Relevance and Proof: Bringing Yoga Into the 21st Century through Biomechanical Standardization
by Ginger Garner MPT, ATC
Yoga’s popularity in the United States, and its potential as a method for healing, cannot be ignored. Americans are increasingly proactive, savvy 21st century health care consumers who are demanding that health care deliver “holistic” care, not just sick care for their diagnosis code. The number of Americans practicing yoga jumped by 87% to an estimated 16.5 million from 2004 to 2008, putting it in the top 10 complementary and alternative medicine (CAM) modalities used, according to a National Health Interview Survey.1,2 The National Center for Complementary and Alternative Medicine reports Americans spent $34 billion dollars on CAM therapies and just under $6 billion dollars on yoga and yoga related products alone.1,2 (Figure 1)
Yoga as medicine is also emerging and “represents the next great yoga wave.”1 Yoga therapy is possibly the first new health care field of the 21st century, and the increasing independence which Americans are seeking in out, brings three points of concern. First, only 6.5% of health care professionals recommend yoga to their patients.1
Second, yoga (and yoga therapy) are not regulated in the United States by any licensing body or agency. Third, it remains unclear how we can ensure that the consumer of yoga is safe.
The strongest argument for yoga’s evolution is safety of the American consumer, who is fraught with chronic disease, pain, and co-morbidities. The current state of Americans’ health points toward alarming decline. Despite spending more money on health care than any other country, the United States is now ranked 15th in mortality rate, falling behind countries like Finland, Portugal, Ireland, and the UK.3 Risk factors for chronic disease, like obesity, has increased 132% since 1990, rising to an almost 30% epidemic rate in the U.S.3 Yoga must evolve to meet the needs of the average American suffering from a wide range of diseases and illnesses that are by-products of our modern lifestyle, pollution, and environmental changes not experienced by ancient yoga culture.
Additionally, lack of regulation of yoga in America allows anyone to teach yoga. Standards set by the U.S.-based Yoga Alliance (YA) are per their mission, “voluntary and minimum,” offering no measure of proficiency, accreditation of schools, certification of teachers to train in yoga, standardized testing of competencies, or objective supervision or oversight of teachers or schools. Without educational standards, a scope of practice, and jurisprudence for yoga as a new health care profession, it is difficult to establish a dialogue between east/west medicine, encourage medical professionals to recommend or use yoga with their patients, or ensure safety of the yoga consumer.
Despite these obstacles I am confident, having taught for more than 15 years, that yoga can evolve and grow to meet the complex needs of and safeguard the 21st century citizen. To achieve the mission of the International Association of Yoga Therapists, which is “for yoga to be a recognized and respected therapy,” the following actions should be considered.4
1. Yoga should be viewed as an art and science that affects health and therefore should be subject to creation of the same legal, clinical, and educational standards, accreditation and licensing process as other health care professions.
2. Yoga practiced must be evidence based and include experiential training and onsite direct clinical application and experience. “With so many Americans using and spending money on CAM therapies, it is extremely important to know whether the products and practices they use are safe and effective. It is important to conduct rigorous research and provide evidence-based information on CAM so that health care providers and the public can make well-informed decisions,” according to Josephine P. Briggs, MD, director of National Center for Complementary and Alternative Medicine.2
3. A healthy dialogue between Eastern and Western medical communities must exist. Yoga must incorporate evidence based Western medicine into its practice and Western medicine should embrace yoga’s holistic model for healing.5
4. Mind/body yoga curricula should be included in future medical and allied health programs, either as electives or through the addition of a certificate subspecialty or license in post-graduate practice of medical therapeutic yoga.
5. Standardization of biomechanical alignment of yoga postures (asanas) and breath (pranayama) based on current science in joint and organ structure and function should be implemented.
The case for biomechanical standardization
Currently there is no agreement on how yoga postures or breath should be biomechanically aligned or executed. Yoga postures have historically been taught based on verbal knowledge handed down from guru to student, rather than on scientific evidence and rationale. However, standardization can be accomplished based on the therapeutic intention of the pose and critical application of fundamental knowledge in scientific arenas such as joint structure and function, anatomy and physiology, physics, emerging neuromuscular science on neural and myofascial tension, emotional motor control, and medicine.
I have been teaching a standardized method, documented photographically and in print, to medical professionals for 10 years. The method gives emphasis to the most commonly seen pathophysiologies in therapy such as cervicothoracic, lumbopelvic, scapulohumeral, and lower quarter alignment, and cardiopulmonary dysfunction, pain, and its emotional factors.
Implementing a biomechanical standardization for evaluation and alignment of postures, like the case of downward facing dog which follows, would improve yoga education, promote safety and efficacy in posture instruction and performance, and ultimately improve health care delivery in prevention, wellness, or rehabilitative settings.
Downward facing dog (DFD): A postural case example
Downward facing dog (adho mukha svanasana [ahd-dough moo-kuh shvah-nah-suhn]) is perhaps the most recognizable and as a result, most practiced yoga posture in the U.S. today. The pose is revered as a foundational in the classical yoga posture system, and is taught in novice to advanced classes alike.
However, DFD comprises numerous biomechanical degrees of freedom in multiple joints that require remarkable neuromuscular control and musculoskeletal proprioceptive awareness. The complexity of DFD renders it a high risk posture, and in many cases is contraindicated for a large portion of the American population, especially the more than 80% that will suffer from low back pain.6 Traditional teaching of the pose does not typically consider research in the physiology, biomechanical alignment, or arthrokinematics required for normal osteokinematic range of motion. In addition, regional interdependence (the concept that “unrelated impairments in a remote anatomical region may contribute to, or be associated with, the patient’s primary complaint”) should be considered.7,8 Evidence supports that clinically significant outcomes are achieved when the regional interdependence concept is utilized to guide providers in decision making.9-15
Precepts for biomechanical alignment of postures
Four evidence-based precepts serve as guidelines for biomechanical alignment. After these are understood, a series of postures called “pre-postures or pre-asana,” are introduced to serve as a gateway for safe performance of all postures.
1. All postures, unless restorative, are taught using transversus abdominis (TvA) assisted thoraco-diaphragmatic breath, or TATD breath, and the trunk cylinder concept.
TATD breath is imperative for use during yoga postures because of its provision of lumbopelvic and concomitant synergistic regional stability. The TATD theory is based on research in lumbopelvic stabilization and diaphragmatic physiology showing TvA activation precedes limb movement, is continuous during all trunk movements, is controlled independently of other trunk muscles, is required for trunk stability, and lends stiffness to the trunk via increased IAP (intra-abdominal pressure).16-18 The practice of co-contraction of the trunk cylinder (see figure 2) for stability and injury prevention in the lower quarter is also well supported as one of the requisites for lumbar and pelvic stabilization, which has carryover for the lower extremities based on the regional interdependence model (Table 1).19-23 Co-contractions of as little as 1% to 2% of the MVC (maximum voluntary contraction) for a healthy spine, 2-5% for a compromised spine, and as much as 25% of MVC are sufficient for joint stabilization, important in establishing trunk stability during postures.25-27
Additionally, the trunk cylinder concept, the model for core stability, is used to provide synergistic support for safety in postures.19, 53 (Figure 2) The respiratory and pelvic diaphragms are local stabilizers of the trunk; therefore, they contribute to trunk stiffness and stability.20,29,30,53-56 Trunk cylinder physiology in the TATD breath facilitates trunk stability through increased intra-abdominal pressure via concomitant concentric “drawing in” action of the TvA and descent of the respiratory diaphragm.20,29,30,50,52,53 This “antagonistic synergistic action is required for efficient use of the diaphragm” and increases the transverse diameter expansion of the rib cage via fixation of the respiratory diaphragm’s central tendon, rather than the sole expansion of the abdominal region which occurs in a diaphragmatic breath without abdominal involvement.20,29,30,52,53
2. Stabilization is prioritized over mobilization with emphasis given to lumbopelvic stabilization principles via externally or internally supported yoga postures.
Stability, as the primary focus, is not about the “amplitude of the motion but rather about how well an individual can control the amount of movement they have.”24 Lumbopelvic stability requires four components to occur in the Integrated Model of Function: form closure, force closure, neural patterning and motor control, and emotional factors contributing to physical health and performance.28,34,35,37
Form and force closure are dynamic, achieved by teaching internally supported (through neuromuscular education, musculoskeletal strengthening, and endurance training) poses. In the absence of internal support, passive rehabilitation methods via externally supported (props, blocks, blankets, bolsters, plinths, chairs, etc) poses are substituted.
Lastly, functional knowledge of open and closed packed joint positions combined with breath sequencing and maintenance of plumb line alignment during spinal neutral postures are used to position and progress postures.33,36 (Figure 3) Open packed and closed packed joint positions describe the position of a joint where there is the most and least arthrokinematic range of motion available, respectively.
3. Protection of small joints (hands and feet) should be emphasized to prevent injury during postural performance.
The protection of the lower quarter particularly requires heeding requisites for joint stability (i.e. co-contraction of lower extremity musculature; also see table 1), which also include proper biomechanical alignment of weight bearing postures to honor plumb line alignment in all planes of motion in addition to dynamic rules governing gait (for transfers in, out of, and between yoga postures). The downward dog posture follows as a functional application of this rule.
4. When flexibility of connective tissue is a goal, avoid eliciting the myotatic stretch reflex by employing thirty second holds in all postures.38,39 This practice utilizes the concepts of viscoelasticity, load deformation (see stress/strain curve in Figure 4), and creep, and also gives respect to neural tension, neural mobilization, and the possibility of myofascial restriction.40
Creep is a constant force (compressive or tensile) which over time causes a material to continue to deform (or lengthen) until its limit (state of equilibrium) has been reached. “The properties of creep provide much of the rationale for myofascial release and aspects of neuromuscular therapy and need to be taken into account during technique applications.”41 Fascia plays an important role as a muscle force generator via tension transmission between the epimysium, movement regulator via contraction in a smooth muscle-like manner, and as a movement inhibitor.42,43,44,46,47 Musculoskeletal dynamics of yoga postures, then, are intimately affected by the health of the fascia. Downward facing dog, as a result, can be used in both diagnostic and evaluative roles.
Upper quarter alignment pre-posture (asana): Arm spiral
In preparation for downward facing dog, trunk stability and alignment depend on the requisites of TATD breath and arm spiral mastery being concomitantly performed with TvA initiation. TvA contraction should be maintained in TATD breath throughout respiration while performing DFDP (see figure 6 for illustration and explanation).
The arm spiral is a foundational pre-posture used in postures involving upper extremities. The clinician must evaluate the arm spiral in open and closed kinetic chains for scapular deformities such as lack of inferior medial rotation resulting in scapular tipping and winging (see figures 5-13).
To assess, perform glenohumeral abduction to 90°, glenohumeral external rotation, scapular depression, medial rotation, and retraction, and concomitant forearm pronation. The fingers remain abducted to develop intrinsic hand strength and proprioceptive awareness. The end result is a co-contracted concentric tricep and wrist flexor moment and an eccentric bicep and wrist extension moment. Look for compensatory actions in secondary muscles of respiration and upper extremities, such as shoulder shrugging and loss of glenohumeral external rotation. (Figure 5) Modifications can be made by lowering the arms to 45° or performing in supine hook lying.
Trunk lower quarter alignment pre-posture: Downward facing dog preparation (DFDP)
DFD and DFDP should be executed to respect the spinal curves via maintenance of trunk plumb line alignment or spinal neutral (Figures 6, 8-13). Notice incorrect alignment in figure 14 secondary to reversal of the lumbar lordosis and thoracic kyphosis. Lastly, look for lateral shifts, vertebral rotations, sacroiliac malalignment, or evidence of scoliosis and take clinical measures to cue for correction or treat the anomaly.
Lower quarter alignment should identify and correct any genu varum or genu valgum to avoid increased supination or pronation moments, respectively.30 Because the ankle is capable of greater than 15° of transverse movement, identify and give cues for correction of forefoot instability (i.e. verbal cuing for self-correction and proprioceptive awareness, tactile cuing to provide external support via blocks, wall, or blankets, and visual cuing can be used) via employment of joint stability prerequisites (see table 1) and evaluation of proximal and distal joints for pathology within the pose.32
Lower extremity pathologies that could require verbal, manual/tactile, or visual cueing (which could include providing external support to modify the pose) include hallux valgus, excessive pronation, supination, chronic ankle instability, Achilles tendinitis, or other instability, proprioceptive dysfunction or functional limitation in dorsiflexion and eversion. The biomechanics of DFD require full ankle dorsiflexion, which can be a limiting factor; however, in more than 16 years of teaching and practice, I have been able to successfully modify DFD for all my lower extremity patients using props or changes of position. For example, DFD can be performed with the heels on blankets or supported by a wall; alternately, DFD can be performed from a chair or with wall support, which does not require normal foot range of motion.
In the absence of props or modifications, a foot deformity such as forefoot varus can prevent normal termination of subtalar joint pronation during a full weight bearing DFD.49 This position creates instability, which causes excessive extrinsic foot muscle activity and increased ligamentous stress through the joints of the foot, which in turn could eventually lead to repetitive stress disorders such as subluxation.49 Lastly, maintain co-contraction of anti-gravity musculature and perform the final DFD in two variations, straight and slightly flexed knees, to address flexibility of both the gastrocnemius and soleus.
The DFDP combines TATD breath, arm spiral and hands and knees four point posture to generate trunk stability and synergistic action via regional interdependence of the hip and trunk and the trunk cylinder concept.51 Neuromuscular re-education for developing healthy breathing habits, and lumbopelvic, scapulohumeral, general posture, or lower quarter alignment and stability can be employed at any stage of training for DFDP through giving feedback visually, manually, or verbally. The use of mirrors in the practice area or studio is invaluable for biofeedback training and self-correction. Ultimately, the goal is to allow the patient to self correct in a posture without the aide of external feedback or props, when appropriate.
Action: Four point position
Entry – Align the hands under the shoulders with the arms in arm spiral at shoulder width. The knees should be hip width. Engage the navel into the spine (TvA initiation) without loss of trunk plumb line alignment or TATD breath.
Exit – This is a transition posture into DFD.
Action: Downward facing dog preparation
Entry – On an exhale, engage the TvA and begin TATD breath. On the next exhale, lift the knees 1 to 2 inches off the floor and hold for five breaths.
Exit – Lower to mat after five breaths. Repeat 10 times or as necessary for neuromuscular re-education.
Modifications – Use external supports such as blocks, a wall, or chair; or, perform from the forearms for DFDP and DFD. Circumstances that would require modification include osteoarthritis (OA), rheumatoid arthritis (RA), or an active or chronic lesion or injury involving weight bearing joints. For example, I often use blocks under the hands, a strap that binds the arms just below the elbows at shoulder width (to facilitate proximal stabilization), and limit weight bearing through the wrists and hands when patients have pre-existing OA or RA. Depending on the severity, I may put them in the water, on a theraball or Swiss ball with hands on the wall, or mimic DFDP and DFD using chairs or walls to prevent load bearing through the upper or lower extremities.
Action: Downward facing dog
Entry – From DFDP move slowly and carefully into DFD, maintaining spinal alignment and TATD breath.
Exit – Inhale and return to four point position.
Yoga can be a very useable healing art and therapeutic science for improving quality of life, health care, and its delivery if consumer safety is kept paramount. Unifying eastern and western medicine and addressing the need for regulation and standardization of physiological practice of yoga postures can help diminish dogma and banish any lingering stigma surrounding yoga.
Health care providers should be encouraged to get involved in the process of safeguarding yoga for patients and consumers as well as learn more about using and recommending yoga to their patients. A future of mutually beneficial dialogue which bridges the gap between east and west medicine is in our grasp. Our actions today to embrace yoga can facilitate its future evolution and enact massive positive change, making yoga accessible and safe for all Americans.
Ginger Garner MPT, ATC is a long time orthopaedic and women’s health physical therapist based in Emerald Isle, NC, specializing in yoga as medicine.
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Source: Nahin, RL, Barnes PM, Stussman BJ, and Bloom B. Costs of Complementary and Alternative Medicine (CAM) and Frequency of Visits to CAM Practitioners: United States, 2007. National health statistics reports; no 18. Hyattsville, MD: National Center for Health Statistics. 2009. Credit: Reprinted with permission from National Center for Complementary and Alternative Medicine, NIH, DHHS.
Figure 2-14, Table 1. Source: Garner, Ginger. Professional Yoga Therapy: Mission for Today, Model for the Future. Manual One. 5th edition. Browndog Media Group, NC. ©2010.
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