“. . . according to the Yoga Sutra (3.1), the term [Bandha] refers to the ‘binding’ of consciousness to a particular object or locus (desha), which is the very essence of concentration.”
Georg Feuerstein

Thursday, March 26, 2015

Stretching, Age and Your Down Dog

As a dog lover, I’m not alone in believing these creatures have important knowledge to pass along to us humans. With this in mind, I want to discuss how aging affects your body and bring to your attention some recent evidence from the scientific literature on how stretching--and Downward Dog--can help.

First, let’s take a look at reciprocal inhibition…

Reciprocal inhibition is a biomechanical and physiological process whereby when we contract a muscle on one side of a joint, the muscle on the other side is inhibited from contracting. This takes place to varying degrees throughout the range of motion of a joint and enables us to do things like walking. For example, when you contract your tibialis anterior to dorsiflex your foot while walking, you automatically inhibit the calf muscles. This helps to prevent catching your toes.

Reciprocal inhibition is controlled and regulated at the level of the spinal cord level and also the brain. Of course, as we reach the ends of range of motion of a joint, a process known as co-contraction kicks in to stabilize the articulation, thus modulating the inhibitory effect of the contracting muscle on its antagonist. In other words, we are not Gumby. (Most folks know this implicitly, but I point it out here to correct some confusing info from recent blogs on the subject of stretching and yoga). Figure 1 illustrates the agonist/antagonist pairs for the forward bend Paschimottanasana and the backbend Setu bandhasana.

Figure 1: Agonist/Antagonist pairs in Paschimottanasana and active Setu bandhasana.

What can happen as we age…

Scientific studies have demonstrated that reciprocal inhibition diminishes as we age (and also in certain disease processes). This is particularly important for activities such as walking. For example, if the tibialis anterior does not efficiently inhibit the gastroc/soleus muscles of the calf, the person tends to catch their toes, stumble and fall. If that weren't bad enough, our bones also weaken with age, so falls can lead to fractures--especially of the hip. This puts the person in a hospital under the care of an orthopedic surgeon as so on…(a story I know all too well). So, methods or techniques that improve reciprocal inhibition could potentially benefit us as we age.

How stretching can help…

Recent scientific evidence has shown that stretching can increase reciprocal inhibition between antagonist muscles. For this study, the authors investigated the effect of stretching on reciprocal inhibition between the tibialis anterior and the gastroc/soleus complex. They stated:

“In conclusion, we have found that 3 wk of twice-daily, static plantar flexor stretching resulted in a significant increase in RI, measured in soleus and gastrocnemius during voluntary, tonic dorsiflexion contractions.” (The full article is linked below in the references)

These are some of the same muscles we work with in Downward Dog. Thus, regular practice of this pose may help maintain reciprocal inhibition between the tibialis anterior and the calf muscles. For a tip on how to make this pose more efficient, take a read through “A Tip to Help You Lower Your Heels In Downward Dog." This blog uses active stretching to improve flexibility of the gastroc/soleus muscle complex. I received a lot of positive feedback on it, so give it a go.

Figure 2: The tibialis anterior as agonist and gastroc soleus as antagonist in Down Dog pose.

On Active Stretching…

In active stretching, one improves muscle flexibility by contracting the opposing muscle group while stretching the target muscle. In the case of the hamstrings, this means engaging the quadriceps during the stretch. Shirley Sahrmann, PhD (Professor of Physiotherapy at Washington University School of Medicine) and others have advocated active stretching as a means of increasing muscle flexibility. It improves flexibility of the muscles on one side of the joint while improving strength and function of the muscles on the other side.

A recent article from the medical literature compared active vs. passive stretching of the hamstring muscles. The authors stated:

“Such an active technique is based on reciprocal inhibition between agonistic and antagonistic muscles.”

And concluded:

“Active stretching produced the greater gain in the AKER test, and the gain was almost completely maintained 4 weeks after the end of the training, which was not seen with the passive stretching group. Active stretching was more time efficient compared with the static stretching and needed a lower compliance to produce effects on flexibility.” (AKER=active knee extension range of motion)

This makes sense to me from a yoga perspective as well--keeping in mind that there are many different ways to climb the mountain. Improving muscle flexibility is only one of the functions of asanas. Active stretching, among other benefits, improves your mind/body connection, alignment of your joints and your mental focus. Improved focus in turn helps to identify and correct imbalances. Click here to read more on the subject of muscle imbalances.

Figure 3: An agonist/antagonist pair in Warrior I (gluteus maximus and illiopsoas).

Figure 4 shows a couple of page spreads from our Yoga Mat Companion book series, illustrating a step-wise approach to working with muscle engagement in the poses.

An excerpt from "Yoga Mat Companion 1 - Vinyasa Flow and Standing Poses".

An excerpt from "Yoga Mat Companion 2 - Hip Openers and Forward Bends".

NB: Evidence based medicine ranks publications and studies according to “levels of evidence”. Level I studies are considered to be more reliable, and are based on randomized controlled trials. Level VII evidence, on the other hand, is essentially an opinion, with variable reliability depending on the source and their actual expertise. The study on active vs. passive stretching I referenced above was a randomized controlled trial (RCT), and is thus Level I(b) evidence.

Thanks for checking in! Click here for more information on combining modern Western science and your yoga. Hope to see you soon.


Ray and Chris

  1. Lavoie BA, Devanne H, Capaday C. “Differential control of reciprocal inhibition during walking versus postural and voluntary motor tasks in humans.” J Neurophysiol. 1997 Jul;78(1):429-38.
  2. Hortobágyi T, del Olmo MF, Rothwell JC. “Age reduces cortical reciprocal inhibition in humans.” Exp Brain Res. 2006 May;171(3):322-9.
  3. S. Meunier , S. Pol , J. L. Houeto , M. Vidailhet “Abnormal reciprocal inhibition between antagonist muscles in Parkinson's disease” Brain. 2000 May;123 ( Pt 5):1017-26.
  4. A. J. Blazevich , A. D. Kay , C. Waugh , F. Fath , S. Miller , D. Cannavan “Plantarflexor stretch training increases reciprocal inhibition measured during voluntary dorsiflexion” Journal of Neurophysiology Published 1 January 2012 Vol. 107 no. 1, 250-256.
  5. Meroni R, Cerri CG, Lanzarini C, Barindelli G, Morte GD, Gessaga V, Cesana GC, De Vito G. “Comparison of active stretching technique and static stretching technique on hamstring flexibility.” Clin J Sport Med. 2010 Jan;20(1):8-14.

Friday, December 19, 2014

Connect Your Feet to Your Shoulders in Side Forearm Plank Pose

Side forearm plank is another awesome pose to strengthen your core while protecting your wrists. You do this one by placing your forearm on the mat and attempting to drag it towards your feet, while engaging the core muscles on your sides to stabilize the lumbar pelvic complex. Keep your supporting arm (the humerus bone) straight up and down (at a right angle to the floor). This way the passive strength of the bone aids to support your body weight. Click here for more on this concept in Vasisthasana.

Figure 1: Side Forearm Plank Preparatory Pose

Begin by stabilizing the shoulders. Do this by attempting to externally rotate your forearm on the mat. At the same time, attempt to internally rotate your forearm on the mat as well. It’s a bit like a windshield wiper that’s fixed in place. This cue “co-activates” the infraspinatus and teres minor (external rotation) and the subscapularis (internal rotation) muscles of your rotator cuff. Feel how this stabilizes your shoulder. Folks that are new to this pose can use the preparatory version to work with this cue. Figure 1 shows the prep pose and Figure 2 illustrates the action of the forearms.

Figure 2: This illustrates the cue for co-activating the external and internal shoulder rotators (the infraspinatus, teres minor and subscapularis of the rotator cuff).

Next, press the edge of your lower side foot into the mat and gently draw it upwards toward the shin to “evert” your foot. These cues activate a series of muscles—including the “lateral subsystem”--to connect your shoulders and legs to your core. Figure 3 shows the cue for attempting to drag the forearm and the feet towards each other (while engaging the side abs).

Now let’s check out the myofascial connections in side forearm plank. When you press the side of your foot into the mat, you activate the peroneus muscles as well as the abductor muscles up at your hip (the TFL and gluteus medius). These muscles have a fascial connection to your abs, specifically the external oblique (which attaches to the rim of the pelvis). The external oblique connects to your shoulders via the serratus anterior muscle. The serratus anterior is a scapular stabilizer that works in concert with the rotator cuff. So the whole operation helps to integrate your feet, legs, pelvis and lumbar--all the way up to the shoulders.

Figure 3: This illustrates the cue of everting the lower foot and dragging the elbow towards it. It also shows the deep longitudinal subsystem.

So let’s talk about the deep longitudinal subsystem…

Your deep longitudinal subsystem is made up of the peroneus longus muscle (on the outside of your lower leg), the biceps femoris of your hamstrings and your sacrotuberous ligament (up in the pelvis), the thoracolumbar fascia and the erector spinae muscles (in your back). The biceps femoris creates a link between the lower extremities and the trunk via the sacrotuberous ligament. This ligament helps to transmit force across your sacrum, and, via the thoracolumbar fascia on up the trunk to your deep back muscles. Check Figure 3 for a color coded illustration of this connection. Click here to see this connection in the lower legs in Reverse Pigeon Pose.

This subsystem is part of the global movement system and is thought to be important in force transmission between your trunk and the ground—as in walking. We’ll have more posts on the other subsystems and how to work with them in yoga soon. Click here to see how the abductor muscles of the hip work in your poses. Click here to learn more about the thoracolumbar fascia and its importance in yoga.

Figure 4 shows the myofascial connection between the external oblique muscle (of the abs) and the serratus anterior of the shoulder girdle.

Figure 4: This illustrates the myofascial connection between the external oblique muscle of the abdomen and the serratus anterior of the shoulder girdle.

Thanks for checking in! Click here to browse through our books by clicking the links on the right. These books have lots of practical cues with key info on anatomic sequencing to integrate into your practice!


Ray and Chris

Friday, June 6, 2014

The Gluteus Medius Muscle in Yoga

Thanks to everyone for your input on Facebook for the “Muscle of the Week”, the gluteus medius. In this blog post we go over the essential anatomy of this muscle and illustrate its action in several yoga poses.

Here’s the anatomy…

The gluteus medius originates on the outer surface of the ilium bone and runs to the greater trochanter of the femur. This muscle acts to stabilize the pelvis when standing on one leg and during walking. The gluteus medius is also a primary abductor of the hip. Its anterior fibers act to synergize flexing and internally rotating the flexed hip; its more posterior fibers synergize extending and externally rotating the extended hip. The gluteus medius is innervated by the superior gluteal nerve, which is formed from nerve roots L4, L5 and S1. Figure 1 illustrates this muscle. 

Figure 1: The gluteus medius muscle with its innervation from the superior gluteal nerve. The gluteus maximus, with the inferior gluteal nerve is shown as a see-through.

Tree pose and other one-legged standing poses help to strengthen the gluteus medius, which is essential for stabilizing the pelvis of the standing leg (figure 2). Click here to read more about the function of the gluteus medius in one-legged asanas in our blog post, “Anatomic Sequencing in Yoga”. Click here to read about the connections of the gluteus medius during gait.

Figure 2: The gluteus medius stabilizing the pelvis in Tree Pose.

Figure 3 illustrates the gluteus medius contracting to help lift the leg in Ardha chandrasana (Half Moon Pose).

Figure 3: The gluteus medius stabilizing the lifted leg in Half Moon Pose.

Engaging the gluteus medius in Downward Dog pose can be used to synergize hip flexion. This muscle also helps to internally rotate the hips, thereby bringing the kneecaps to face forward. The cue for engaging the gluteus medius in Downward Dog Pose is to press the feet into the mat and then attempt to drag them apart. The feet remain constrained on the mat and do not move. However, the abductor muscles, including the gluteus medius, minimus and TFL, engage to refine flexion and rotation of the hips. Click here to read about this in our blog post, “How to Use Nutation to Refine Uttanasana.” Figure 4 illustrates how to work with the gluteus medius and minimus to refine Downward Dog Pose.

Figure 4: Engaging the gluteus medius and minims in Downward Dog Pose.

Figure 5 illustrates the gluteus medius synergizing hip extension in Purvottanasana.

Figure 5: Engaging the gluteus medius to synergize hip extension in Purvottanasana.

Finally, figure 6 illustrates stretching the gluteus medius in Garudasana.

Figure 6: Stretching the gluteus medius in Garudasana.

Many thanks for all of your feedback on stretching the gluteus medius in last weeks “Muscle of the Week” on Facebook. Check back soon for the next one…

Feel free to browse through The Key Muscles of Yoga and Key Poses of Yoga by clicking here.The Yoga Mat Companion Series gives you step-by-step anatomic sequencing for all of the major asanas, with a variety preparatory poses as well. Use these books to design your classes and optimize your practice. We’re also pleased to announce that all of our books are now available in digital format for Kindle, iPad and other digital devices. Click here to learn more…

Thanks for stopping by The Daily Bandha. Stay tuned for our next post when I'll present another subject on combining science and yoga. Also, we greatly appreciate when you share us on Facebook, Twitter and Google Plus.


Ray and Chris

Monday, June 2, 2014

The Rectus Femoris Muscle in Yoga

In this blog post we examine the rectus femoris muscle and its relation to yoga poses, beginning with an overview of the muscle and how it stretches. We conclude with some interesting synergy that can occur between the rectus femoris and the gluteus maximus in poses where both the hip and knee are extending, such as Warrior I.

Here’s the anatomy…

The rectus femoris is one of the four heads of the quadriceps muscle. It runs from the anterior inferior iliac spine to the quadriceps tendon, which attaches to the patella or knee cap. The patella then attaches to the tibial tubercle via the patellar tendon. The rectus femoris thus crosses both the hip and the knee, making it a bi-articular muscle. Note that the other three heads of the quadriceps muscle only cross the knee joint and are mono-articular (figure 1).

Figure 1: The rectus femoris muscle with its origin and insertion.

The rectus femoris combines with the rest of the quadriceps to extend the knee joint. It also acts as a synergist of hip flexion and has increased activity with abduction and external rotation of the hip joint. Figure 2 illustrates this in Supta padangustasana (performed with the leg abducted). Click here to learn more about the relationship between the quadriceps and the pelvis in our blog post, “Preventative Strategies for Lower Back Strains in Yoga.”

Figure 2: The rectus femoris contracting to flex the hip and extend the knee in Supta padangustasana.

Stretching the rectus femoris is best accomplished in poses that combine hip extension and knee flexion. Poses like Virasana (with the hips flexing) are good for stretching the other heads of the quadriceps, however, a reclining variation is necessary to lengthen the rectus femoris. Figure 3 illustrates two poses that stretch this muscle.

Figure 3: Stretching the rectus femoris by extending the hip and flexing the knee.

Finally, figure 4 illustrates the “antagonist/synergist” relationship between the rectus femoris and the gluteus maximus in poses like Warrior I. The gluteus maximus is a hip extensor and, thus, an antagonist of the rectus femoris for this action. If the foot is fixed on the mat, contracting the gluteus maximus tilts the pelvis as shown (closed chain action). Tilting the pelvis back and down creates a pull on the rectus femoris, which is transmitted to the knee joint, leading to more efficient knee extension. In this manner, the gluteus maximus is an indirect synergist of knee extension.

Figure 4: The antagonist/synergist relationship of the gluteus maximus to the rectus femoris. 

Many thanks for all of your feedback on stretching the rectus femoris in last weeks “Muscle of the Week” on Facebook. Check in tomorrow for the next one…

Feel free to browse through The Key Muscles of Yoga and Key Poses of Yoga by clicking here.The Yoga Mat Companion Series gives you step-by-step anatomic sequencing for all of the major asanas, with a variety preparatory poses as well. Use these books to design your classes and optimize your practice. We’re also pleased to announce that all of our books are now available in digital format for Kindle and other devices. Click here to learn more…
Click here to browse through all of our books.

Thanks for stopping by The Daily Bandha. Stay tuned for our next post when I'll present another subject on combining science and yoga. Also, we greatly appreciate when you share us on Facebook, Twitter and Google Plus.


Ray and Chris

Monday, May 26, 2014

The Gastrocnemius/Soleus Complex in Yoga

Big Thanks to everyone for your comments on Facebook for our “Muscle of the Week: The Soleus.” In this blog post we take a look at this muscle, its connection to the gastrocnemius and its relationship to practicing yoga.

Here's the anatomy…

The gastrocnemius and soleus muscles form the triceps surae or gastrocnemius/soleus complex. The soleus muscle originates from the head and neck of the fibula bone and, via a tendinous arch, the soleal line at the back of the tibia bone. The gastrocnemius has two heads; one originates from the medial epicondyle of the femur and the other from the lateral epicondyle. The soleus and gastrocnemius attach to the calcaneus (heel bone) via the Achilles tendon (figure 1).

Figure 1: The gastrocnemius and soleus muscles.

Both muscles act to flex the ankle and invert the subtalar joint. The gastrocnemius, because it crosses the knee, also acts as a knee flexor. Since the two muscles act to plantarflex the ankle, dorsiflexing the ankle joint acts to stretch them. Figure 2 illustrates the relationship between these muscles in cross section.

Figure 2: The gastrocnemius and soleus muscles in cross-section.

As B. W-B. pointed out in her Facebook comment on the soleus, “these muscles help to propel blood and fluids back up out of the legs for proper circulation of your legs.” This is because muscle contraction augments the flow of blood and lymphatic fluid towards the heart via a system of one-way valves within the vessels (figure 3). I discuss this concept in greater detail in a previous blog post (click here to learn more).

Figure 3: One way valves in veins.

In her Facebook comment, A. K. A. recommends placing a slight bend in the knee during dog pose to release the gastrocnemius and focus the stretch more deeply on the soleus muscle. I found this to be helpful as well.

You can also release the gastrocnemius with a series of stretches in Downward Dog pose.  Our blog post on Hanumanasana illustrates the effect of several short duration (<30 seconds) stretches on muscle length, with some links to the biomechanical literature. Finally, engaging antagonist muscles aids to lengthen muscles in a stretch through reciprocal inhibition. Figure 4 illustrates sequentially releasing the gastroc by bending the knee, using the hands to dorsiflex the ankle and then engaging the quads to straighten the knee. A similar sequence can be applied to Downward Dog. Click here for a tip on using reciprocal inhibition to aid in lowering the heels in Down Dog.

Figure 4: 1) bend the knee to release the gastroc; 2) dorsiflex the ankle to stretch the soleus; 3) contract the quadriceps to extend the knee and stretch the gastroc.

The Silfverskiöld test also illustrates the rationale for increased ankle dorsiflexion with the knee bent. We use this test in orthopedics to differentiate a tight gastrocnemius from an Achilles tendon contracture by dorsiflexing the ankle with the knee straight and then with the knee flexed.  Increased ankle dorsiflexion with the knee bent indicates that the limitation of motion at the ankle is coming from the gastrocnemius.

Finally, figure 5 illustrates the connection between the gastrocnemius/soleus complex and the plantar fascia. Click here to learn more in our blog post, “Plantar Fasciitis, Myofascial Connections and Yoga.”

Figure 5: The plantar fascia and gastroc/soleus complex.

Feel free to browse through our books, The Key Muscles of Yoga and Key Poses of Yoga by clicking here.The Yoga Mat Companion Series gives you step-by-step anatomic sequencing for all of the major asanas, with a variety preparatory poses as well. Use these books to design your classes and optimize your practice. We’re also pleased to announce that all of our books are now available in digital format for Kindle and other devices. Click here to learn more… Feel free to browse through all of our books by clicking here.

Thanks for stopping by The Daily Bandha. Stay tuned for our next post when I'll present another subject on combining science and yoga. Also, we greatly appreciate when you share us on Facebook, Twitter and Google Plus.


Ray and Chris

Wednesday, May 7, 2014

Anatomic Sequencing: Revolved Half Moon Pose

This blog post continues the theme of balancing the pelvis in yoga asanas. Our last post focused on using the adductor magnus to turn the pelvis in Warrior I; this post zooms in on the hip abductors for Revolved Half Moon Pose. 

As I discussed in “Connecting to Your Feet in Yoga”, you can learn a great deal about biomechanics by examining how the body responds to pathological conditions. In that post, I looked at a variation of flat foot deformity, the ligaments and muscles involved and how to work with yoga to strengthen the arches of the feet. Here, I examine what happens with the pelvis when the hip abductors are not functioning properly. Then I illustrate how to use this knowledge to refine asanas like Revolved Triangle and Revolved Half Moon. 

Balancing the pelvis is a key factor in normal gait as well as yoga poses. Conversely, persons with weakness in the hip abductors develop what is known as a “Trendelenberg” gait, where the pelvis tilts up and shifts toward the affected side during the stance phase of walking. A variety of conditions can affect the hip abductors, including hip pain (from arthritis) and injury to the nerve supply of the gluteus medius. 

In medicine, we test the function of the hip abductors by having the patient stand on one leg in the “Trendelberg Test”. When the muscles are competent, they automatically engage to draw the pelvis level; when the muscles are weakened, the pelvis on the standing leg side lifts (while the lifted leg side sags downward). At the same time, the spine curves toward the affected hip, with the shoulder girdle tilting towards that side.  Figure 1 illustrates the Trendelenberg Test. Note how the pelvis tilts and the spine laterally flexes when the gluteus medius does not engage properly.

Figure 1: The Trendeleberg Test; Image on the left illustrates the gluteus medius engaging to stabilize the pelvis.  Image on the right illustrates pelvic tilt and lateral spine flexion with the dysfunctional gluteus medius.

The spine compensating for the tilt of the pelvis is an example of lumbar-pelvic rhythm. Click here to read more on this important subject in our blog post, “Preventative Strategies for Lower Back Strains in Yoga”. Click here to learn more about the muscles involved in one-legged standing in our blog post, “Improving Stability in One Legged Standing Poses.”

Now, let’s look at how we can apply this knowledge to help lift the back leg in Revolved Half Moon Pose…

I begin by training awareness of the abductor muscles (especially the gluteus medius) in Revolved Triangle Pose. The cue for this is to fix the forward foot on the mat and attempt to drag it to the outside, while resisting with the hand. You will note that this helps to bring the pelvis in line with the rest of the body. Figure 2 illustrates the preparatory poses for this asana and Figure 3 illustrates the cue.

Figure 2: Preparatory poses for Revolved Triangle Pose.

Figure 3: Engaging the hip abductors in Revolved Triangle Pose.

Next, I use sequential muscular engagement to lift the back leg in Revolved Half Moon Pose, beginning with the hip abductors of the standing leg. Engaging these muscles acts to lift, rotate and stabilize the pelvis on the side of the lifted leg (in a fashion similar to what we learned with the Trendelenberg Test). Then I engage the muscles that lift the leg itself, including the gluteus maximus and its synergists of hip extension (the hamstrings and adductor magnus). The gluteus maximus contracts eccentrically.

Finally, I use the quadriceps to straighten the knee. Figure 4 illustrates the preparatory poses for Revolved Half Moon Pose. Figures 5 and 6 illustrate engaging the hip abductors in the standing leg to lift the side of the pelvis for the raised leg. Figure 7 illustrates the final step--engaging the hip extensors and the quadriceps of the raised leg. Work with a chair or block to gain stability if you are new to the pose.

Figure 4: The preparatory poses for Revolved Half Moon Pose.

Figure 5: Engaging the hip abductors to lift the pelvis on the side of the raised leg.

Figure 6: Engaging the hip abductors to lift the pelvis on the side of the raised leg.

Figure 7: Engaging the hip extensors of the raised leg (gluteus maximus, hamstrings, adductor magnus) and knee extensor (quadriceps).

Note that the deep external rotators of the standing leg also facilitate stabilizing the pelvis in Revolved Half Moon Pose. Figure 8 illustrates these muscles.

Figure 8: The deep external rotators stabilizing the pelvis in Revolved Half Moon Pose.

These steps are an example of anatomic sequencing for yoga. Each muscle group is engaged in a specific order to achieve optimal form and stability. The Yoga Mat Companion Series gives you step-by-step anatomic sequencing for all of the major asanas, with a variety preparatory poses as well. Use these books to design your classes and optimize your practice. We’re pleased to announce that all of our books are now available in digital format for Kindle and other devices. Click here to learn more… Feel free to browse through all of our books by clicking here.

Thanks for stopping by The Daily Bandha. Stay tuned for our next post when I'll present another subject on combining science and yoga.  Also, we greatly appreciate when you share us on Facebook, Twitter and Google Plus.


Ray and Chris

Monday, March 10, 2014

Refining the Pelvis in Warrior I

Yoga often happens in millimeters. This means that relatively small adjustments can produce some of the most important openings and energetic shifts. In this blog post, I describe a cue to refine the pelvis in the asana, Warrior I (Virabhadrasana I), concluding with a brief discussion of the biomechanics of this adjustment.

Here’s the cue...

In Warrior I, press the back foot into the mat and attempt to drag it toward the midline (adduction). You will feel the pelvis turn forward to “square” with the front leg. Figures 1 and 2 illustrate this action, with its effect on the pelvis.

Figure 1: Press the foot into the mat and then attempt to drag it toward the midline. This engages the adductor magnus.

Here are the biomechanics of this cue...

In Warrior I, the back leg is in extension. The prime mover muscle for this action is the gluteus maximus. One of the synergists for extending the hip is the adductor magnus muscle. Attempting to drag the foot towards the midline engages this muscle in the pose. The foot remains constrained on the mat and does not actually move, however, the force of contracting the adductor magnus decreases the angle between the femur and the pelvis, as shown. The result is that the pelvis turns (instead of the foot moving). In addition, the hip extends more effectively. All of this produces a unique opening in the front of the pelvis that stretches the hip flexors, including the psoas muscle (figure 3).

Figure 2: This illustrates engaging the adductor magnus by attempting to drag the foot towards the midline. The mat constrains the foot, and the force of contraction turns the pelvis.

Figure 3: This illustrates the flexor muscles of the back hip stretching.

Use this adjustment after “setting” the feet. The technique for this is described in my previous blog post on connecting to your feet in yoga. Click here to read more. These cues can be combined with co-activation of the hip stabilizers for the front leg, as described previously for Warrior II (click here to read more). Finally, “ease into” your movements when working with cues such as this. Build muscular engagement gradually to turn the pelvis; then gradually release it as you come out of the pose.

For many more helpful cues on biomechanics and yoga, feel free to browse through "The Key Muscles and Key Poses of Yoga". Also, see the "Yoga Mat Companion" series, which gives you step-by-step guidelines for applying these cues to all categories of poses. Click here to learn more.


Ray and Chris (illustrator)

Tuesday, December 24, 2013

Healing with Yoga: Piriformis Syndrome

Years ago I developed sciatica as a consequence of a martial arts injury. I had seen a number of doctors who finally diagnosed it as an entrapment syndrome involving the piriformis muscle and the sciatic nerve. I tried, unsuccessfully, all of the conservative methods to treat it, including physical therapy, massage, manipulation—you name it. Finally, it looked like I would either have to live with the pain or have surgery—for which there was no guarantee of success. As it happened, one day I wandered into a yoga class at the Ann Arbor YMCA.

I remember being impressed by how different (and difficult) a yoga class was, even though I was used to hard physical training from playing sports; we were working with the body in ways I had never experienced and using precise movements and muscular engagements I hadn’t seen in other exercise methods. Not only did I feel great after my first class but also, to my surprise, the next day I noticed that my sciatic pain was greatly improved. Putting two and two together, I started going regularly to classes at YMCA (and later, the basement of a church). As long as I went to class, my sciatica no longer bothered me. With this in mind, let’s take a look at piriformis syndrome.

Piriformis Syndrome:

Piriformis syndrome is characterized by buttock and/or hip pain that may radiate into the leg as a form of sciatica. This syndrome is thought to result from spasm of the piriformis which causes irritation of the sciatic nerve as it passes across (or through) the muscle. Spasm in the piriformis can be precipitated by an athletic injury or other trauma. The mainstay of treatment involves stretching the piriformis and its neighboring external hip rotators, with surgery to release the muscle reserved for recalcitrant cases.

Tightness or asymmetries in the piriformis muscle can create rotational pelvic imbalances. This, in turn, can lead to imbalances further up the spinal column, through the process of "joint rhythm". Click here to learn more about lumbar pelvic rhythm in our previous blog post on Preventative Strategies for Lower Back Strains. Below in the links is a reference to an article from the Osteopathic literature addressing this subject in relation to the piriformis muscle.

Figure 1 is an illustration of the relationship of the sciatic nerve to the piriformis muscle. Approximately 80% of the time the nerve passes anterior to the muscle, exiting below the piriformis. The sciatic nerve can also divide above the muscle, with one branch passing through the piriformis and another branch passing anterior. This variation occurs about 14% of the time. Other variations include the undivided nerve passing through the muscle and the divisions passing both anterior and posterior to the piriformis (without penetrating the muscle). Note that the sciatic nerve can penetrate the muscle without ever causing pain or other symptoms (as is usually the case). Persons with this variation may, however, be predisposed to developing piriformis syndrome from an injury.

Various relationships of the sciatic nerve to the piriformis muscle.

Diagnosis of piriformis syndrome is accomplished through a careful history and physical examination as well as radiological studies. The physical exam includes the FAIR test (flexion, adduction, internal rotation of the hip). Click here for an example of this test.

Note that other causes of sciatica must be excluded before making the final diagnosis of piriformis syndrome. These include a herniated disc causing nerve root compression. Similarly, pathology affecting the hip joint must also be excluded. Accordingly, if you have sciatic type pain, be sure to consult a health care practitioner who is appropriately trained and qualified to diagnose and manage such conditions.

To review, when the hip is in a neutral position, the piriformis acts to externally rotate (turn outward), flex and abduct the hip joint. When the hip is flexed beyond about 60 degrees the piriformis becomes an internal rotator and extensor (and remains an abductor). Muscles stretch when we move a joint in the opposite direction of the action of the muscle. Click here for a review of the piriformis muscle, its attachments and action, and the mechanism of Reverse Pigeon Pose (video below).

Figures 2-5 illustrate several yoga poses that stretch the piriformis. Parvritta trikonasana and the rotating version of Supta padangustasana lengthen the muscle by adducting and flexing the hip. Similarly, Parsva bakasana and Marichyasana III adduct and flex the hip joint, thus stretching the muscle (which an extensor and abductor when the hip is flexing).

Figure 2. Piriformis stretching in supta padangusthasana.

Figure 3. Piriformis stretching in Parvritta trikonasana.

Figure 4. Piriformis stretching in Marichyasana III.

Figure 5. Piriformis stretching in Parsva bakasana.

Figure 6. Supported setu bandha - a recovery pose which maintains the piriformis in a relaxed position.

Video 1 demonstrates stretching of the piriformis in Reverse Pigeon Pose. This asana stretches the muscle by externally rotating and flexing the hip.

Video 2 illustrates the technique for using mysofascial connections to protect the knee joint in this pose. Click here for the details of this technique.

Thanks for stopping by. If you would like to learn more about combining modern Western science and yoga, feel free to browse through The Key Muscles and Key Poses of Yoga, as well as the Yoga Mat Companion series by clicking here. Many thanks for your support in sharing us on Facebook, Twitter and Google Plus!


Ray and Chris (illustrations)

  1. Pokorný D, Jahoda D, Veigl D, Pinskerová V, Sosna A. “Topographic variations of the relationship of the sciatic nerve and the piriformis muscle and its relevance to palsy after total hip arthroplasty.” Surg Radiol Anat. 2006 Mar;28(1):88-91.

  2. Boyajian-O'Neill LA, McClain RL, Coleman MK, Thomas PP “Diagnosis and management of piriformis syndrome: an osteopathic approach.” J Am Osteopath Assoc. 2008 Nov;108(11):657-64.

  3. Filler AG, Haynes J, Jordan SE, Prager J, Villablanca JP, Farahani K, McBride DQ, Tsuruda JS, Morisoli B, Batzdorf U, Johnson JP. “Sciatica of nondisc origin and piriformis syndrome: diagnosis by magnetic resonance neurography and interventional magnetic resonance imaging with outcome study of resulting treatment.” J Neurosurg Spine. 2005 Feb;2(2):99-115.
  4. Rodrigue T, Hardy RW. “Diagnosis and treatment of piriformis syndrome.” Neurosurg Clin N Am. 2001 Apr;12(2):311-9.

  5. Papadopoulos EC, Khan SN. “Piriformis syndrome and low back pain: a new classification and review of the literature.” Orthop Clin North Am. 2004 Jan;35(1):65-71.

Friday, December 13, 2013

Preventing Yoga Injuries vs Preventing Yoga, Part III: Joint Mobility, Stability and Proprioception

A central concept in all healing arts is that of correcting imbalances within the body. The principle of re-establishing balance can be found across all cultures from Navajo sand paintings, Ayurveda, Traditional Chinese Medicine to modern allopathy.  And anything with true healing power also has the capacity to cause injury when practiced without balance. For example, joint mobility is beneficial for a number of reasons--provided it is balanced with joint stability. In this blog post I discuss the concept of joint proprioception and its relationship to joint stability and yoga, concluding with a tip for “re-setting” muscular proprioception following hip openers. 

Proprioception refers to the sense of the relative position of neighboring body parts, such as the femoral head within the hip socket (acetabulum) as well as the muscular force utilized in movement of those parts. This is in contradistinction to exteroception, which is the perception of the outside world (like the feeling of the feet on the ground) and interoception, which is the perception of the inside of the body (pain, hunger etc). I look at proprioception as a type of “GPS” for the joints.

Joint position is detected by specialized nerve endings known as “proprioceptors” that are located within the muscles, ligaments and joint capsule and the periosteum (on the surface of the bones). These receptors communicate information about the joints to the brain via the sensory columns of the spinal cord.  Conscious sense of joint position is transmitted to the cerebrum of the brain; unconscious proprioception is communicated to the cerebellum. Figure 1 illustrates this pathway in a cross section of the spinal cord. 

Scientific studies have demonstrated that joint position sense is decreased in persons with osteoarthritis, with the consideration that reduced proprioception may play a role in the development of the disease. Indeed, exercises that improve proprioception have been demonstrated to be effective in the conservative management of osteoarthritis.  

Proprioception is also reduced in persons with joint hypermobility; exercises that improve joint position sense are also effective in reducing symptoms in this population. I suspect that proprioception may be also be a factor in those having joint pain associated with subtle instability (who do not have an identifiable cause for their pain such as arthritis, hypermobility or a structural lesion). Similarly, the diminished performance seen in certain athletes following stretching routines may be related to reduced joint position sense.

I bring this up in relation to yoga because certain individuals experience soreness in their hips following hip opening poses.  Understanding that this pain may be related to decreased proprioception, I have been using a simple technique to re-establish joint position sense following these poses. For example, I worked with several practitioners during the Blue Spirit Intensive who had this type of hip soreness. Following a sequence that led to Full Lotus, we applied the technique, which “resets” the joint position sense in the hips. After the “reset”, these folks noticed that the hip pain they typically felt was gone, with this benefit remaining throughout the day.

This leads me to believe that some of the hip pain experienced by practitioners may be related to a reduction in muscular proprioception after stretching, which persists as a subtle form of instability during other activities following practice. Furthermore, the soreness appears to be relieved by a technique to increase proprioception that involves co-activating the muscles surrounding the hip joint at a midpoint of the joint's range of motion.

Here’s the technique…

Following a hip opening sequence, and before Savasana, I utilize an intermediate version of Warrior II, where the forward knee and hip are not flexing deeply (figure 2). Then I “co-activate” the hip muscles in the forward leg (co-activation involves simultaneously contracting muscles that have opposite actions). The cue for this is to imagine pressing the inside of knee into an immoveable object while at the same time pressing the outside of the knee into a similar object (the knee remains centered and does not move). This engages both the hip adductors and abductors, as well as the internal and external rotators in a position where the joint is in the mid-range of motion. Done properly, this cue should give a feeling of stability in the hip joint.

Since it is a neurological process, this technique does not require strong muscular contraction; I only utilize just enough strength to feel the muscles engage and the hip stabilize. Furthermore, the cue only requires a short duration. I have been using 20 seconds, repeated twice on each side. The effect is a bit like “resetting” a GPS that has gone out of its normal range. Figures 3-5 illustrate the muscle groups involved with the arrows demonstrating the direction of force. Visualization of the muscles helps in this process.

Figure 2: Warrior II intermediate version. I use this for training proprioception.

Figure 3: Co-activating the hip adductors, abductors and rotators in Warrior  II.

Figure 4: Co-activating the hip adductors, abductors and rotators in Warrior  II.

Figure 5: Activating the deep external rotators of the hip in Warrior II.

Thanks for stopping by. We hope that you enjoy this tip on training proprioception of the hip joint. Note that if you have persistent hip pain or other symptoms, be sure to consult a health care provider who is appropriately trained and qualified to manage such conditions. 

If you would like to learn more about anatomy, biomechanics and yoga, feel free to browse through The Key Muscles and Key Poses of Yoga. Also, check out the Yoga Mat Companion series, which contains many examples of co-activation (including the one in this post). Many thanks for your support by sharing us on Facebook, Twitter and Google Plus as well.


Ray and Chris

  1. Wolf JM, Cameron KL, Owens BD. “Impact of joint laxity and hypermobility on the musculoskeletal system.” J Am Acad Orthop Surg. 2011 Aug;19(8):463-71.
  2. Smith TO, Jerman E, Easton V, Bacon H, Armon K, Poland F, Macgregor AJ. “Do people with benign joint hypermobility syndrome (BJHS) have reduced joint proprioception? A systematic review and meta-analysis.” Rheumatol Int. 2013 Nov;33(11):2709-16.
  3. Smith TO, King JJ, Hing CB. “The effectiveness of proprioceptive-based exercise for osteoarthritis of the knee: a systematic review and meta-analysis.” Rheumatol Int. 2012 Nov;32(11):3339-51.
  4. Sahin N, Baskent A, Cakmak A, Salli A, Ugurlu H, Berker E. “Evaluation of knee proprioception and effects of proprioception exercise in patients with benign joint hypermobility syndrome.” Rheumatol Int. 2008 Aug;28(10):995-1000.
  5. Lund H, Juul-Kristensen B, Hansen K, Christensen R, Christensen H, Danneskiold-Samsoe B, Bliddal H. “Movement detection impaired in patients with knee osteoarthritis compared to healthy controls: a cross-sectional case-control study.” J Musculoskelet Neuronal Interact. 2008 Oct-Dec;8(4):391-400.
  6. Sharma L. “Proprioceptive impairment in knee osteoarthritis.” Rheum Dis Clin North Am. 1999 May;25(2):299-314, vi.
  7. Liikavainio T, Lyytinen T, Tyrväinen E, Sipilä S, Arokoski JP. “Physical function and properties of quadriceps femoris muscle in men with knee osteoarthritis.” Arch Phys Med Rehabil. 2008 Nov;89(11):2185-94.
  8. Lauersen JB, Bertelsen DM, Andersen LB. “The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials.” Br J Sports Med. 2013 Oct 7.
  9. Caplan N, Rogers R, Parr MK, Hayes PR. “The effect of proprioceptive neuromuscular facilitation and static stretch training on running mechanics.” J Strength Cond Res. 2009 Jul;23(4):1175-80.
  10. Higgs F, Winter SL. “The effect of a four-week proprioceptive neuromuscular facilitation stretching program on isokinetic torque production.” J Strength Cond Res. 2009 Aug;23(5):1442-7.
  11. Handrakis JP, Southard VN, Abreu JM, Aloisa M, Doyen MR, Echevarria LM, Hwang H, Samuels C, Venegas SA, Douris PC. “Static stretching does not impair performance in active middle-aged adults.” J Strength Cond Res. 2010 Mar;24(3):825-30.
  12. Wu Q, Henry JL. “Functional changes in muscle afferent neurones in an osteoarthritis model: implications for impaired proprioceptive performance.” PLoS One. 2012;7(5): Epub 2012 May 14.
  13. Shu B, Safran MR. “Hip instability: anatomic and clinical considerations of traumatic and atraumatic instability.” Clin Sports Med. 2011 Apr;30(2):349-67.
  14. Smith MV, Sekiya JK. “Hip instability.” Sports Med Arthrosc. 2010 Jun;18(2):108-12.
  15. Holla JF, van der Leeden M, Peter WF, Roorda LD, van der Esch M, Lems WF, Gerritsen M, Voorneman RE, Steultjens MP, Dekker J. “Proprioception, laxity, muscle strength and activity limitations in early symptomatic knee osteoarthritis: results from the CHECK cohort.” J Rehabil Med. 2012 Oct;44(10):862-8.

Tuesday, November 19, 2013

Preventing Yoga Injuries vs Preventing Yoga, Part II: Joint Hypermobility

In this post we discuss labral tears and the condition of joint hypermobility. I also present the case of a specific injury from yoga practice, its biomechanical basis and the steps that can be taken to aid in its prevention.

First, however, let’s look at the concept of association vs causality. Simply put, because some activity is associated with a problem does not mean it caused it. In medicine, when we recognize that an injury is associated with a specific activity we then investigate whether there are factors associated with that activity that could cause the injury. An example would be anterior cruciate ligament (ACL) tears.

A while back, we recognized that ACL tears were approximately five times more common in female athletes compared to males. Thus, investigators sought to identify circumstances that could account for this increased incidence. The risk factor thought to contribute most significantly to the higher rate of ACL ruptures in female athletes related to insufficient neuromuscular control of the knee joint in certain athletes. Accordingly, neuromuscular training regimens were devised that have reduced the incidence of ACL ruptures in this group. This approach to ACL injuries is an example of working with science to decrease the risk of an activity, not the activity itself. With this in mind, let’s look at the potential association of joint hypermobility with yoga injuries.

Joint hypermobility, also known as generalized ligamentous laxity, is a spectrum ranging from mild “loose joints” to systemic pathological conditions such as Ehlers Danlos syndrome (a rare inherited condition that affects the connective tissue throughout the body). “Benign” joint hypermobility, or “double jointedness”, affects between 5% and 15% of the population, with most studies showing this condition to be significantly more common in women vs men. We evaluate the degree of hypermobility using the Beighton criteria, which examines factors such as knee, elbow and thumb hyperextension. Based on these factors, a score is created to quantify whether a person has hypermobility syndrome.

Joint hypermobility affects the capsular and ligamentous stabilizers of the articulations, which are lax. It is associated with an increased incidence of musculoskeletal injuries, including to the labrum of the shoulder and hip joints due to increased translations across the structure. The mainstay of management for ligamentous laxity (hypermobile joints) is physical therapy that is focused on strengthening the muscular stabilizers surrounding a given joint and improving proprioception. Now, let’s look at joint hypermobility in relation to injuries that may be associated with yoga.

Injuries that can be unequivocally directly attributed to practicing yoga, like the one described below, are infrequent (in my clinical experience) simply because yoga practitioners are active people who engage in other pursuits that may also cause injuries (sports, dance etc). Put another way, folks that actually practice yoga are generally not couch potatoes. Further complicating the issue are age related disease processes that can affect the joints whether or not one practices yoga. Nevertheless, we need to watch for associations of injuries with yoga and, where possible, determine their underlying cause, identify subgroups that may be at particular risk, and take steps to minimize those risks. With this in mind, let’s look at a specific injury that was caused during yoga practice, its biomechanical basis and steps that can be taken to aid in prevention.

During the past year I saw one yoga injury that was specifically caused by practicing a pose. This involved an experienced teacher who was demonstrating the “wrong way” to perform Vasisthasana (side plank pose) by having the hand of the supporting arm forward of the shoulder joint instead of directly below the shoulder and at a right angle to the floor. In the process, she experienced a “clunk” in her shoulder, followed by pain. On exam in the clinic, she was found to have joint hypermobility, as quantified by the Beighton criteria. Her MRI demonstrated a tear of the posterior part of the shoulder labrum. Conservative treatment with physical therapy, etc. was not successful in relieving her pain and she required arthroscopic repair of the labrum with tightening of the capsule.

It is worth noting that this teacher had practiced Vasisthasana many times with the hand placed below the shoulder without difficulty. Additionally, on questioning it was clear that she was not actively engaging the muscular stabilizers of the shoulder joint during the demonstration.

Now, let’s look at the mechanism of injury. First, as part of their joint hypermobility, this person had a condition known as “multidirectional shoulder instability”. In patients with this condition, the shoulder capsule and ligaments are lax and thus, do not contribute sufficiently to stability of the joint. As a result, the head of the shoulder can “slide” around on the glenoid (socket) more than usual. This causes increased translational forces across the glenoid labrum. In this particular case, while attempting side plank, she subluxed the head of the humerus over the labrum, tearing it.

Figure 1: Bone structure of the shoulder; Figure 2: Ligaments and capsule; Figure 3: Muscular stabilizers
1-supraspinatus, 2-subscapularis, 3-infraspinatus, 4-triceps, 5-biceps(short head),
6-biceps(long head), 7-deltoid, 8- pectoralis major, 9-pectoralis minor

The three factors that contribute to mobility and stability of the joint are the bone shape, the capsulo-ligamentous structures and the muscles surrounding the articulation. Figure 1 illustrates the structure of the shoulder joint. Composed of a shallow socket and relatively thin capsular and ligamentous supports, this is the most mobile articulation in the body. The muscular stabilizers, including the rotator cuff play an important role in maintaining the congruency of the shoulder joint. When the capsule and ligaments are loose, then the muscles must compensate. This is why we focus on strengthening the muscles in multidirectional shoulder instability. Figures 1, 2 and 3 illustrate the bone structure, capsulo-ligamentous stabilizers and muscular stabilizers respectively.
Figure 4: Vasisthasana illustrating the direction of gravity in variations of hand position.

Looking at the factors that caused this teacher to experience a subluxation with the hand forward of the shoulder we can see that, in this position, the body weight is directed at an angle to the alignment of the arm bones. When the hand is placed below the shoulder, the supporting arm is aligned in a position such that the bones are perpendicular to the direction of gravity. Practicing the pose in this way requires less muscular effort because it uses the inherent passive strength of the bones to aid in supporting the body weight. When the hand is placed forward of the shoulder, greater muscular effort is required to maintain the pose (figure 4).

People with joint hypermobility depend to a greater degree on the muscular stabilizers of the joint. Placing the hand so that the arm is angled against gravity means that these muscles must also work to support the body weight that would be borne, in part, by the bones. You can experience this concept yourself by standing near a wall and leaning against it (figure 5). Then, move the feet a bit further from the wall. Which one requires less muscular effort?

Figure 5: Illustrating using bone alignment vs muscular force.

Figures 6 illustrates Vasisthasana with the supporting muscular stabilizers. I go over a step-wise approach to engaging these muscles and the other core stabilizers of the trunk and legs in Yoga Mat Companion Four (arm balances and inversions).

Figure 6: Muscular stabilizers of the shoulder in Vasisthasana.

Labral Tears in the Hip:

In our most recent blog post we discussed the normal structure and function of the hip labrum. Now let’s discuss labral tears. A number of activities have been associated with this injury including soccer, hockey, golf, ballet, gymnastics, and running. Additionally, a number of specific movements have been associated with labral tears. Pregnancy and childbirth have also been associated with acute tears of the labrum. Even shopping has been associated with injuries to this structure ("supermarket hip"). Other causes of labral tears include ligamentous laxity and abnormalities of the bone. Nevertheless, up to 75% of the time, symptomatic labral tears of the hip are not associated with an identifiable event or cause.

Adding to the complexity is the consideration that labral pathology may be related to the aging process, with up to 96% of cadaver specimens having tears. Furthermore, labral tears do not always cause pain; indeed, a prospective blinded study published in the American Journal of Sports Medicine identified labral tears in 69% of the joints studied in volunteers with no history of injury, pain or other symptoms. Even accounting for false positive mri’s, that is a significant number. Hip injuries and arthritis are among the most intensively investigated areas in medicine today, with new studies being published each month. In this regard, please review the linked references below.

Figure 7: Hip Labral Tear.

One of the known causes of tears of the hip labrum is joint hypermobility. This is also a factor during pregnancy, when hormonal influences cause ligamentous laxity in persons who are not normally hypermobile. Tears of the hip labrum occur in this setting as result of increased translational forces across the labrum from the femoral head. As with hypermobile joints elsewhere in the body, hypermobility in the hips is managed (at least initially) by strengthening the muscular stabilizers that surround the joint. This aids to prevent injuries.

I think this is relevant in light of recent media attention on hip injuries and yoga, particularly since many of those practicing poses that take the hip joints into extreme positions also have hypermobile joints. In my experience, such individuals—who can easily perform extreme movements—often do so without maintaining muscular engagement during extremes of motion. Of particular note is a recent NY Times article that discusses flexibility as a liability for women in yoga. While spending considerable time discussing bone abnormalities (which are more prevalent in men, and were not thought to be a factor in studies on dancers), the NY Times article does not discuss joint hypermobility or the use of muscular stabilization during practice--something that is a cornerstone of injury prevention, especially in persons with high levels of joint mobility. Perhaps a more relevant view of the matter was presented in the Canadian media

Finally, here are a couple of suggestions that I have found to be helpful in my own practice and teaching:

  1. Ease into the end points of poses. Joints adapt to gradual changes much better than abrupt or rapid ones. For example, I deliberately slow down my movement as I near the end point of forward flexion in Uttanasana. This helps to protect the joints and also creates mindfulness in the practice.
  2. Use gentle muscular engagement to stabilize the joints. This is a cornerstone of rehabilitation and injury prevention. Knowledge of the musculoskeletal system and visualization helps in this process.

Note: if you have hip pain or other symptoms (from any activity), be sure to consult a health care professional who is appropriately trained and qualified to diagnose and manage such conditions. Follow their guidelines for your condition.

To learn more about anatomy, biomechanics and yoga, feel free to page through The Key Muscles and Key Poses of Yoga and the Yoga Mat Companion Series. If you would like to learn more about combining modern Western science with the ancient art of yoga, please join us for a week in paradise at our workshop in Bali for a five day intensive on anatomy, biomechanics and therapeutics for Hatha yoga.

Thanks for stopping by. Be sure to tune in this week for our next post. Also, many thanks for your support by sharing us on Facebook, Twitter and Google Plus.


Ray and Chris

  1. Mandelbaum BR, Silvers HJ, Watanabe DS, Knarr JF, Thomas SD, Griffin LY, Kirkendall DT, Garrett W Jr. “Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up.” Am J Sports Med. 2005 Jul;33(7):1003-10.
  2. Wolf JM, Cameron KL, Owens BD. “Impact of joint laxity and hypermobility on the musculoskeletal system.” J Am Acad Orthop Surg. 2011 Aug;19(8):463-71.
  3. Pacey V, Nicholson LL, Adams RD, Munn J, Munns CF. “Generalized joint hypermobility and risk of lower limb joint injury during sport: a systematic review with meta-analysis.Am J Sports Med. 2010 Jul;38(7):1487-97.
  4. Konopinski MD, Jones GJ, Johnson MI. “The effect of hypermobility on the incidence of injuries in elite-level professional soccer players: a cohort study.Am J Sports Med. 2012 Apr;40(4):763-9.
  5. McCormack M, Briggs J, Hakim A, Grahame RJoint laxity and the benign joint hypermobility syndrome in student and professional ballet dancers.J Rheumatol. 2004 Jan;31(1):173-8.
  6. Boykin RE, Anz AW, Bushnell BD, Kocher MS, Stubbs AJ, Philippon MJ. “Hip instability. J Am Acad Orthop Surg. 2011 Jun;19(6):340-9.
  7. Lewis CL, Sahrmann SA. “Acetabular labral tears. Phys Ther. 2006 Jan;86(1):110-21.
  8. Groh MM, Herrera J. “A comprehensive review of hip labral tears. Curr Rev Musculoskelet Med. 2009 Jun;2(2):105-17.
  9. Baker JF, McGuire CM, Mulhall KJ.Acetabular labral tears following pregnancy. Acta Orthop Belg. 2010 Jun;76(3):325-8.
  10. Yamamoto Y, Villar RN, Papavasileiou A. “Supermarket hip: an unusual cause of injury to the hip joint.Arthroscopy. 2008 Apr;24(4):490-3
  11. Register B, Pennock AT, Ho CP, Strickland CD, Lawand A, Philippon MJ. “Prevalence of abnormal hip findings in asymptomatic participants: a prospective, blinded study.Am J Sports Med. 2012 Dec;40(12):2720-4.
  12. Agricola R, Heijboer MP, Roze RH, Reijman M, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Waarsing JH. Pincer deformity does not lead to osteoarthritis of the hip whereas acetabular dysplasia does: acetabular coverage and development of osteoarthritis in a nationwide prospective cohort study (CHECK).Osteoarthritis Cartilage. 2013 Oct;21(10):1514-21.
  13. Leunig M, Jüni P, Werlen S, Limacher A, Nüesch E, Pfirrmann CW, Trelle S, Odermatt A, Hofstetter W, Ganz R, Reichenbach S. “Prevalence of cam and pincer-type deformities on hip MRI in an asymptomatic young Swiss female population: a cross-sectional study.Osteoarthritis Cartilage. 2013 Apr;21(4):544-50.
  14. Agricola R, Heijboer MP, Bierma-Zeinstra SM, Verhaar JA, Weinans H, Waarsing JH. “Cam impingement causes osteoarthritis of the hip: a nationwide prospective cohort study (CHECK).Ann Rheum Dis. 2013 Jun;72(6):918-23.
  15. Charbonnier CKolo FCDuthon VBMagnenat-Thalmann NBecker CDHoffmeyer PMenetrey J. Assessment of congruence and impingement of the hip joint in professional ballet dancers: a motion capture study. Am J Sports Med. 2011 Mar;39(3):557-66.