Anatomy of the Lower Back

hip_musculature_spinal_support

(Part 1 of 2: Muscular Skeletal System)

If you have practiced yoga lately, chances are that you sat on the floor for a little while. This is a very healthy activity that every human should probably practice regularly for the strength of the pelvic floor muscles, and to allow the inner thighs and hips to relax. You can always work your way into it with blocks, props, cushions, pillows; you can do it while watching TV. It is good for releasing the muscles in the lower spine which have a strong connection with the hips, pelvic floor, abdominal muscles, lower back, and lower organs, including the sex organs and excretion organs; it’s good for all that important stuff.

In this article, I will speak specifically about the lower back and the anatomical features that you will want to be aware of as you practice yoga. If you have any of the following symptoms, you may want to begin a restorative yoga practice to assist in the alleviation of your pain, as well as begin to sit on the floor regularly. If it is too painful to start, contact a specialist or something like that, here are some symptoms of dysfunction:

  • Pain and stiffness in the back.
  • Pain in the buttocks and the legs, often in the back of the thigh.
  • Pain that worsens when bending, stretching, coughing, or sneezing.
  • Sciatic Nerve pain (pain in the hips, or back of your legs that shoots down the leg)

The lower back is really composed of three areas of the body: the lower spine, the hips and tailbone, and the abdomen. Since the spine is encircled by musculature, the abdomen, spinal muscles, and hips are all integral aspect of maintaining a healthy lower spine and therefore lower back.

Here is a depiction of the skeletal frame with the lower back in red: lumbar_region from wikipedia

You can see the there is a lot of big bone support at the base of the spine you will know from your own body that your hips provide the support for the lower spine. The ribs and upper legs have a tremendous amount of connection with the lumbar region of the spine and are the primary support structures in providing space for the lower back and lowest organs. Here is a very detailed depictions of the inner hips muscles and lower spine: hip_musculature_spinal_support

This is a depiction of the primarily of the psoas muscles and illiacus muscles. The psoas is a primary muscle group that moves the trunk Gray's Quadratus Lombrumand is greatly affected by sitting habits. It lines the font of the spine and inserts separately into each vertebral process up to the T12 in most people. The illacus muscles line the insides of the hips and connect with the psoas at the insertion point of the lesser trochanter of the femur. Both the psoas and the QL run along the lumbar spine to the trunk, the QL going posterior to the spine and the psoas anterior to the spine, bone are connected to the transverse spinal processes. The muscles work together to move the trunk, along with the muscles of the abdomen. The psoas and the QL muscles are the primary muscles of the lower back, so we’ll come back to them.

There are a few more groups of muscles to pay attention to, but other primary muscle group to consider when talking about the lower back is the abdominals. Your abdominals provide frontal support for the spine, but in addition to the abdomen and primary lower back muscles of the Psoas and Quadratus Lumborum, the diaphragm, obliques, serratus muscles, pyramidalis muscles, levatores costarum, subcostal muscles, transverse thoracis muscles, and intercostal muscles play roles in the alignment of the lower spine. The final, possibly most under looked muscle is the latimus dorsi, which runs all the way along the back of the spine up to the shoulders. We can go over most of them as accessory breathing muscles, which is an action largely affected by the lower spine. It sounds like a lot of muscles because there are lots of muscles that are connected to your lower back. Let’s break it into pieces to see how it works.

Lets start at the top and work out way down the body, so lets start with the shoulders. The serratus muscles, obliques, levatores costarum, costal muscles and subcostal muscles all play a role in spinal alignment at the shoulder level. The subcostal muscles are the subcostal_muscles_ depictioninnermost, being inside of the rib cage, and surrounds the diaphragm along the ribs. The intercostal muscles are just superior, or further outside than the subcostal muscles. The levatores costarum run along the back of the spine on the outside of the rib cage, "Levatores costarum" by Uwe Gille - modified from Image:Gray389.png. Licensed under Public Domain via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Levatores_costarum.png#/media/File:Levatores_costarum.pngproviding even more support for the spine, which you can see act in opposition to the interlacing rib muscles. Notice the spinal erectors and spinalis muscle groups. You can also see how the muscles interweave with the spine and ribs, making breathing a full body movement. This is why forward folds are so effective at releasing the muscles the support the spine, so that they can stretch and relieve tension. This part of the reason why breathing in yoga can help to align the spine, and why spinal alignment and breathing have a close relationship. The obliques are a portion of the abdomen that you can read more about here. The serratus anterior is the another muscle to consider, which is also known as the punching muscle, as it pulls the shoulder blades forward. This is an extremely strong and useful muscle in yoga that supports you in handstands, forearm stands, and headstands in specific variations with proper alignments. and keeps the shoulders aligned, which then keeps the spine aligned. Like links on a chain. The final muscles to look at is theLatissimus_dorsi latimus dorsi, a muscle that runs from the lower back to the outside of the shoulder blades. The muscle connects the arms to the lower back, so can be really important for golfing, blowing, javelin throwing, or boxing. Anything where you are using your hips to power the upper body. These muscles can be easily overlooked in sun salutations, especially downward dog, which can allow the spine to hyperextend. This muscle is also more active in the elbow close push up, allowing the serratus anterior and lats to move the spine up from chaturanga into downward dog. Hollowing your armpits in plank/chaturanga/down-dog will likely activate and strengthen your lats, but its good to have a second pair of eyes on your alignment, so if you have questions find a local studio or teacher and ask them about your down dog. I’m sure they will be thrilled to answer your questions.

The last muscles to consider are the diaphragm, the obliques, the

Diaphragm
Diaphragm

pyramidalis muscles, and the transverse abdominus. The final piece of the puzzle is the rectus abdominus, which acts in direct opposition to the Psoas and QL muscles. The pyramidalis muscles are tiny triangles below the lowest layer of the rectus abdominus, and they form muscles just above the genitals. The diaphragm forms the inner musculature needed to move the ribs as the lungs expand.

abdomen image from http://www.usra.ca/The obliques line the outsides of the torso at the bottom of the rib cage, and all four layers of abdominals meet at the linea alba and run down to the pyramidalis muscles. You can see the lowest layer of the abdominals, the transverse abdominus, which acts as a kind of weight belt to support the lower spine when heavy lifting with the back, or squatting. It works with the psoas and QL to keep the trunk stable. The rectus abdominus acts in opposition to the QL and psoas, which forms a kind of push-pull system for you to lean forward and back, to squat, and to jump. Think of them as working against each other, but really they work in unison to support your spine. A great way to feel all of these muscles is to do burpees and/or sun salutations.

That wraps up the muscular and skeletal portions of the anatomy of the lower back. Please check back in about a week for the second section where I discuss nerves, organs, blood vessels, and fluid distribution, and if you are looking for something a bit more entertaining, you can check out the WANDERER series, I am working on part 13 right now and should have it out in a few days. Thanks for reading, would love to hear any questions or feedback

 

The Anatomy of the Abdomen (part 4/4: Rectus Abdominis)

rectus_abdominis

The Rectus Abdominis is a paired vertical muscle that runs from the xiphoid process at the bottom of the sternum, across the top of the 5th and 7th ribs and down to the pubic symphysis, pubic crest, and pubic tubercle below the hip-line. The two muscles are separated by the linea alba running down their center, which is a connective band for the muscles. The rectus sheath holds the muscle; it is also the insertion point for the lateral abdominal muscles. The tendinous intersections cross the muscle, separating it into eight distinct squares, or bellies, the top 6 of which form the “six pack”.

The rectus abdominis is used to flex the lumbar spine, the lowest 5 vertebrae of the spine. It is also a very useful muscle for breathing; it is used during childbirth, defecation, and forceful exhales. The muscles flex in pairs, which allows for efficient recruitment when forward folding, or putting legs over your head in plow. The muscles aid in lifting the trunk and are the muscles activate in traditional crunches. Usually the first tendinous intersections cross just above the belly button and the second line crosses between the sternum and first tendinous intersections. They belly button is known as the umbilicus in anatomy nomenclature.

There is some misinformation about the rectus abdominis muscle that really should be cleared up. The first, is that working on the muscle is not what gives people definition in the six tendinous intersections called a “6 pack”. Levels of body fat are a more accurate determinant for whether a person’s abdominal region will be well-defined, or not. Usually, this starts around the 15% and lower for men, though there are always outliers and special cases. However, once you are at that level of body fat, the amount of exercise and abdominal activity present in your daily life will affect the definition of the abdominal muscles. Another myth is that regular crunches are ineffective. Regular crunches are some of the most effective activity for activating the rectus abdominis muscle alone, if they are done properly with exhalations to peak and a vertical lift of the chest rather than leaning towards the knees. In other words, the efficacy of crunches are determined by proper alignment.

I find that bicycle crunches done slowly are still the most effective abdominal workout for me. 5 minutes and I am toasted. Slow down when doing the exercises, use your breath to move your body mindfully and in unison. Some great stretches for the rectus abdominis muscle are upward facing dog, cobra, downward facing bow, and wheel.

What are your favorite ways to stretch and strengthen your abdominal muscles?

 

The Anatomy of the Abdomen (part 3/4: Transversus Abdominis)

Transversus_abdominis

Part I
Part II

The Transversus Abdominis is the deepest layer of the abdominal wall, underneath the internal obliques. It stabilizes the mid-back and pelvic areas. Since it is the deepest layer of abdominal tissue, its function is important is activating the other muscles of the abdomen and stabilizers in the spine during dynamic movement. It is also implicated in most spinal injuries though the scientific community is in debate about how much effect the muscle has on lower back dysfunction.

The muscle originates in the borderline of the ribs, the front of the hip plate and the inguinal ligament, and the lumbar fascia. It joins the rectus sheath (6 pack muscles outlined in the abdomen) at the front of the abdomen and inserts in the linea alba. It joins at the front of the pubic bone via the conjoint tendon, which often conjoins with the internal oblique, but can also be separated.

The transversus abdominus muscles is also known as the corset transverse_abdominismuscle, because it holds in the organs and abdominals. It is innervated, or activated, with T7-T11 and nerves from the hip plate
and is extremely useful in stabilizing the spine. Its activation is not affected by the arms and it is the primary muscle activated during breathing, making it extremely important to yoga exercises and for life in general. The muscle is activated fairly easily during breathing and can help to ease to movement of breath in the body, making it easier and more efficient for the respiratory system to function.

So lets review all of this information in the light of breathing in yoga. Because the transverse abdominis muscle is the deepest muscle, it is the most used for breathing many anatomists believe for supporting the spine. It is definitely heavily used in conjunction with the oblique muscles to assist the diaphragm in breathing. This is also the muscle that coordinates the others, recruiting the other muscles under heavy strain. This is why setting a breath pace at the beginning of a yoga class is extremely useful; you are setting the muscle memory for your breathing muscles. I like to use breath retention exercises early in the practice to set a tone of slow, and deep breathing, using all of the muscles in connection and concert together.

There is one particular exercise that is amazing for working the transverse abdominis; leg raises with the knees at least in a 90 degree angle. Feet lower to the floor and extend forward as they lower. Lower back stays on the floor and you should inhale the feet to the floor and exhale the knees back up to 90 degrees. Take about 30 repetitions, go as slow as you can while moving with you breath.

Being an important breathing muscle also makes the transverse abdominis an important muscle for the organs and their movement during respiration. We will definitely be revisiting this muscle as I write posts on breathing exercises and yoga poses. Leave a comment if there is anything else about the abdominals you want me to write about in the final post about the rectus abdominis.

The Anatomy of the Abdomen (part 2/4: Internal Obliques)

internal_oblique_from_http://fitsweb.uchc.edu/student/selectives/Luzietti/hernia_anatomy.htm

The internal oblique is just below, or beneath the surface, of the external oblique. The fibers of the internal oblique run perpendicular to the external oblique; this cross-stitching of the muscles give the internal obliqueoblique a tremendous amount of stability and are extremely useful to the respiratory system in breathing and providing support for the organs while they move with the expansion of the lungs. You can see the difference between the internal and external obliques on the photo to the right; the external oblique is located superficially, or closer to the skin, than the internal oblique.

The origin points for the internal obliques are the thoracolumbar fascia along the spine, the front of the hip plate, or iliac crest, and the bottom of the hip plate along the inguinal ligament. The insertion points are the linea alba, the concave vertical centerline of the abdomen and the rib cartilage of ribs 8 through 12. It stitches up the front of the midline up and back, away from the ground. This muscle is very active in the retention of Uddiyana Bandha, though probably less active than the transverse abdominus muscle. The muscle covers the belly from the bottom of the ribs to the sitting bones.

Great ways to activate the internal obliques are with isometric exercises to press the arms against the legs, possibly while lying on the back or standing. The muscle spreads up towards the mid-line, so using the airs to stretch the torso will also help to activate the muscle group. Side plank (Vasisthasana) with your leg lifted, standing back-bends, and locust poses can get these muscles active. Anything where you are reaching up with the arms and a straight spine will activate the torso muscles all the way down to the lower internal obliques. Warrior 3 is a very active pose and is awesome for warming up the sides of the body, as are side angle and half-moon pose. When the body is working in concert, it is most powerful. The breath is the composer.

The internal oblique is a major muscle for moving internal organs on exhalations and making room for the chest cavity to expand. It, combined with the transverse abdominus muscle and diaphragm, are major muscles you feel while you exhale. The muscle has a second major function, which is to move with the external oblique to creation torsion in the spine. when you lift one shoulder and lower the other, you active the internal and external obliques simultaneously. The muscles work in opposition to keep you and your spine upright so that you can stand and more importantly, walk and run.

 

 

 

Anatomy of the Abdomen (part 1/4: External Oblique)

external oblique

The abdominal wall consists of four distinct muscles, the transverse abdominus, the internal obliques, the rectus abdominus, and the external obliques. These muscles form three distinct layers, with the rectus abdominus and external obliques on top. The transverse adbominus forms a kind of belt around the lower spine and the internal obliques stitch together up towards the ribs while the external obliques stitch together down from the serratus muscles to the top of the iliac crest.

The external obliques interlace with the intercostal muscles to support movement of the ribs and spine. They are most important for rotation of the thoracic spine and is what allows for stabilization while twisting and for support during flexion.

The insertion of the upper fibers occurs at the 5th through 9th ribs where they interlace with the serratus muscles and the 9th through 12th ribs interlacing with the latimus dorsi. The origin of the muscle is at the linea alba, the centerline of the abdomen and the front portion of the iliac crest and the upper part of the pubic tubercle. The external oblique is the largest of the three muscles on the outside of the abdomen.

The muscle fibers of the external oblique run inwards, towards one another, and down towards the iliac crest at the outside of the hips. origin of the external obliqueThe muscle has eight muscular peaks for each of the eight ribs that it crosses over. The oblique runs down to the Iliac Crest where it inserts into the top of the hip plate and forms the inguinal ligament, which connects the top of the hip crest to the pubis bone at the bottom of the pelvis.

You activate the external oblique in side plank and stretch them in chaturangas, but there are enormous amounts of exercises to target the muscle. The next layer of abdominal muscles just underneath the external oblique is the internal oblique, which will be part 2. Check back soon to see part 2!