Reducing Spring Overuse Injuries: A Closer Look at Posterior Tibilias

     Warmer spring temperatures and upcoming races mean longer runs and an increased risk of overuse injuries. Spring is common time for overuse injuries to the tibialis posterior muscle as it’s function in vital to efficient running. The tibialis posterior is a small, thin, unassuming muscle which plays a vital role in walking and running locomotion. Located on the posterior aspect of the lower leg, the tibialis posterior is deep to the easily recognizable calf musculature (gastroc-soleus muscle complex). The tibialis posterior originates on the posterior side of the fibula and tibia, and inserts on the navicular, second cuneiform, and 2nd , 3rd , and 4th metatarsal bones of the foot. Tibialis posterior weakness or injury can sideline even the most seasoned runner. Evaluation of strength and functional activity is vital to properly detecting tibialis posterior dysfunction.
     The function of the tibialis posterior is much more important than its diminutive presence in the lower leg. It acts to invert (turn inward) the foot and ankle, supinate the foot (raises the arch) and aids in dorsiflexion (upward motion of the foot) of the foot and ankle. Without the tibialis posterior, the stability of the foot and ankle is compromised significantly during walking and running. Consider for a moment a flat foot. The term flat foot has a negative connotation, but pronation (or lowering of the arch of the foot) is necessary to absorb
shock and accommodate to uneven surfaces. Supination, however, is necessary to bring a pronated, flat foot into a position of stability for push-off while walking or running. Efficient, pain-free running is dependent on the ability of the tibialis posterior to bring the foot and ankle into a supported position (through supination). Without the action of the tibialis posterior, the foot and lower leg are subjected to increased tensile strain during the stance and push-off phases of gait. Injuries such as plantar fasciitis, medial tibial stress syndrome (shin splints), knee pain, hip pain, iliotibial band pain, and even low back pain can often be traced in whole or part to a deficient or weak tibialis posterior muscle.
     Prevention and treatment of tibialis posterior dysfunction begins with body awareness and smart training habits. Tibialis posterior specific strengthening exercises include heel raises with slow lowering to the ground. Adding mild inversion as you lower your heel to the ground will bias the tibialis posterior. Band resisted ankle inversion with the ankle in plantarflexion will strengthen the tibialis posterior in non-weight bearing. Gradually increasing your mileage and easing into rough trail terrain will reduce overuse injuries in the tibialis posterior as well. If your calves or feet are tired or painful after running or weight bearing exercise, allow your body to rest, and recover for 1-3 days. If you continue to experience pain after 3 days a physical therapy evaluation may be indicated. Your physical therapist will rule out injuries such as a stress fracture, sprain, strain, compartment syndrome, or circulatory issues for which you will be referred to your physician for diagnostic testing. If the physical therapy evaluation is negative for serious injury, a Sapphire PT physical therapist will test for underlying weakness and-or inflammation responsible for your symptoms. Understanding the mechanics of walking and running and the contribution of other factors such as hip and core strength and running technique will narrow the treatment plan to a concise set of rehabilitative and preventative exercises. Your physical therapist will also guide you in a progressive return-to- activity plan based upon your response to PT treatment. The take home message is to take action when foot or medial ankle pain limits your ability exercise.
John Fiore
Sapphire Physical Therapy
john@sapphirept.com