Connecting To Your Feet In Yoga

Greetings Friends, 

Welcome back to The Daily Bandha. I’m just now returning to the blogosphere after completing an intensive year of study in Sports Medicine and will be sharing with you some of the knowledge I gained about the body and how to apply it to your yoga practice and teaching. Our first post in this series looks at a common disorder that can affect the foot.

You can learn a great deal about the normal function of the musculoskeletal system by looking at what happens when things go wrong. This knowledge can be used to deepen your practice, prevent injuries and to understand the role of yoga as a therapeutic adjunct in the management of various disorders. With this in mind, let’s focus on the condition known as adult acquired flat foot deformity, its anatomical basis and how to work with yoga to maintain a healthy foot arch.

As I discuss in "The Key Muscles of Yoga" and "The Key Poses of Yoga", mobility and stability about the joints is a function of three variables; the shape of the bones, the capsuloligamentous structures that connect the bones to each other at the joints, and the muscles that surround the joint. Adult acquired flat foot deformity is a disorder that relates to a muscular insufficiency of the tibialis posterior muscle, which in turn leads to weakening of the calcaneo-navicular ligament and then collapse of the bony arch.

The underlying muscular imbalance in acquired flatfoot deformity is between the weakened tibialis posterior muscle on the inside of the foot and its stronger antagonist, the peroneus brevis muscle on the outside. This imbalance places undue stress the calcaneo-navicular ligament that can lead to pain and collapse of the medial foot arch.

The exact underlying cause of adult-acquired flatfoot deformity is unknown, but is thought to be multifactorial; however, the muscular imbalance I describe is well established. In addition, it is associated with tightness of the Achilles tendon and its associated muscles, the gastrocnemius and soleus (so stretching these muscles can be an important factor in management and prevention). This problem affects women more frequently than men, typically at around the 6^th decade of life.

Here’s the anatomy:

(Note: if you’re new to anatomy, focus on studying the images.)

The calcaneo-navicular ligament runs between the calcaneus, or heel bone and the navicular bone. The navicular is a boat shaped bone in the medial mid-foot (hence its name). This ligament is an important stabilizer of the medial longitudinal foot arch.

The calcaneo-navicular ligament supports the medial arch of the foot

The key muscle providing support for the calcaneo-navicular ligament is the tibialis posterior. This muscle originates from the interosseous membrane, the upper 2/3rds of the posterior fibula and the upper posterior tibia. After passing under the calcaneo-navicular ligament, it splits into two parts: one inserts onto the navicular bone and the other divides again to insert onto the plantar surfaces of second through fourth metatarsals and the second cuneiform bones (of the midfoot).

The bones of the foot with muscle insertions

The principle action of the tibialis posterior is to invert (supinate) the foot, with secondary actions of adduction of the foot and flexion of the ankle. It is an important stabilizer of the midfoot during the “heel off” phase of walking. The tibialis anterior muscle, which inserts onto the inside of the midfoot, works with the tibialis posterior to invert (supinate) the foot.

Pressing down the outer edge of the foot engages the tibialis posterior and anterior

The antagonist to the tibialis posterior is the peroneus brevis muscle, which originates from the lower 2/3rds of the lateral (outer) fibula bone and inserts onto the styloid process at the base of the fifth metatarsal. It acts to evert (pronate) the foot and plantar flex the ankle. The peroneus longus works with the peroneus brevis to evert (pronate) the foot. It also helps to stabilize the transverse arch.

Pressing the ball of the foot engages the peroneus longus and brevis

Here’s the yoga cue…

In standing poses like Utthita Trikonasana, press the outer edge of the foot into the mat to engage the tibialis posterior. Holding this action, then press the ball of the foot into the mat to engage the peronei. Note how the medial (inside) foot arch lifts. This sequence of cues: 1) uses the tibialis posterior to support the medial arch and; 2) uses the peronei (on the outside of the lower leg) to provide resistance to strengthen its antagonist, the tibialis posterior. The biomechanical term for simultaneously engaging antagonist muscles is “co-contraction” or “co-activation”. We illustrate many examples of co-activation in the Yoga Mat Companion book series.

Co-activating the muscles that invert and evert the foot

Once you get a feel for this in the back foot, then try the same sequence in the front foot, and then in other poses such as tadasana. To see an example of this in downward facing Dog Pose click here. You can also combine it with engaging the thoracolumbar fascia to lengthen the trunk in Dog pose. Click here for more information on the thoracolumbar fascia.

Working with these types of cues strengthens the arch of the foot. This gives a feeling of lightness in the step as we go through the day. Remember that the feet are important centers in energetic anatomy and physiology and are thought to be the location of minor chakras. Finally, look at the importance of the feet for the mind-body connection, as illustrated by their representation in the brain on the homunculus.

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

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

Thanks for stopping by. Be sure to click here to page through our complete books. Stay tuned for our next post on the foot and yoga. Also, please be sure to share us on Facebook and Twitter.

All the Best,

Ray Long, MD

References:

1) Alvarez RG, Marini A, Schmitt C, Saltzman CL. “Stage I and II posterior tibial tendon dysfunction treated by a structured nonoperative management protocol: an orthosis and exercise program.” Foot Ankle Int. 2006 Jan (1): 2-8

2) Imhauser CW, Abidi NA, Frankel DZ, Gavin K, Siegler S. “Biomechanical evaluation of the efficacy of external stabilizers in the conservative treatment of acquired flatfoot deformity.” Foot Ankle Int. 2002 Aug; 23 (8): 727-37.

3) Imhauser CW, Siegler S, Abidi NA, Frankel DZ. “The effect of posterior tibialis tendon dysfunction on the plantar pressure characteristics and the kinematics of the arch and the hindfoot.” Clin Biomech. 2004 Feb;19(2):161-9.

4) Lin JL, Balbas J, Richardson EG. “Results of non-surgical treatment of stage II posterior tibial tendon dysfunction: a 7- to 10-year followup.” Foot Ankle Int. 2008 Aug;29(8):781-6