Balanced Muscular Action of the Feet and Lower Leg by Ken Blank

Whenever our feet are in contact with the ground they become part or all of our foundation. As in any structure, our personal foundation must be strong and properly formed. The muscular actions of the feet affect the alignment of the lower leg. The muscular actions of the lower legs affect the knees above and the feet below.

Muscular imbalances in the foot or lower leg can be the cause of plantar fasciitis, bunions, hammer toe, fallen arches, or knee pain. Balancing the muscular actions of the foot, leg, and thigh (see the fourth blog, “Balanced Muscular Action of the Thigh”) can prevent and in many cases reverse these problems. 

Muscles that have their insertion and origin in the foot are known as intrinsic; muscles that have their insertion in the foot and origin in the lower leg are called extrinsic. (See the third blog, “An Alignment Principle to Balance Muscular Action”, for a discussion of origin and insertion.) To balance the muscular actions of the feet, stand with your feet straight with weight evenly distributed on the four corners of your feet. The four corners are the mound at the base of the big toe, the inner heel, the mound at the base of the little toe, and the outer heel. Lift and spread your toes while keeping the four corners anchored down. This action concentrically engages the toe extensors (intrinsic muscles on the top of the feet) and eccentrically lengthens the toe flexors (intrinsic muscles on the bottom of the feet.) Toe extensors are phasic muscles and toe flexors are postural muscles. (See the second blog, “Postural and Phasic Muscles”, for a discussion of phasic and postural muscles.)

Balancing the muscular actions of the lower leg is a little more difficult because it requires the concentric engagement to go from origin to insertion (the body naturally contracts from insertion to origin) and then eccentric lengthening from insertion to origin (the body naturally lengthens from origin to insertion). Reversing these natural actions prevents hyper extension of the knee. 

To balance the muscular actions of the lower leg, concentrically engage the muscles on the lateral (outer) side (fibularis longus and fibularis brevis) from the top of the lower leg to the ankle. Then, eccentrically lengthen the muscles on the back of the lower leg (gastrocnemius, soleus, tibialis posterior, and flexor digitorum longus) from the achilles tendon to the knee. The muscles on the front and lateral side of the lower leg are phasic, and the muscles on the back of the lower leg are postural. The muscles on the front of the lower leg (tibialis anterior and extensor digitorum longus) are difficult to isolate. Concentrically engaging only the lateral lower leg muscles will suffice to balance the muscular action. 

These balancing muscular actions of the foot and leg will set the foundation to align the rest of the body and bring more strength, flexibility, and ease to your yoga practice.

Stay Tuned! Next blog: Arms and Hands