have swelling. It is also excellent for pain relief.

The best resource to learn how to treat small painful knots is The Trigger Point Therapy Workbook. The authors explain trigger points and their effects in everyday language, not medical speak. I recommend this book to anyone interested in learning to treat their own muscle pain.

The Thera Cane was developed to allow you to treat muscles that you cannot reach easily like muscles in the back, hip, and feet. This is my tool of choice for treating TrPs in the serratus posterior muscles. 

If you are buying the Trigger Point Workbook to self-treat the biceps femoris you will need a hardball for treatment. The Kieba Massage Lacrosse Balls are a good choice to use on the thighs and other areas throughout the body.

How Long Before I Feel A Reduction In Pain?

Trigger points respond best to several 1-2 minute treatments throughout the day. A reduction of pain and tightness is noticeable after a few treatments.

It is important to be consistent with your treatments and continue treatment until the Trp is deactivated.

If you have chronic low back pain the Professional’s Choice Back Brace will help reduce your pain and stiffness. The waist wrap and 2 side straps are easily adjusted and provide support compression to the low back and abdomen. It is the only low back brace I recommend because it works!

Interesting facts about the serratus posterior inferior muscle:

  • The serratus posterior inferior is one of the muscles that is achy and stiff when you have slept on a mattress that is too soft.
  • It is the muscle that cramps when you stretch too far when trying to reach something overhead
  • If the serratus muscles are tight, they can contribute to breathing difficulty

Serratus posterior inferior muscle pain and symptoms can be similar to, contribute to, and be affected by these medical diagnoses:

  • Rib Subluxation/Dislocation
  • Slipping rib syndrome
  • Costochondritis
  • Sprain/Strain syndrome of the mid-back
  • Thoracic Spine Hyperkyphosis
  • T10 T11 or T12 radiculopathy
  • Scoliosis
  • Kidney Stones
  • Kidney Infection
  • Ankylosing Spondylitis

Sombra Warm Therapy Gel is recommended for relaxing muscles and relieving pain. It warms without the burning heat of other gels. An excellent choice for pain caused by trigger points, muscle/joint over-use and stiffness, and arthritis. (Not sold in stores)

Biofreeze Pain Relieving Gel cools the area much like ice discouraging inflammation. It provides excellent pain relief between cold treatments. Recommended by medical professionals and trainers.

Other muscles that should be considered and examined:

Check for satellite trigger points in these muscles:

If you find trigger points in the biceps femoris it is likely you will find trigger points in some or all of these muscles:

  • Iliocostalis
  • Longissimus thoracis
  • Trapezius
  • Serratus posterior superior
  • Latissimus dorsi
  • Scalenes

Low Back Pain? Other Muscles You Should Consider:

Quadratus Lumborum contributes to pain in the lower back and hips.

Iliopsoas muscles contribute to pain in the lower back, abdomen, and groin.

Iliocostalis Thoracis contributes to pain in the lower back, low abdomen, and upper back.

Longissimus Thoracis contributes to pain in the lower back, hip, and buttocks.


Donna Martin

Massage Therapist Owner: Twelve years of experience working with clients with chronic pain, post injury pain, and post surgery pain. Muscle dysfunction is often overlooked but can hold the key to many pain conditions.

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