Back bends are my favourite postures to teach as here I witness the biggest transformations!
The main concern sighted by the general yoga community for not using glute max in back bends is that excessive external rotation of the thighs can jam the sacrum between the two halves of the pelvis. An inability of the sacrum to float freely between the pelvic halves at the sacroiliac joints is a common source of sacral, hip and low back pain. However, it is not only activation of glute max that is the cause of this adverse effect but equally over activation of all the deeper lateral rotator muscles of the hip, including the piriformis muscle. The lower fibres of glute max do attach to the outer rim of the sacrum but the piriformis has an even greater lever on the sacrum. It originates on the front (anterior) aspect of the sacrum (S1 – S4) and extends horizontally across the buttocks to insert on the greater trochanter of the thighbone (the most lateral boney protrusion on the outside of your hip). The main action of the piriformis is external rotation of the thigh but it is its tendency toward facilitation (one or both sides) that makes it prone to spasm, which is a major cause of sacral jamming.
One could attempt to counter-act the feet turning out by engaging the internal hip rotator muscles (gluteus medius, gluteus minimus, tensor fascia latae, the anterior portion of adductor magnus, gracilis and pectinius) by grounding the medial side of the feet in back bends. However, turning the feet out in backbends is more accurately a sign or symptom of counter-nutation of the sacrum! Counter-nutation of the sacrum usually partners with the action of posteriorly tilting the pelvis, compressing the spine and ribcage forward and down and externally rotating the limbs. The opposite happens with nutation of the sacrum: the spine lengthens into extension, the ribcage lifts and opens and the limbs rotate inwardly. Posteriorly tilting the pelvis is initiated by glute max. Herein lies the potential problem – this as the start position for back bending. Sequencing and queuing is of utmost importance, which brings us back to my initial stance that the position of the sacrum in nutation with the pelvis anteriorly tilted is imperative to graceful back bending. With this method, keeping the feet straight in backbends is effortless and prevents excessive engagement of the deep lateral rotator muscles. This keeps the feet aesthetically positioned and prevents sacral jamming.
Some students choose not to use their glute max in back bends as this brings them relief of low back pain. Using glute max is not the problem. The problem is when they are engaging glute max. If you start your backbend by first firing glute max you will most likely posteriorly tilt the pelvis and have your sacrum in a counter-nutated position. With the sacrum counter-nutated the fulcrum of the backbend will be forced into the lowest vertebral joints (L4/L5/S1) only. As you can imagine this will eventually cause low back or sacroiliac pain. The reason relaxing glute max relieves this type of low back pain is because glute max was being used to posteriorly tilt the pelvis. Trying to do a backbend with the pelvis tilted backward and the sacrum counter-nutated points to a greater likelihood or developing low back pain.
As well as sequencing instructions in the order of first tipping the pelvis forward and creating a curve in the low back (which means the sacrum will be in a nutated position) and then engaging our major hip extensor muscle (glute max), a teacher’s choice of terminology can help students to refine their performance of back bending postures. For example, instructing students to ‘squeeze’ or ‘clench’ their buttocks can induce premature and indiscriminate activation of glute max along with the deep external rotators. If you aggressively engage glute max you may undo the anterior pelvic tilt of the pelvis and as the pelvis tilts posteriorly the sacrum will travel with it into counter-nutation. As nutation inspires the spine to unravel and lengthen into extension, counter-nutation causes the contrary and encourages the feet to turn out.
Of course not all back bends are the same and in those where gravity does a lot of the extension for you (eg, Ustrasana and dropping back from standing), engaging glute max may be less important. However, you still do want to target your movement of extension over the hip joint so that the axis of backward rotation is not focused into the lumbar spine but is focused more across the hip joint. Gray Cook the founder of ‘Functional Movement Systems’ describes the tendencies of different joints toward mobility or stability. The hip joint is inherently stable and thereby tends toward stiffness. At the other end of the spectrum, the lumbar spine is inherently mobile and tends toward instability. The action of glute max helps to combat this stiffness by specifically inhibiting the hip flexor muscles, which prevent us from arching backward, whilst relieving the low back vertebrae of excessive movement and instead, providing them with much needed stability.
There is one point in a back bend where we could choose to disengage our glute max and that is once full extension of the pelvis has been reached. Here is it is possible for many students to relax their glute max and still maintain their back arch. This will depend to some degree on your flexibility, muscle mass and the inherent resistance of your muscle tone. If you are very flexible in a back bend you may not need to engage glute max to achieve a deep back bend but you do need to note where the fulcrum of the movement is: in your low back or at your pelvis.
To not use glute max in back bending postures perpetuates the tendency for inhibited glutes and shortened hip flexors. Additionally, glute max provides us with 70% of our pelvic stability. Gait is our most frequent functional movement pattern. Without glute max to initiate the propulsion and produce extension of the hip joint this movement loses its integrity. In our analytical attempts toward precision and correct alignment in complex postures we risk losing the natural integrated movement pattern require to perform the posture. Every posture is a set of unfolding functional relationships. The natural ‘gait’ of back bending requires glute max to stabilise the pelvis, to provide a safe, secure pivot point for extension, to protect the low back and to enable us to safely enjoy the tremendous benefits of arching backward.
[PICTURE: Green arrows depict the coupled motions of sacral nutation, anterior tilt of the pelvis and lengthening of the lumbar spine into extension. The blue arrow demonstrates the extension of the hip joint performed by glute max.]
Always with you on the mat….
Cook Gray, Burton Lee, Kiesel Kyle, Rose Greg & Bryant Milo F. Movement: Functional Movement – Expanding on the Joint-by-Joint Approach. Available from: http://graycookmovement.com [8 July, 2013]
Janda V. Evaluation of muscle imbalances. In: Liebenson Craig, Rehabilitation of the Spine: a Practitioner’s Manual. Williams and Wilkins. Baltimore, 1995.
Liebenson, Craig. Rehabilitation of the Spine: a Practitioner’s Manual. Lippincott, Williams and Wilkins. Baltimore, 1995.
Marieb Elaine N. Human Anatomy & Physiology. Pearson Benjamin Cummings. San Francisco, 2004.