By Christy Cael
Originally published in Massage Bodywork magazine, March/April 2010. Copyright 2010. Associated Bodywork and Massage Professionals. All rights reserved.
The posterior tibialis is the deepest muscle in the posterior low leg. It is located deep to gastrocnemius and soleus, which form the bulk of the calf, and between flexor digitorum longus and flexor hallucis longus.
The muscle belly anchors to the tibia, fibula, and the interosseous membrane between the two bones. Inferiorly and medially, the tendon takes a sharp angle through the tarsal tunnel, a space between the medial malleolus and calcaneus that is similar in function to the carpal tunnel of the wrist and hand. The other muscles of the tarsal tunnel include the flexor digitorum longus and flexor hallucis longus. (Hint: to remember this group, think of Tom, tibialis posterior; Dick, flexor digitorum longus; and Harry, flexor hallucis longus. You can also replace the and with N to remind yourself that the posterior tibial nerve also runs through the tunnel.)
After passing through the tarsal tunnel, posterior tibialis follows the curve of the medial arch onto the bottom of the foot. There, it spreads like a spiderweb and inserts onto eight separate bones, including the navicular, cuneiforms, and second, third, and fourth metatarsals. This broad insertion provides dynamic support to the medial arch and controls pronation or flattening of the foot. Maintaining a neutral arch is a critical element of healthy posture for the lower extremity.
Posterior tibialis is most active during weight-bearing activities such as walking, running, and jumping. It holds up the medial arch of the foot as weight is shifted from the heel to the ball of the foot. Maintaining proper strength and endurance in this and the other arch-supporting muscles such as anterior tibialis, flexor digitorum longus, and flexor hallucis longus prevents overuse injuries such as tendonitis, periostitis, and plantar fasciitis. Such injuries are common, particularly in individuals with pes planus or an overpronated foot, which puts excessive strain on these muscles.
Palpating Tibialis Posterior
Positioning: client prone with flexed knee
1. Stand next to the client's lower leg and locate the medial edge of the tibia with your fingertips.
2. Slide your fingers posteriorly and hook around the edge of the tibia onto the fibers of posterior tibialis.
3. Continue to palpate the feathered fibers of posterior tibialis deep in the posterior leg between the tibia and fibula.
4. Client resists plantar flexion and inversion to assure proper location.
Christy Cael is a nationally certified massage therapist, certified athletic trainer, and certified strength and conditioning specialist. Her private practice focuses on injury treatment, biomechanical analysis, craniosacral therapy, and massage for clients with neurological issues. She is the author of Functional Anatomy: Kinesiology and Palpation for Manual Therapists (Lippincott Williams Wilkins, 2009). Contact her at firstname.lastname@example.org.
Editor's Note: The Client Homework element in Functional Anatomy is intended as a take-home resource for clients experiencing issues with the profiled muscle. The stretches identified in Functional Anatomy should not be performed within massage sessions or progressed by massage therapists, in order to comply with state laws and maintain scope of practice.