Core, Pelvis, and Midsection by Ken Blank

The psoas may be the body's most essential muscle. It is the only muscle in the body that connects the legs to the upper body. The psoas is worked with core building exercises in fitness classes and brings balanced muscular action to the core, pelvis, and midsection.

There are two psoas muscles, one on each side. Each originates on the side of the spine from the 12th thoracic vertebrae to the 5th lumbar vertebrae. The psaos runs thru the pelvis, inserting on the lesser trochanter (bony ridges on the upper, inner femur).     

The psoas is a postural muscle, acting as a hip flexor, shortening when lifting the knee and lengthening when extending the hip.  A short, tight psoas can cause (1) pain in the lower back or hip and (2) the thoracic and cervical spine to pull forward and down, making a yoga practice uncomfortable and difficult.  A healthy psoas is strong and lengthened, allowing the whole body to open. 

The psoas can be visualized as having two sections, one from the lesser trochanter up to the 5th lumbar vertebrae and the other from the 12th thoracic vertebrae down to the 5th lumbar vertebrae. Because the psoas is a postural muscle it must be eccentrically lengthened. (For a discussion of concentric and eccentric contractions see blog #3, An Alignment Principle to Balance Muscular Action.)  To eccentrically lengthen the bottom portion of the psoas, concentrically engage the glutes, the muscles at the base of the pelvis, and the lower abdominals—in that order. To eccentrically lengthen the upper psoas, concentrically engage the upper abdominals and the obliques (muscles on the side of the waist), then the deeper transverse abdominis. (To feel the action of the transverse abdominis, pretend to suck on a straw.) Because the psoas naturally contracts as it lengthens (an eccentric contraction), engaging the opposing muscle groups (muscles surrounding the pelvis and waist) as described above will  balance the muscular action in the core, pelvis, and midsection.

The Quadratus Lumborum (QL) is another postural muscle. The QL inserts on the back body at the bottom of the 12th rib and originates on the top of the pelvis. It runs parallel to the upper portion of the psoas. If the QL is short and tight, it tends to pull the back of the rib cage down. 

The QL opposes the same muscles as the upper portion of the psoas. The actions taken to eccentrically lengthen the psoas will also eccentrically lengthen the QL.  Therefore, if the pelvic muscles and the muscles surrounding the waist are concentrically engaged, the psoas and quadratus lumborum will eccentrically lengthen.  These engagements can be applied to any yoga pose to balance the muscular action of the core, pelvis, and midsection.


Stay Tuned! Next Blog: Shoulders

Balanced Muscular Action of the Thigh by Ken Blank

The thigh, located between the hip (pelvis) and the knee, contains a single bone, the femur, the largest bone in the body. The femur articulates (forms a joint) with the tibia (main lower leg bone), the fibula (supporting lower leg bone), and the patella (knee cap) to form a hinge joint.  The head of the femur articulates with the pelvis to form a ball and socket joint.

The main muscle groups of the thigh are adductors (inner thigh), quadriceps (front of thigh), and hamstrings (back of thigh). The muscles of the thigh can have their origin and insertion on the femur, their origin on the femur and their insertion on the tibia or fibula, or their origin on the pelvis and their insertion on the femur. (For a definition of origin and insertion see blog #3.) Thus, the action of the thigh muscles affect the pelvis above and the knee or lower leg bones below. 

All of the adductors (five muscles on the inner thigh) are phasic and all of the hamstrings (three muscles on the back of the thigh) are postural. The quadiceps (four muscles on the front of the thigh) are composed of three phasic and one postural muscle. For a discussion of phasic and postural muscles see blog #2.  

To bring balanced muscular action to the thigh it is necessary to isolate the engagements of the adductors, quadriceps, and hamstrings.

Example #1, Isolating the Adductors: Standing with your feet parallel and hip width apart, isometrically draw your feet towards one another. 

Example #2, Isolating the Hamstrings: Continuing from example #1, engage the hamstrings and lengthen from the sit bone to the top of the lower leg bones.

Example #3, Isolating a Quadricep: Other than the vastus medialis (just above the knee on the inner thigh,) it is difficult to isolate the actions of the other three quadriceps because one is postural and the others phasic. To engage the vastus medialis, slightly bend your knees.  

To balance the muscular action of any area of the body, concentrically engage a phasic muscle and then eccentrically lengthen an opposing postural muscle.  For the thigh, concentrically engage both the vastus medialis (just above the knee on the inner thigh) and the adductors (inner thigh) and then eccentrically lengthen the hamstrings. As an added benefit, engaging the vastus medialis stabilizes the patella (knee cap.)     

To balance the muscular action of the thigh while doing a forward bend (Uttanasana):

1. Stand with feet parallel and hip width apart.

2. Slightly bend the knees to make it easier to isolate the vastus medialis.

3. Engage the vastus medialis. 

4. Concentrically engage the adductors from just above the knee to the top of the thigh (from insertion to origin)

5. Straighten your knees and eccentrically lengthen the hamstrings from the sit bones to the top of the lower leg bones (origin to insertion).

6. Maintaining these actions and keeping the upper body anatomically neutral, fold forward from the ball and socket joint at the hip. As you fold forward continue to engage the adductors concentrically and to lengthen the hamstrings eccentrically.

These thigh actions can be applied to any yoga pose. At first, putting your mind in the muscle may be all that is accomplished. Over time the body will learn to isolate these actions and balance the strength and flexibility of the thigh muscles.  As the body becomes more balanced, ligaments and tendons will also become stronger and more supple.


Stay Tuned! Next Blog: Pelvis, Midsection and Core

An Alignment Principle to Balance Muscular Action with Ken Blank

Blog #1("Balanced Muscular Action") discussed how the action of a postural muscle against its unbalanced opposing phasic muscle can cause such problems as postural dysfunction, reduced range of motion, and joint pain. Blog #2("Postural and Phasic Muscles") addressed how certain muscles tend to be tight and strong(postural) while others tend to be loose and weak(phasic.)  This blog will introduce a principle to align each section of the body to prevent or to reverse problems caused by muscle imbalance.

Each muscle is anchored in two places, its origin and its insertion. The origin is the part of the muscle closest to the center of the body.  The insertion is the part of the muscle farthest away from the center of the body. As an example the part of the bicep closest to the elbow is the insertion and the part of the bicep closest to the shoulder is the origin.  A muscle contracts moving from insertion to origin. It lengthens moving from origin to insertion.

There are two types of muscle engagements, concentric and eccentric. A concentric contraction strengthens a muscle from insertion to origin. An eccentric engagement strengthens a muscle from origin to insertion.  An example of of a concentric contraction is bending the elbow to contract the bicep by  muscular engagement. Maintaining that muscular engagement as the elbow is straightened is an eccentric lengthening. When the elbow is bent the bicep engages from insertion to origin. When the elbow is straightened the bicep lengthens from origin to insertion. 

The Alignment Principle: Concentrically engage a phasic muscle. Then eccentrically lengthen an opposing postural muscle.  

Example: The tricep opposes the bicep. The tricep tends to be a phasic muscle and the bicep tends to be a postural muscle. With the arm straight, concentrically engage the tricep from insertion(elbow) to origin(shoulder.) Then eccentrically(maintaining engagement) lengthen the bicep from origin(shoulder) to insertion(elbow.)  

If this principle is applied section by section, the entire body can be aligned. Alignment can prevent or reverse joint problems in the knee, hip, shoulder, foot, low back, upper back, elbow, or neck. 

Stay Tuned! Next blog: The thigh, hamstrings, quads, and adductors

postural & phasic muscles with ken blank

Muscles are either postural or phasic. Postural muscles are mainly slow-twitch. Tight and short, they maintain our posture and support our endurance.  Phasic Muscles are mostly fast-twitch. They support movement and fine motor skills but tire and stretch more easily than postural muscles.

Postural and phasic muscles work together in pairs. Typically, the (agonist) postural muscle tightens while the opposing (antagonist) phasic muscle stretches.  

Four Examples of Postural Muscles and Opposing Phasic Muscles

Postural:  Pectoral Major (Chest), Psoas(Core Muscle), Bicep, Hamstrings(Back of Thigh)

Phasic:  Rhomboids(Back between Shoulder Blades), Abdominal Muscles, Tricep, Quadriceps(Front of Thigh

Have you ever noticed someone working their pectorals on a bench press machine but not exercising their rhomboids?  If the pectorals are too strong relative to the rhomboids, one or both shoulders may pull forward and risk injury to the shoulder joint. Do you know people who strengthen their core but don't work their abdominals? This imbalanced exercise risks injury to the lower back because short, tight psoas can flatten the lower back and cause a sacral misalignment. (The sacrum is a triangular bone just below the bottom vertebrae.)    

Building too much relative strength in certain muscles by emphasizing or neglecting one element of a pair can lead to muscular skeletal imbalance or joint instability.  

Our muscles do not act in isolation. If one is out of balance (misaligned) another will react to keep the body in balance. The body's reaction to misalignment can involve multiple muscles with eventual difficulties such as knee pain, shoulder pain, poor posture, scoliosis, and bunions. Prevention and treatment may be as simple as a yoga practice with a teacher knowledgeable in alignment. Particularly, as we age, a consistent balanced yoga practice becomes vitally important to maintain good health. 

Next Blog Focus:  Alignment Principle that Promotes Balanced Action



Balanced Muscular Action with Ken Blank

Introduction to Postural Yoga

As your yoga practice becomes more nuanced, you may begin to notice certain dominant patterns or “natural tendencies” such as feet turning in or out slightly, shoulders rolling in or sagging, or knee caps not facing forward.  If not corrected, these postural dysfunctions can become more pronounced as we age and can limit our range of motion, possibly to the point of needing surgery such as knee replacement, hip replacement, or rotator cuff repair.

The questions become What causes these misalignments? and How do we fix them?

The Cause:  

Research by Dr. Vladmir Janda in the 1970s showed that the problem is muscle imbalance.  Each muscle has an opposing muscle. If one is too strong relative to the other, a joint can be pulled out of alignment and an injury may result.  One of the first yoga principles taught to me was balanced action. The muscular actions of the body should be balanced front to back, side to side, and top to bottom.  In other words, the agonist (muscle that takes an action) should be balanced against its antagonist (muscle that opposes that action).  As an example, the bicep opposes the tricep.  If the bicep is too strong relative to the tricep, it may be difficult to straighten the elbow. If the tricep is too strong relative to the bicep, the elbow may extend too far. 

The Fix:  

Dr. Janda's research found that certain muscles in the body tended to be tight and strong (Postural Muscles) while  others tend to be weak (Phasic Muscles). Over time the postural muscles will overpower the opposing phasic muscles and cause potential  joint problems. A yoga practice that encourages balanced muscular action is good for both prevention and cure of these issues. 


About Ken:  

Ken has been teaching yoga since 2003. He evolved into his yoga practice after teaching karate for 16 years, earning a 4th degree Black Belt. He has learned through his varied experience that yoga is the source of many other physical, intellectual and spiritual disciplines. Ken has the ability to clearly and simply explain complex information in an understandable format. Helping students connect with the bigger energy to feel the flow of Prana, Chi or Ki has always been his primary focus. 

Be sure to look for Ken's next blog: 

1.  Identifying Postural and Phasic muscles

2.  The basic Postural Yoga alignment Principle