Hey Readers! I am so glad you are here! It's time to talk about our butts! Haha! But, seriously, I have spent many, many, many hours researching the topic of “gluteal amnesia,” and I am so excited to share this knowledge with you all. This information has been game-changing for me and my fitness pursuits, and it has really opened my eyes to the importance of actively working my gluteal muscles throughout the day, everyday.
The information will be presented weekly in a 5-part series. In this 5-part series, I will go over:
What the “glutes” do and where they are located (part I)
What gluteal amnesia is and the implications of it (part II)
The muscular biology of gluteal amnesia (part III)
The neurobiology of gluteal amnesia (part IV)
Exercises and lifestyle activities that may help to prevent gluteal amnesia (part V)
Before we start diving deeper into the literature, I want to take a moment to briefly explain what gluteal amnesia is. Gluteal amnesia is a term coined by Dr. Stuart McGill, who is known for his many research articles and studies on back pain and how to treat it. Gluteal amnesia is a condition in which your gluteal muscles receive reduced input and activation from your nervous system based on a variety of reasons and causes (to be discussed over the course of this series). Essentially, your gluteal muscles “forget” how to activate fully, causing dysfunctional movement in the body. Gluteal amnesia goes by many names in the literature, including: dead butt syndrome, sleepy glutes, gluteal inhibition, gluteus maximus dysfunction, altered reciprocal inhibition of the glutes, and many others. Throughout this series, I will primarily use the term “gluteal amnesia.”
The “glutes,” also referred to as the “glute complex,” really consists of three muscles located on the posterior (or back) and lateral side of your hips – the gluteus maximus, gluteus medius, and gluteus minimus. The glutes are believed to have played a crucial role in the evolution of bipedalism (i.e. walking on two legs) in humans, ultimately allowing humans to use their upper extremities (i.e. arms, hands) in functional activities, such as lifting and gathering. These activities are largely unavailable to quadrupeds (i.e. animals walking on four legs). The glutes are highly important muscles in the human body, and they are responsible for your ability to stand upright, walk, run, jump, and many other movements. The problem is that in our modern society we tend to live very sedentary lives, so our glutes become chronically weakened over time. This causes a whole host of issues in the human movement system, including injury and pain, especially in hips, low back, knees, and even ankles.
So, what do the glutes actually do? Well, keep on reading to learn more about your super awesome butt muscles! Because, who doesn't want to learn more about their fannies?
Hip Movements Created by the Glutes
Movement in the body occurs at joints (for more information on movement and joint mobility click here), which is the location where two bones meet. Skeletal muscle contraction causes movement to occur at a joint (click here to read more about this process). Since this series is focused on the gluteal muscles, the main joint we are concerned with is the hip joint (aka coxal joint) – i.e. where the head of the femur (i.e. thigh bone) meets the pubic bone of the pelvis. The pelvis technically consists of three bones fused together - the ilium, the ischium, and the pubis, where the pubis is the more inferior (or lower) part of the pelvis.
Sometimes the gluteal muscles have the same function, and other times the gluteal muscles perform different actions from each other. The gluteal muscles, in general, are involved in someway with every movement in the hip joint, either primarily (i.e. they are the main muscle creating movement) or synergistically (i.e. they assist, or help, other main muscles for a movement). The main movements allowed at the hip joint include:
Flexion
Extension
Internal Rotation
External Rotation
Abduction
Adduction
Now, the gluteal muscles are not the only muscles that cause these hip movements. There are many other muscles that are located in, or near, the lumbo-pelvic-hip complex (LPHC) that also work to create these hip movements (as the pictures below illustrate). As stated above, sometimes the glute muscles are the primary movers, and other times they act as synergists to create these hip movements. Keep on reading for more detailed information on these hip actions.
Hip flexion. In hip flexion, the anterior (or front) side of the femur moves closer to the pubic bone of the hip. That is, the angle between the anterior femur and hip bone gets smaller. You move into hip flexion when you sit, walk, climb stairs, or bend down to reach the floor.
Hip extension. In hip extension, the anterior side of the femur moves further away from the pubic bone of the hip. That is, the angle between the anterior femur and the pubic bone of the hip increases. You move into hip extension when you step one leg behind you (as in walking) or when you stand up from sitting or bending over.
Hip internal rotation (aka medial rotation). In hip internal rotation, the head of the femur rotates inward, toward the middle of the body. You move into hip internal rotation when you cross one leg over the other.
Hip external rotation (aka lateral rotation). In hip external rotation, the head of the femur rotates outward, away from the middle of the body. You move into hip external rotation when stepping over obstacles on the ground or when opening your lifted knee out wide for tree pose in yoga.
Hip Abduction. In hip abduction, the head of the femur moves laterally (i.e. to the side), away from the midline of the body. You move into hip abduction when getting into, and out of, your car, or when jumping your feet wide apart during a jumping jack.
Hip Adduction. In hip adduction, the head of the femur moves medially, toward the midline of the body. You move into hip adduction when jumping your feet back together in a jumping jack. We also spend quite a lot of time in hip adduction when we are standing or sitting. In fact, your adductor muscles are prone to becoming overactive since we spend so much time in hip adduction during the day (but that is a topic for another blog post!).
What is Each Gluteal Muscle Responsible For?
Now that I have BUTTered you up with ALL things hip joint, let's get talk about the glutes themselves. The "glutes" consist of three muscles, on both your left and right sides, that can work together or in isolation to create various movements at the ipsilateral (i.e. same side) hip. Let's take a deeper look at each gluteal muscle and their individual functions at the hip joint.
Gluteus Maximus
The Gluteus Maximus (GMax) is the strongest and largest muscle in the body. It is the most superficial (i.e. closer to the skin) of the gluteal muscles. It originates at the sacrum (base of the spine) and inserts into the iliotibial tract (IT tract, a connective tissue tract on the lateral side of the thigh) and the top of the femur bone.
All the fibers of the GMax, working together, are responsible for creating:
Hip extension
External rotation of the hip
Abduction of the hip
The lower fibers of the GMax are responsible for:
Adduction of the hip
Gluteus Medius
The Gluteus Medius (GMed) is located on the lateral side of the hip. It is also a superficial muscle, except for the posterior (or back) portion, which is deep to, or below, the GMax. The GMed originates just below the top of the hip bone and inserts into the top of the femur.
All of the fibers of the GMed, working together, are responsible for:
Abducting the hip
The anterior (front) fibers are responsible for:
Flexing the hip
Internally rotating the hip
The posterior (back) fibers of the GMed are responsible for:
Hip extension
External rotation of the hip
Gluteus Minimus
The Gluteus Minimus (GMin) is deep to the GMed. The GMin originates at the top of the hip bones and inserts onto the top of the femur bone, similar to the GMed.
The GMin is responsible for:
Hip flexion
Hip abduction
Internal rotation of the hip
Working Together
All three glute muscles work together to provide stability to the lumbo-pelvic hip complex (LPHC) during functional movements, such as standing, walking, or balancing on one leg.
Summary
Whew! That was some FANNIEtastic info about our hip joints and glutes. The three gluteal muscles are located in the buttocks region, on the back and upperside of the hips. They are responsible for creating much of the movement that occurs at the hip joint, either agonistically (i.e. they are the main muscle that creates the motive power) or synergistically (i.e. they assist other agonists, or prime movers). The gluteals are highly important muscles, involved in standing upright, walking, climbing stairs, getting in/out of cars, and much more. Gluteal amnesia is a condition where the gluteal muscles have reduced neural activation, causing faulty movement patterns, and potential injury. In part II of this series, I will take a deeper look at gluteal amnesia (what it is and the implications of it).
Please note, the information presented in this blog series is not meant to diagnose gluteal amnesia or treat active cases of gluteal amnesia. After reading this series, if you have concerns about your gluteal muscles, please follow up with your physician, physical therapist, or sports medicine doctor. If you have been diagnosed with gluteal amnesia, please continue to heed the advice of the medical professional that evaluated you. Also, please keep in mind that I have simplified some anatomical and biological information (e.g. muscle attachment sites), so I can keep the focus on gluteal amnesia as best I can. If you feel like you need more thorough descriptions and explanations, please refer to my reference list at the end of each installment in this series. Also, a special thanks to my amazing husband for doing all of the artwork for this post. Matt - you truly are a very talented artist.
As always, the information presented in this blog post is derived from my own study of neuroscience, human movement, anatomy, and yoga. If you have specific questions about your gluteal muscles, please consult with your physician, physical therapist, or private yoga teacher. If you are interested in private yoga sessions with me, Jackie, you can book services on my website ("Book Online" from the menu at the top of the page), or you can email me at info@lotusyogisbyjackie.com for more information about my services. Also, please subscribe to my website so you can receive my weekly newsletters (scroll to the bottom of the page where you can submit your email address). This will help keep you "in-the-know" about my latest blog releases and other helpful yoga and wellness information. Thanks for reading!
~Namaste, Jackie Allen, M.S., M.Ed., CCC-SLP, RYT-200, RCYT, NASM-CPT
References:
Amabile, A.H., Bolte, J.H., & Richter, S.D. (2017). Atrophy of gluteus maximus among women with a history of chronic low back pain. PLOS One. p. 1 – 12.
Banaldo, P. & Sandri, M. (2013). Cellular and molecular mechanisms of muscle atrophy. Disease Models & Mechanisms. 6: 25 – 39.
Bento, J. (n.d.). Glute Training for Real-Life Strength. Breaking Muscle. Available here.
Biel, A. (2014). Trail Guide to the Body: A hands-on guide to locating muscles, bones, and more – 5th Edition. Books of Discovery. Boulder, CO.
Buckthorpe, M., Stride, M., & Della Villa, F. (2019). Assessing and treating gluteus maximus weakness – a clinical commentary. The International Journal of Sports Physical Therapy. 14(4): 655 – 669.
Clark, M.A. et al. (2018). NASM Essentials of Personal Fitness Training. 6th Edition. Jones & Bartlett Learning. Burlington, MA.
Freeman, S., Mascia, A., & McGill, S. (2013). Arthrogenic neuromusculature inhibition: A foundational investigation of existence in the hip joint. Clinical Biomechanics. 28: 171 – 177.
Gabriel, C. (2019). If You Sit at a Desk all Day, This Muscle Might be in Danger. Ortho Carolina. Available here.
Gordon, T., & English, A.W. (2016). Strategies to promote peripheral nerve regeneration: electrical stimulation and/or exercise. European Journal of Neuroscience. 43(3): 336 – 350.
James, J. (2017). Gluteal Amnesia. Back Forever. Available here.
Marieb, E.N. (2004). Human Anatomy & Physiology – 6th Edition. Pearson Education, Inc. San Francisco, CA.
Messi, M.L., et al. (2016). Resistance Training Enhances Skeletal Muscle Innervation Without Modifying the Number of Satellite Cells or their Myofiber Association in Obese Older Adults. Journals of Gerontology: Biological Sciences. 71(10): 1273 – 1280.
Muller, P., et al. (2020). Lactate and BDNF: Key Mediators of Exercise Induced Neuroplasticity? Journal of Clinical Medicine. 9(1136): 1 – 15.
Natarajan, A., Sethumadhavan, A., & Krishnan, U.M. (2019). Toward Building the Neuromuscular Junction: In Vitro Models to Study Synaptogenesis and Neurodegeneration. ACS Omega. 4: 12969 – 12977.
Neto, W.K., et al. (2020). Gluteus Maximus Activation during Common Strength and Hypertrophy Exercises: A Systematic Review. Journal of Sports Science and Medicine. 19: 195 – 203.
Roland, J. (2019). All About Gluteal Amnesia (‘Dead Butt Syndrome’). Healthline. Available here.
Schiaffino, S., et al. (2013). Mechanisms regulating skeletal muscle growth and atrophy. FEBS Journal. 280: 4294 – 4314.
Shors, T.J., et al. (2012). Use it or lose it: How neurogenesis keeps the brain fit for learning. Behavioral Brain Research. 227(2): 450 – 458.
Sonenblum, S.E., et al. (2020). Seated buttocks anatomy and its impact on biomechanical risk. Journal of Tissue Viability. 29: 69 – 75.
Stastny, P. et al. (2016). Strengthening the Gluteus Medius Using Various Bodyweight and Resistance Exercises. Strength and Conditioning Journal. 38(3): 91 – 101.
Theilen, N.T., Kunkel, G.H., & Tyagi, S.C. (2017). The Role of Exercise and TFAM in Preventing Skeletal Muscle Atrophy. Journal of Cell Physiology. 232(9): 2348 – 2358.
Wisdom, K.M., Delp, S.L., & Kuhl, E. (2015). Use it or lose it: Multiscale skeletal muscle adaptation to mechanical stimuli. Biomechanics and Modeling in Mechanobiology. 14(2): 195 – 215.
Yoo, W. (2016). Effects of bridging plus exercises with heel lift on lower extremity muscles. The Journal of Physical Therapy Science. 28: 1582 – 1583.