If you’re serious about butt-building, then you’ll need to have a good grasp on the muscles that actually power your butt.
In this ‘Buttocks Anatomy 101’ lesson, you’ll learn about the main aspects of the body which form the overall shape of your buttocks, and why this can help you in your better butt quest – from improving your workout effectiveness, to helping customize the shape of your butt.
Why You Should Know Your Butt
While it’s not exactly a glamorous topic, understanding the anatomy of your buttocks is essential if you are wanting to try and make changes to the appearance of your butt naturally.
Knowing what exactly gives rise to the shape of your butt will help you target the areas you’re not happy with. Also, since some aspects of buttocks shape are un-changeable (like your bone structure), you’ll be more aware of what you can and can’t change about your butt shape.
Learning about the different gluteal muscles can also help improve the effectiveness of your workouts. By visualizing the different muscles contracting while you perform exercises, you can get more muscle activation for a more effective workout – it is possible to even gain strength in muscles from purely imagined exercise! [1,2]
Basic Buttocks Structure

A great pair of human buttocks are pretty nice to look at, but let’s take a look at what makes them look like they do!
Male and female butts can vary a little in appearance due to differences in the sexes.
There are four main aspects that form the appearance of your butt:
- Bone Structure
- Muscles
- Subcutaneous Fat
- Skin
Let’s take a look at each of these in turn.
Bone Structure
The pelvis is the part of your skeleton which forms the shape of your hips and basis for your buttocks. This is one part of your butt that you cannot change.
Females typically have a wider pelvis than males to allow for childbirth and this causes the femur or thigh bones to also be positioned wider. The result is a wider-shaped butt associated with femininity:
Having a wider pelvis at the top (meaning your hip bones stick out a little more), or a pelvis that sits quite high, is one cause of a ‘H-shaped’ butt in women.
Males have a taller and narrower pelvis – leading to a squarer butt shape:
Buttocks Muscles
Muscles, along with fat, make up the main bulk and shape of the buttocks. There are many muscles in the buttocks region, but the main ones that contribute to the shape of the buttocks are;
-
- Gluteus Maximus
- Gluteus Medius
- Gluteus Minimus

Understanding where and how to activate these muscles is important if you want to influence the shape of your buttocks.
Muscle can be trained through exercise to become bigger. Since the superficial gluteal muscles are close to the outer layer of skin, changes in the size of these muscles will be visible beneath the skin.
Unfortunately, the glutes are a funny muscle group – while they are incredibly powerful, they also can be extremely lazy. Many people have inactive glutes, where their muscles simply have forgotten how to function correctly. Guess what this leads to? A flat butt, and posture problems.
Learning where these muscles are and how to activate them can restore glute function in a short amount of time. So let’s find out exactly which muscles do what.
Gluteus Maximus
The largest muscle in your body, and arguably the most powerful, the gluteus maximus makes up most of the muscle bulk in your backside, and is shown below in green.

Training this muscle will do wonders for the way your butt looks. Stronger muscles naturally have to be larger, and a larger gluteus maximus will give you a rounder and more shapely butt. A well-toned gluteus maximus also prevents saggy butt syndrome.
The gluteus maximus is responsible for extension of the hip in a backwards manner – think swinging your leg back behind your torso, as in plank leg lifts, donkey kicks, or even when walking (though inactive glutes in many people cause other muscles to take over this motion). Gluteus maximus activation also occurs strongly during moves like squats, deadlifts, and hip thrusts.
That’s not all folks. Good old Maximus is a master of many moves and also plays a role in abduction and adduction of the leg (this means sideways motion away from, and towards, the centerline of the body) as well as hip rotation.
Gluteus Medius
The gluteus medius muscle sits as a deeper layer of muscle beneath the gluteus maximus and is also sometimes referred to as your upper glutes.

Gluteus medius is responsible for abduction and rotation of the hip. What does this mean? Abduction occurs when you move your leg out sideways away from your body – in side leg raises, for example. Lateral rotation (towards the outside of the body) of the thigh uses gluteus medius and you can feel this by trying a few clamshell exercises.
Training the upper glutes can help to balance out butt shape and round out the overall buttocks appearance.
Gluteus Minimus
The gluteus minimus is the smallest of the three gluteal muscles, but it still plays an important role in the appearance of the butt. It is located even deeper and directly beneath the gluteus medius, as seen highlighted in the cutaway image below:

The gluteus minimus largely works together with the gluteus medius to perform abduction of the leg. It also is responsible for medial rotation (towards the body centerline) of the thigh.
Other Posterior Muscles
There are deeper muscles located in the buttocks region, but the size and location of these functional muscles (which mainly control does not lend itself well to aesthetic training. Most butt exercises will indirectly train these muscles as well.

Subcutaneous Fat
Subcutaneous fat – meaning ‘below the skin’ – is the layer of fat which covers a great majority of your body. Most people associate fat with being unwanted, but the truth is that in some places we definitely do want to have a healthy layer of subcutaneous fat!
This fat, also known as adipose tissue, sits as a layer above the gluteal muscles. In the right quantities and locations, it can actually look quite nice! Case in point:
The buttocks need to have a healthy layer of subcutaneous fat in order to make tasks like sitting more comfortable. This fat layer is much thicker in women than men, due to hormones which promote fat storage in the gluteofemoral (butt and thigh) region.
Fat distribution around the buttocks region is another large determining factor for the way your butt looks. It is mainly due to genetic factors and hormone levels, and generally it is assumed that not much can be done to change this (apart from cosmetic surgery). Some ethnicities are more prone to store fat in the gluteal region than others.

Losing and gaining weight overall can have an impact on the fat stored in this area, but it’s widely accepted that it’s not possible to naturally ‘spot reduce’ fat or customize the specific distribution of fat on your rear. Fat is lost and gained in layers, (like an onion!) so when you lose or gain fat, this happens in a layer like-fashion over your entire body.

Several approaches to butt-enhancement target the subcutaneous fat aspect of buttocks anatomy. Cosmetic procedures like liposuction, ‘brazil butt lift’, or fat transfer surgeries all alter the subcutaneous fat distribution in the buttocks to give a nicer shape.
If you’re not up for something as drastic as surgery, impacting your hormone levels to affect fat storage is how most butt-enhancing supplement pills like gluteboost propose to work. These are typically natural dietary supplements which are designed to mimic estrogen hormones in the body; as estrogen is the main hormone that promotes natural fat storage in the gluteal region.
The presence of estrogen in women causes them to naturally store more subcutaneous fat in the buttocks region than men; this explains why women’s butts generally appear more rounded and softer than men’s butts.
Aging/disintegration of the fatty layer over time can occur and is called atrophy. Atrophy of the fatty layer (and skin) is what primarily causes butt ‘sagging’. In women, age-related changes in your skin and fat thickness can affect your body shape [3].
Cellulite is a common condition which can occur in the buttocks region, and is associated with this subcutaneous fat layer.
Skin
Skin is the final layer that makes up your buttocks, and it sits above the subcutaneous fat and holds everything in place.
While you might have started out in life with skin as smooth as a baby’s bottom, unfortunately it can be difficult to keep such a nice complexion as we age.
Some common issues that people can have with skin in their buttocks region include stretch marks, pimples and cellulite. While all of these are cosmetic issues only (meaning they only affect your appearance), many people seek to remedy these conditions due to aesthetic reasons.

The skin also atrophies with age, which means that it loses its elasticity and thickness. This can also lead to sagging and poor skin tone. Unfortunately everyone ages, but you can slow this process by living a healthy lifestyle with plenty of exercise and nourishing foods!
Summary
Knowing your butt anatomy can help with influencing the appearance of your butt. There are four main aspects which affect the way your butt looks – bone structure, muscles, fat and skin.
The main ways to change the appearance of your butt is by targeting either the muscle or fat components of the buttocks, or both. Many butt-enhancing surgeries work by altering the fat distribution in the buttocks to give a nicer shape. Butt-enhancing pills supposedly target the fat and muscle layers as well to increase the size of buttocks.
Anyone can change the way their buttocks looks through butt-building exercise which targets the superficial gluteal muscles – my recommended method of attack! Building muscle mass in your gluteal muscles has huge benefits both from an aesthetic point of view as well as a health perspective.
Knowing your butt muscles can significantly help you target them during workouts and assist with glute activation. Which of course will get those booty muscles growing faster!
References:
- Clark BC, Mahato NK, Nakazawa M, Law TD, and Thomas JS. The power of the mind: the cortex as a critical determinant of muscle strength/weakness. Journal of Neurophysiology Dec 2014; Vol. 112, no. 12:3219-3226 (Abstract here)
- Ranganathana VK, Siemionowa V, Liua JZ, Sahgalb V, and Yuea GH. From mental power to muscle power—gaining strength by using the mind. Neuropsychologia 2004; Vol. 42, Issue 7:944–956 (Abstract here)
- Murakami M, Arai S, Nagai Y, Yamazaki K, and Iizuka S. Subcutaneous fat distribution of the abdomen and buttocks in Japanese women aged 20 to 58 years. Appl Human Sci. July 1997; 16(4):167-77 (View here)
I LOVE how thorough you are here with this information! Also appreciated the illustrations 😛 So much butt-pertinent info here that I would never have even considered. Thanks for getting my wheels turning. Learn something new every day at the “better butt challenge” 😀
Much appreciated Cat! I do my best 😛
Wow, what an awesome post!
I took an Anatomy and Physiology course in high school, so that’s why I was immediately drawn to this type of article.
Great info 🙂
Thanks! I also don’t mind a bit of anatomy, and definitely had fun doing research for this article!
This is really awesome. I had no idea our butts had all dis attributes n d pictures are amazing. Helped me recognize mine. Wonderful article right here
Thanks Beverly, I am glad this has helped!
As one whose dear wife of 54 years is being subjected to monthly Faslodex injections in the hip (both sides), I am concerned about whether these are affecting the Piriformis Muscle, and resulting in 4-5 days of severe pain following her monthly treatments.
What type of physician should I contact to get positive answers regarding precise methods of injections to avoid damage to the piriformis. I am not convinced that the technicians doing the injections are well trained in the anatomy of this region, and I am seeking information to aid in their education.
Thank you for any assistance.
Hi Clifton, So sorry to hear your wife is unwell. I sincerely hope this treatment works and improves her health.
I’m definitely no expert, but I think your best point of call may be to try and contact the faslodex manufacturer directly to see if they can advise on the correct administration of the drug. I checked out the information available online and it says ‘Intramuscular injection’ into each buttock, and that there may be some pain around the injection site. It could be just a side-effect of the injection, but I imagine that the manufacturers of this drug would be in the best position to advise.
Alternatively, maybe a physiotherapist may be able to assist? In my experience physiotherapists are typically very knowledgeable when it comes to anatomy and they may be able to advise on exercise treatment or comment on if they think such injections might have an effect on the surrounding muscles/tissues.
That being said, I would have expected the injection to be into the gluteus maximus which is one of the largest muscles. As far as I am aware the Piriformis is quite a small muscle and located quite deep, but this muscle can potentially cause irritation of the nearby sciatica nerve, but I believe this causes a very distinct kind of pain. A good physiotherapist would be able to advise further on this.
Wishing you the best of luck with finding out more about this.
Jolie
I just finished the squat challenge,(and it wasn’t as hard as I thought it would be!) so it’s nice to read a little more insight in the “butt” and what is actually going on down there. Thank you 🙂
Awesome to hear Ava, no problem!
Hi my name is Jeff and I am a disabled man in a wheelchair my butt is always hurting I looked away this could be invite your description I now know thank you.
Thanks for stopping by Jeff! I hope you are able to find some relief.
Does yourbut have a bone in it like the butt cheeks
Not specifically, but your pelvis does have two kind of lumpy bits at the bottom of it, that are basically your ‘sit bones’ – these are what you might be feeling as the bones in your butt cheeks, because they come into contact with a chair when you sit down (especially if you have a particularly ‘bony’ butt).