Learn more about the anatomy of the body to better understand safe and stable physical alignment in yoga poses. Pick up in-depth knowledge to take to the mat to fine-tune and deepen your practice.
What is Yoga Anatomy?
There’s a lot to learn about the human body and it’s easy to get overwhelmed. As a yoga teacher, it’s helpful to remember that the biggest reason to discuss anatomy is to facilitate healthy practice and help students understand what’s going on in the body.
If you’re not sure where to start, here are some key aspects of anatomy that are helpful to know. One note: When I say “major” in the list below, it refers to the more commonly-used parts of the body versus every little bone or muscle contained therein. This doesn’t mean you may not want to learn this additional information; it means it’s a place to start.
Knowing the names of all the muscles and bones isn’t essential to practice yoga…
…but being familiar with some basic terms can help! If you don’t have a background in anatomy (or if your memory just isn’t what it used to be) this guide can be a starting point.
Parts of the spine
The spine is made up of four areas: the cervical (neck), thoracic (upper back, ribs), lumbar (lower back) and sacral (sacrum and tailbone). The cervical and lumbar curves in the spine are described as lordotic (inward or concave), while the thoracic and sacral curves are kyphotic (convex). The spine, skull, rib cage and sternum (breastbone) together make up the Axial Skeleton.
The pelvis is made up of the sacrum and coccyx (tailbone) at the back, and two hip bones. The hip bones start life as three bones per side – the ilium, ischium and pubis and eventually fuse together as we develop.
The sacrum is five fused vertebrae which form the triangular shaped bone at the base of the spine. The ilium joins to each side of the sacrum at the sacroiliac (SI) joints. You may hear about the SI joint in yoga classes as it’s an area that can be vulnerable to injuries or imbalances.
The sit bones
The ischium bones are at the bottom and back of the pelvis. They have a larger part at the underside of the bones called the ischial tuberosity and it’s these bony protrusions you’ll hear described as the sit bones (or sitz bones/ sitting bones).
The three hip bones form a cup-like, concave structure called the acetabulum. This is where the head of the femur – the ball shape at the top of thigh bone – sits in the pelvis and creates the hip joint. The femur runs down to the knee joint where the patella (kneecap) is and meets the lower leg bones – the tibia and fibula.
The shape and position of the acetabulum vary from person to person, as does the angle of the head of the femur. This is important to consider in yoga as it could be the structure of your ball and socket hip joint which makes some poses seem easy or impossible, rather than flexibility or the amount of practice you put in.
The shoulder joint is made up of the scapula – shoulder blade, clavicle – collarbone, and humerus– upper arm bone. The humerus runs down to the elbow joint meeting the two bones of the forearm – the radius and ulna. As with the hips, the structure of the shoulder joint will play a role in how accessible some yoga poses are.
Terms relating to the location in the body
Anterior and Posterior
When something is anterior it is nearer to the front of the body. Posterior means closer to the back of the body. You might hear these terms in relation to the tilt of the pelvis. Anterior pelvic tilt is when the front body parts of the hips (the tops of the ilium) move forward and down, creating a more pronounced arch in the lower back.
Medial and Lateral
Medial is closer to the center line (mid-line) of the body running from head to toe. Lateral is closer to the sides of the body.
Proximal and Distal
Proximal refers to something closer to the torso of the body and distal is further away from the torso. So the distal end of the forearm is close to the wrist and the proximal end is closer to the elbow.
Anatomical Planes – or Planes of Movement
There are three main anatomical planes in the body. These are flat plates or surfaces that divide up the body. Movements can be described as taking place in one of these planes, or in parallel with them.
This vertical plane runs down through the center of your body dividing up the left half from the right. The term sagittal comes from the Latin word sagitta meaning arrow – so it might help to think of an archer raising an arm up and back to take an arrow out of the quiver, drawing their arm back and firing the arrow forward. All these actions are in the sagittal plane. Most of the movements in Sun Salutations also take place in the sagittal plane.
This vertical plane divides the front and back portions of the body. Coronal is from the Latin corona meaning crown or garland (although, personally, I think a pair of headphones is a more helpful image). Performing a cartwheel or moving from Warrior II into Triangle pose take place on the coronal plane.
A horizontal plane like a table top which divides the upper (superior) and lower (inferior) halves of the body. Twists take place in the transverse plane.
While you might not hear these planes being referred to directly in class they can be helpful to bear in mind so that you are regularly moving in all three planes. We tend to move mostly in the sagittal plane – even the shape of our yoga mats encourage this.
Terms relating to the movement
The study of movement is called Kinesiology. For all these terms assume you are starting in the Standard Anatomical Position which is standing up with the arms to your side, palms facing forward thumbs out.
Flexion and Extension
These are movements that take place in the sagittal plane. Generally speaking, when you bring two bones towards each other the joint is in flexion – when you move them away from each other this is an extension. Hugging your knees to your chest brings the knees and hips into flexion. In a standing forward bend, the knees are in extension but the hips are still inflection.
When joints can move both forwards and backward – like the neck, spine, and shoulders – it is called flexion when the movement is forwards (anterior) and extension when the movement is backward (posterior). So for example, your neck and spine are in flexion in Cat pose (tucking the chin to the chest and rounding the back) and extension in Cow Pose. Raising your arms overhead in Tree pose brings the shoulders fully into flexion, they are an extension when you reach back to your heels in Camel Pose.
You may also hear the instruction to “extend your spine” meaning lengthen – technically this is Axial Extension which is a movement to lengthen out the spine by reducing the angle of the curves.
Adduction and Abduction
These movements take place in the Coronal plane. Adduction is the action of bringing the arms or legs towards the center of the body, or mid-line (Adding together). Abduction moves the limbs away from the center. So from the Anatomical Position (see above) raising the arms to the sides would be an abduction.
Internal Rotation and External Rotation
You’ll often hear about rotation in relation to hip opening poses. Internal (medial) rotation brings the fronts of the thighs towards the center as in Supta Virasana and Utkatasana. External (lateral) rotation brings the fronts of the thighs away from each other as in Lotus pose or Baddha Konasana. You may find internally rotated hip openers easier than externally rotated hip openers or vice versa depending on the structure of the hip joint as we mentioned earlier. Whichever way your hips are rotating, check that the movement comes from the hips and not the knees so that you don’t twist the knee joint at all.
The terms also apply to the shoulders and arms. For example, in Downward Dog the upper arms are externally rotated and the lower arms are internally rotated so that the hand is flat on the floor but the shoulders are not pinched. It’s also common for one arm to be internally rotated and the other externally rotated for example in Gomukhasana or where the arms are binding in variations of poses like Utthita Parsvakonasana.
Here are 7 Benefits of Meditation
1. Major movements of the body.
Yoga is a practice of connecting movement to breath. “Movement” can be described in various ways, but in order to understand it from an anatomical perspective, we need to know the planes of the body and how moving different body parts create actions such as flexion, extension, and internal and external rotation. The challenge isn’t in understanding these movements in theory; it’s in applying them to different body parts and poses. Often in one pose, there can be 3 or more actions taking place concurrently.
2. Major bones of the body.
The body is comprised of 206 bones; there are 26 in the foot alone. While it might be your passion to understand and be able to name all 206, it may not be necessary in order for you to develop a baseline of understanding for teaching yoga. Certainly, bones in the arms, legs, and torso are essential to know in order to understand the basic structure of the body. Also, knowing the names of the bones will come in handy as you start to review the origin and insertion of the major muscles.
3. Major joints of the body.
We know yoga is a movement-based activity and we know the body is made up of bones and muscles (among other parts). Joints are between bones and understanding the types of joints in each part of the body has significant implications for the kinds of movements that are safe and accessible and the kinds of movements that are riskier, especially depending on a practitioner’s knowledge, the degree of strength and flexibility.
There are several types of freely movable joints (hinge, ball, and socket, gliding, ellipsoid, pivot, and saddle). At a minimum, it’s helpful to understand each one and to identify some parts of the body where they appear.
4. Major muscles of the body.
This is one of the toughest topics to wean down to just what is “essential.” The easiest way to begin? Start with body parts, like “trunk,” or “shoulder,” and “hip,” and examine the muscles in these areas. One book that does this quite well is Blandine Calais-Germain’s, Anatomy of Movement.
5. The structure, composition, and function of the spine.
The spine is the central axis of the body and as such, understanding it’s composition, function and surrounding muscles can help you in the presentation of poses as well as creating custom sequencing for students experiencing back pain, injury or chronic conditions. Start with its physical structure (bones, joints, and discs) and work outwards (muscles, tendons, and ligaments).
6. Muscles in action in the essential yoga pose.
Just as we have to start somewhere in order to start our review of muscles and bones, we have to start somewhere when it comes to applying this information to the postures! Start out by taking 5 standing postures and identify the muscles in action. A good book for reference is Leslie Kaminoff and Amy Matthews’ book, Yoga Anatomy.
7. The alignment that could put the body at risk.
Once you have a basic understanding the components of the body, its movements, and have reviewed key poses, you can begin to understand the kinds of movements that put the body at risk. For instance, understanding that the knee is a hinge joint helps us recognize that flexion and extension are healthier movements than taking the knee into flexion as you would see in a pose such as Pigeon (where the shin is moved to the side). Understanding how the spine works can help us as we work with people in forwarding bends.
Yoga teacher training include anatomy as part of the basic 200-hour program. How this information is presented can make a huge difference in terms of your ability to absorb the information. Presentations that include both the key information but also practical examples (such as identifying which muscles are needed for an effective transition from High to Low push up) can be wonderful for helping you walk away with information you can use in your classes.
Remember, your role as a yoga teacher is to understand anatomy in the context of yoga. Also know that as students ask questions about sensations, pain or tightness in their bodies, don’t be afraid to say, “I don’t know,” and go look up the information.
Be sure to get back to them so you can test your ability to speak freely about what you’ve learned. Another way to test your knowledge is to create sequencing around different movements, muscles, and joints. So, for instance, creating a class around hip flexion, extension, internal and external rotation gives you a chance to learn the muscles that create these actions and create a sequence that supports them.
Most of all, recognize that understanding this information takes time and is really a life-long endeavor.
Have patience and enjoy the learning!
Pelvis and sacroiliac joinHip and leg bones