Anatomy of Asana: The Pelvis and the Leg
Homework review or practice for Sunday: do some poses from the anatomy of the leg/asana class
[you should look at a picture of a skeleton for a bit, or a real one if you can manage it (legally, I mean), and get the larger picture of the many functions the pelvis has in our bodies.]
1. Assists and anchors the leg in stable positions and in locomotion. Yogically, the leg is considered one of the karmendriyas, the karma + indriya = karma organs, or organs of doing or action, in this case, the organ of locomotion.
The pelvis anchors and supports the trunk, arms and head in all positions and movements. The pelvis is an anchor of the muscles that support the trunk all around its border, and some of those muscles also directly support the other organs of action, the arms. These are the organs of giving and receiving.
The pelvis is the location of the reproductive karmendriyas and the eliminative karmendriyas.
We have noted the shape of the female pelvis is different from the male pelvis in order to allow room for the fetus to grow into a full little person (a wide, open upper border and shorter wider pelvic shape in general), and to deliver that one into the world safely (a deeper and wider pelvic floor and mobile pubic symphysis and sacroiliac joints to accommodate the skull of a full-term infant. Regarding the organs of elimination, the pelvic floor also provides exit ways for solid waste from the intestinal tract and liquid waste from the kidney-bladder filter.
And even though it is seemingly a stretch to say this, the pelvis, particularly the groins, are the anchor points for the last karmendriya, the organ of speech. An important musician to us Austin Yogis is Pandit Mukesh Desai, who has accompanied our beloved Ramanand Patel in teaching us about Yoga and Sound. He has taught us that the free voice originates in the groins, and nowhere else. Like the root of all our action in the world is from the base, the root of us, the root of the voice is in the anchored, grounded, pelvis. And an ungrounded pelvis weakens the breath and the voice, or an incomplete connection from base to voice weakens the voice.
So from the above we see that the pelvis anchors all the karmendriyas, the organs of action. It is the Grand Central Station of all the physical forces at play in any movements or stabilization of the body, pretty much anywhere, anytime.
The pelvis has a bone in it—the sacrum—that is part of the spine which contains and protects the Central Nervous System. The mind and the five senses are the jnanendriyas, and the spinal cord and it's protector, the bony spinal column is part of that system. The stability and health of the pelvis affects everything from the transmission of nerve signals to and from the lower body to the stability and even the nature of the thoughts that arise in the mind of the individual.
2. The pelvis is a sort of Grand Central Station of physical forces at play in movement or stabilization of our body, where the different energies and forces of the body meet (pelvis/spine joining) and divide (pelvis / legs), changing lines to move either up- or down- or even crosstown (laterally and diagonally). The sacrum is a key player in the pelvis.
3. Forms a basket-shaped container for the pelvic vital organs, which will be covered in further anatomy lessons, but we need to know a few connected ideas.
5. At its lower end, it provides of entry and exit ways for reproduction and digestion products. We will discuss the reproductive and digestive systems in further anatomy lessons, but this clearly figures in the discussion of structures and functions of the pelvis.
6. energetically, it is the root and ground of our beings. 1st chakra primarily and above that the 2nd chakra-- muladhara and svadisthana-- are in this pelvic region, the vayu apana governs here, the earth element primarily and above that the water element rule here, and all this yogic anatomy part is for another lesson too.
We won’t get into this too much. But just looking at a skeleton, remember that chakras open in a forward-facing direction.
The acetabulum (hip socket) in the pelvis has a surface consisting of the three pelvis bones joined: pubis, ilium, ischium, entirely fused in the acetabulum/hip socket itself.). Note this joining of bones is not considered a joint in any conventional sense. There is no movement there.
The only joints with any mobility at all in the pelvis are the two sacroiliac joints in the back, and the pubic symphysis in front. And we are not talking all that much movement over all, though a total of a centimeter tipping or spreading of the pubic symph and SI joints happens all the time in childbirth and is really quite uncomfortable. That is a huge amount of movement, really. Go ahead and you try to move your own …no, please don’t.
This is a key point: the pelvis structure is the most stable and hard to move even where it is built to move, than any other structure in the body.
Just some more yogic perspective here: the central core of the body, the pelvic region, is as we have noted, a very strongly fortified region, with the walls of the pelvis surrounding several vital organs, and also new lives in the early stages. It is fortified and not very mobile, and the further away from this dense and bony core, the more mobile we become. The arms and legs are less bulky and dense and can move relatively quickly; the feet and hands are the lightest and most mobile of all; and let’s not forget the head, which while heavily fortified in bone, contains the brain, which hosts the mind, most etheric of all). We go from light and mobile in the head and extremities, to heavily fortified and stable at the core/base.
So the pelvis transfers the weight of the trunk into the legs efficiently. And compared to the shoulder ball-and-socket joint, the hip joint has relatively less mobility and relatively greater stability. But relative to the pelvis, the hip socket has great mobility. And as compared to cervical vertebrae, the 5th lumbar has very little mobility, but relative to the sacrum, it has lots.
PALPATION OF PELVIC STRUCTURES
1. Lie on your back and locate:
Anterior Superior Iliac Spine, pubis, pubic symphysis, the line of the iliac crest with its thicker and narrower areas.
Note: the vertebra level with the very top of the ilii is L4. L5 is below that, and most lower lumbar vertebrae in most people are so deep-set into a bed of muscle and ligament that only the outer tip of the large posterior process are palpable. You have to flex your hips a lot, drawing your knees toward your chest, to feel much of the L4 and L5 vertebrae.
2. Turn to your side and feel
Posterior superior iliac spine level with S2 and centers on the SI joint.
The ischial tuberosity.
If you feel between the ischial tuberosity and the outer thigh bone (greater trochanter), that is the section of the lower pelvis where the sciatic nerve passes into the thigh from the pelvis.
3. Roll to your back again and
Locate the femoral triangle by placing R foot on L thigh above knee and externally rotating R leg to expose the groin area passively: femoral triangle borders are Adductor longus, Sartorius and the inguinal ligament between pubis and ant sup iliac spine. You can feel the artery, lymph nodes closest to pubis, you can feel the psoas bursa if it is inflamed. If you dig you can palpate other adductor muscles, carefully. The hip joint lies deep to the center of the upper, inguinal, line of the triangle, but cannot be palpated. The hip joint cannot be felt because of the tendon and fibers of the psoas muscle cover it in this position first, and then the very thick anterior joint capsule.
4. Roll to your side again and find the
Greater trochanter/outer pelvis:
The soft tissues that cross the bony posterior portion of the trochanter are protected by a bursa. Feel for ‘bogginess’ due to the irritation or inflammation of the trochanteric bursa (bursitis). Can’t feel bursa unless it is inflamed.
Gluteus medius attachment.
5. Sciatic nerve:
Midway between greater trochanter and ischial tuberosity. When the hip is extended, the gluteus max covers it; when hip flexed, glut max moves out of the way. Find midpoint between the ischial tuberosity and the trochanter and press to maybe feel nerve. This is how you figure out if it’s sciatica or bursitis—palpate directly to find out which is the tender part. You will know it’s the bursa if the soreness and maybe even swelling is on the trochanter of the femur rather than the sciatic nerve pathway.
6. Iliac crest again:
On the superior border, Gluteus medius and Gluteus minimus muscles originate just below the border, and Sartorius and Rectus femoris attach right at the Anterior superior iliac spine (ASIS).
Note: gluteus maximus attaches to the sacral border of the ilium joint mainly and attaches at the outer trochanter and shaft of the femur. So the gluteus maximus has a bit of a diagonal axis, from sacrum to femur
REVIEW OF PELVIS-LEG MUSCLES FROM LAST SESSION
(please relieve the tedium and skip this if you already learned it. Scroll to the next section below, “ Even More Pelvic Muscles”.)
Remember these quadrants:
anterior surface = Flexor Muscles attached to Pelvis:
Note all these muscles run more or less parallel to the axis of flexion and extension of the legs and lower spine.
Psoas and Iliacus: share common tendon inserting into the lesser trochanter. Psoas is the most powerful of the flexors and has the longest range (lesser trochanter of femur to 12th thoracic vertebra.) Psoas also produces lateral rotation. We treat the psoas with great respect and think of it as a powerful stabilizer of both spine and pelvis. It is the most powerful of this group and one of the most powerful and influential muscles in the body.
Sartorius: mainly hip flexor; secondarily abduction and lateral rotation. Also acts on knee in flexion and medial rotation. It is very strong in flexion. It helps keep the pelvis upright. Connects the pelvic movement directly to the knee (crosses both joints)
Rectus femoris: powerful flexor, especially so when the knee is flexed, as is walking/running. Connects the pelvic movement directly to the knee (crosses both joints)
Tensor fasciae latae: hip flexor and pelvic stabilizer.
Pectineus: primarily an adductor, a very short muscle close to pelvis.
Adductor longus: primarily an adductor but also partially flexor
Glutei minimus and medius, only most anterior fibers do the flexion.
Medial quadrant = adductor grouping
pectineus, closest to pelvis, attached to pubis and upper shaft of femur
adductor longus, most superficial and longest
adductor brevis mid level adductor
adductor magnus. Big flat muscle, lower adductor
Note: these are only pelvis-to-femur connections. There are no connections directly to the knee joint.
Lateral quadrant = abductor grouping
gluteus medius, most superficial and most imptortant abductor. Inserts into anterior and
lateral aspects of trochanter.
Note on the lateral side of the femur connecting from pelvis to the knee, is the Ilio-tibial band, (IT band), a major player in stabilizing the pelvis and leg structures, that is not a muscle but rather lots of fascial tissue, and which gives us humans lots of trouble when it is relatively tight.
posterior quadrant = extensor grouping
Two main groups, one inserted into femur and the other around the knee joint.
Group 1 (the ones broadly attached to the upper border of the pelvis):
Extensors broadly attached to ilium:
Gluteus maximus, gluteus medius, and gluteus minimus (note g med and g min are mainly abductors but act as helpers in extension. )
Gluteus maximus: by far the strongest muscle in the body and also the biggest. Attaches to both the sacrum and the ilium. Makes a big fan of muscle. Assisted by posterior glutei medius and minimus. Also lateral rotators help with extension some, though that is not their main function.
Group 2 (the ones attached to the base of the pelvis):
Extensors narrowly attached to sit bones: hamstring muscles:
Biceps femoris (outer knee/fibula attachment),
Semimembranosus and Semitendinosus. Together, they are 2/3 the strength of g.maximus. These are biarticular muscles (cross both hip ad knee joints), and their efficiency depends on the position of the knee. Locking the knee in extension helps extension at hip. There is a synergism between quads also, especially rectus femoris. Note also that these hamstrings directly relate pelvic movement and position to the knee. Group also includes adductor magnus, an accessory extensor of the hip.
Note all these muscles above attach to the pelvis and are there essentially to operate the leg to transport and support the trunk. It’s a lot of muscle with a lot of complex, three-dimensional actions that require robust bone to assist strength of robust muscle.
EVEN MORE PELVIC MUSCLES
Now we look at what we didn't cover last month: an array of smaller pelvis-to-femur muscles, and those of the pelvic floor.
Muscles that assist rotation of the femur
Muscles that Stabilize the Hip
The transverse pelvic/femoral muscles are the muscles of apposition of the hip (they put the femur head/ball in the acetabulum /socket):
gluteus minimus and medius
On the other hand, the longitudinal muscles like
the adductors, especially the long ones
tend to push and loosen the femoral head in an upward direction.
Make a note of this last part: Adducting the leg does not stabilize the hip joint, but is more likely to destabilize it. We tell those who have had hip replacements not to cross the legs (an adduction action) precisely because it will lever the femur laterally away from the socket. Hip replacement folks must not cross the legs standing in Garudasana or sitting in Ardha Matsyendrasana. They must use the piriformis, obturator externus, and the gluteus medius and minimus – the outer hip – to do the work.
These transverse muscles are also part of the structure that supports and helps to lift the pelvic floor, literally keeping your innards from falling or leaking out.
So we like people with weakness and misalignment in the hip joints to work in tadasana with the feet apart at first, so the leg is in an advantageous position and the hip joint and pelvic musculature is relatively stable and balanced.
Pelvic Floor Muscles:
Levator ani, iliococcygeal portion (lateral-medial fibers)
Obturator internus anterior-posterior fibers, lateral border of pelvic floor
Levator ani, pubococcygeal portion (anterior-posterior fibers)
From the top Posteriorly:
Intermediate plane of SI ligaments (5 in number) going from iliac crest to S-1 through S-4.
Anterior plane of SI ligaments going from the posterior edge of the iliac bone to the articular tubercules of the sacrum.
The sacrospinous and sacrotuberous ligaments run from the lower pelvis—the ischial spine to the lateral border of the sacrum and coccyx. These ligaments frame the greater sciatic foramen (passageway) allowing exit of the piriformis muscle, and the lesser sciatic foramen through which passes the tendon of the obturator internus.
Anterior sacroiliac ligaments, one superior and one inferior.
These ligaments wrap (the lines of force actually spiral) around the SI joint structure and run oblique courses, to stabilize the sacrum and ilii in almost all ranges of movement: rotational, anterior-posterior, lateral and vertical. But it can still move in all those directions. The forces at work on the pelvis are enormous.
A SPECIAL JOINT MOVEMENT UNIQUE TO THE SACRUM
Nutation and counternutation:
The movement of the sacrum in relation to the ilii in forward and backward extensions.
Nutation is the forward-tipping of the sacrum around the axis of the SI joint. When this forward tipping occurs, the ilii broaden at their inferior ends and narrow at their superior ends.
Counternutation is involved in backward bending or spinal extension actions. As the pelvis moves in a backbend shape the top of the sacrum moves posteriorly and the tailbone moves anteriorly. This causes the anterior superior ilii to widen away from each other, and the buttock bones to narrow closer to each other.
We will approach the trunk muscles attached to the pelvis in another section. This is certainly plenty as it is.
An Asana Class to Observe the Pelvis
( Skip the poses you are unable to do, but keep the sequence otherwise in this order.)
Make this practice one where you focus your attention on the pelvis and legs, how every part of the leg and foot—including bones, muscle and connective tissues not directly attached to the pelvis—directly influences the position and mobility of the pelvis. Notice how even small position and activation changes immediately register in the pelvis, and from there throughout the rest of the body. Learn to be sensitive to the nuance of leg movement and action. It makes all the difference.]
Adho mukha virasana
Samasthiti (feet hip width or at least apart) and tadasana (feet joined)
Adho mukha svanasana
Hasta padasana, Parsva hasta padasana
Parivrtta parsvakonasana, kneeling on back knee to make the rotation of the spine easier and to make the leg actions more tangible and balance less of an issue,
then straightening the back leg.
Dandasana lift hips and abdomen up as in Tolasana, but leave the feet on the floor.
Adho mukha vrksasana as possible, including kicking up with two legs, bent or straight
Variations as possible: eka pada, parsvaikapada, baddha konasana, urdhva padmasana
EITHER A FORWARD BEND SEGMENT (or see below, a backbending segment):
Parsva upavistha konasana, both upright and folded over L and R legs
Parivrtta upavistha kona with chair or on floor
Padmasana or what is possible in this way, including Siddhasana
Paschimottanasana, lifting a concave spine up, and then extending forward in full pose
OR A BACK BENDING SEGMENT:
Chair dwi pada viparita dandasana, first knees bent and then legs straight
Chair backbend variations as possible
Urdhva dhanurasana pushing up as possible
Urdhva dhanurasana walking feet in as much as possible
Urdhva dhanura pushing up hands on floor, feet on the edge of a chair for high pelvis lift and lovely open lines of extension in bone, muscle and organs. Note: extra strong pose. Arm strength required for this one.
Adho mukha svanasana to normalize the spine after many backbends.
Eka pada Sarvangasana
Urdhva Padmasana in sarvangasana, or what is possible in this way, including strapping the feet/knees in urdhva swastikasana.
Setu bandha sarvangasana knees bent with hips on block or legs straight, as possible. Be easy with this; it’s for recovery, balancing, and cooling, not more backbends.
Supta baddha konasana
Soft bharadvajasana without clasp
Savasana knees bent, then knees straight full pose