PT Classroom - Physical Therapy Implications in Treating Tibialis Posterior Tendon Dysfunction ׀ by Sarah Meuler, DPT

In the outpatient setting, treating clients with ankle and foot pain is common practice. By making observations on the structure of the foot as well as analyzing gait, physical therapists are able to determine the cause of the pain. In many cases, the tibialis posterior tendon contributes to pain and dysfunction among clients with pes planus. Pes planus, hindfoot valgus, flatfoot deformity, and fallen arch are many of the names given to describe an insufficient tibialis posterior tendon. Given the commonality of tibialis posterior tendon dysfunction (TPTD) in the outpatient setting, there is very little information published on evidence based practice of treatment for TPTD. In researching this topic, I found a dynamic approach to be the most effective in conservative treatment and long term management of TPTD.

Anatomy Review
The tibialis posterior is a muscle deep in the posterior compartment of the lower leg. The tibialis posterior, along with the flexor hallucis longus and the flexor digitorum longus muscles, lie beneath the soleus and originate from the posterior side of the tibia, fibula, and interosseous membrane. The tibialis posterior, flexor digitorum longus and flexor hallucis longus tendons, are comically known as the “Tom, Dick and Harry” tendons based on their anatomical presentation from anterior to posterior as they cross the ankle behind the medial malleolus. These three muscles act to supinate or invert the foot and in a lesser sense also are activated in plantar flexion. On the plantar aspect of the foot, the tibialis posterior tendon divides into multiple superficial and deep portions to form attachments to every tarsal bone with the exception of the talus. The deeper divisions find attachments at the bases of several of the more central metatarsals. The widespread insertions of the tibialis posterior form and support the medial longitudinal arch. (1)

Kinematics
Although the tibialis posterior, flexor hallucis longus, and flexor digitorum longus assist the gastrocenemius and soleus in decelerating dorsi flexion and accelerating plantar flexion in late stance, their main action is to control pronation and supination movements during ambulation. In early stance, the tibialis posterior decelerates pronation of the rearfoot. While decelerating pronation the tibialis posterior assists in lowering the medial longitudinal arch, eccentrically helping to absorb some of the impact from loading (1). Concentrically, the three muscles help to supinate the rearfoot in mid to late stance to prepare for toe-off.

Clinical Presentation and Assessment
Due to the important actions of the tibialis posterior in the stance phase, it is easy to overload the tendon causing overuse dysfunction. In a study by Neville et al. it was found that the tibialis posterior tendon lengthens much more in an individual with known dysfunction as opposed to a healthy walking individual (2). Clinically, I have found that clients with TPTD will present with medial longitudinal arch pain and display a positive navicular drop test. Many also have tenderness to palpation of the tendon insertion on the navicular tuberosity. During gait, these clients tend to excessively pronate and lose the structure of the medial arch. Clients with TPTD may also have difficulty performing a heel raise or walking on their toes secondary to medial arch pain. In a different article by Neville, Meyers, and Hojnowski, a high-frequency ultrasound was used to assess the integrity of the tibialis posterior tendon in a person with medial arch pain. The ultrasound assessment was significant for tendon enlargement, disruption in tendon structure, and fluid surrounding the tendon (3). Even though we tend to think of TPTD as a chronic, overuse injury, there is evidence that an inflammatory component may also be present.

Treatment
Conservative therapy should always be trialed prior to surgical intervention to treat a severe flatfoot deformity. Although orthotics are typically indicated in treatment of tibialis posterior tendon dysfunction, strengthening and stretching have also been effective in increasing overall function. In a randomized controlled trial by Kulig et al. it was determined that people with early stages of tibialis posterior tendinopathy initially benefited from orthotics wear and stretching. Eccentric and concentric progressive resistive exercises further helped to reduce pain and improve perceptions of function (4). Since the tibialis posterior plays key roles in deceleration of pronation and acceleration of supination, studies have shown both eccentric and concentric strengthening to be beneficial in treatment of TPTD (5). Intrinsic strengthening of the foot may also be indicated as the intrinsic muscles assist the tibialis posterior in supporting the arch during gait.

Although there is a lack of research in evidence based, non-surgical treatment of tibialis posterior dysfunctions, it is important to focus on biomechanical analysis of the gait cycle to determine the root of the cause. Footwear and orthotic assessment are essential for long-term management of tibialis posterior dysfunction to decrease pain and restore normal kinematics. Manual therapy and joint mobilizations should also not be overlooked to decrease pain and restore function. Most importantly, conservative treatment of tibialis posterior dysfunction should be client specific to ensure proper follow through with the physical therapy plan of care.