Tibialis Posterior Dysfunction
Tibialis Posterior Dysfunction (TPD) represents one of the biggest biomechanical challenges in lower limb foot and ankle pathology.
What is TPD?
Tibialis Posterior Dysfunction is a common condition causing ankle pain and heel pain, and occurs when the posterior tibial tendon becomes inflamed or torn. Stability and support may be reduced causing the pain and also potentially resulting in fall arches or flat feet.
Treatment of Tibilias Posterior Dysfunction
Early intervention with a cost effective orthoses easily fitted to a suitable shoe for the condition is essential. Waiting for the arrival of a custom foot orthoses is not an option the modern clinician should consider, especially as no significant difference has yet been found in the ability of custom foot orthoses to alter the action of tibialis posterior activity (Murley, Landorf, & Menz, 2010). Treatment needs to start the day of diagnosis. The X-Line TPD should be your first line of defence against this potentially crippling injury.
TPD is most easily diagnosed by the following simple techniques, starting with some simple questions. First the patient usually complains of pain on the medial ankle and may or may not experience symptoms radiating up the distal medial shin. The patient may have noticed a change in their foot profile.
This should consist of careful palpation from the navicular tuberosity proximally along the route of the tibialis posterior tendon to the area retro-inferior to the medial malleolus. Once reached, follow the tibia to the retro-medial-malleolar area and advance carefully up the medial edge of the tibia. Note all areas of tenderness to establish the extent of the damage and that it relates to tibialis posterior.
Now rule out a passive structural injury such as a deltoid ligament strain or tarsal tunnel syndrome by following the simple rules taught be the Cyriax approach. Perform a few simple muscle test.
Muscle tests should first be performed non-weight bearing. Have your patient sitting or lie supine. Plantarflex the patients foot and ask the patient to keep the foot plantarflexed. This reduces the ability of the patient to activate their tibialis anterior. Now ask the patient to invert the foot against at first fairly gentle resistance. Repeat this test with the foot starting from a relaxed position, the semi-everted position and finally a fully everted position, making sure the patient keeps the foot and ankle plantarflexed.
Pain against resistance in these positions indicates TPD is likely. The less everted the foot is when pain is produced the more extensive the damage is likely to be. If these tests are negative, place the foot slightly everted while again the foot is plantarflexed and this time push firmly of the foot into eversion while the patient tries to resist you. If pain is elicited then the diagnosis remains the same but the severity is likely to be less.
The final tests involve the patient standing. Getting a rear-view of the patient’ foot and clerk the patient using a foot posture technique (we recommend the Healthystep Step assessment form). Look for asymmetry between the symptomatic and asymtomatic sides. Bilateral symptoms in this condition are rare. The symptomatic side is likely to demonstrate greater pronation markers than the asymtomatic side.
Now ask the patient to rise onto their toes making sure they are semi-supported with something like the back of a chair. Watch carefully the amount of inversion of the heel as they rise up. In full heel lift both heels should appear varus, and there should be no difference in the amount of varus left to right. Failure to invert the symptomatic side, reduction in the inversion, or late occurrence of the inversion, all indicates tibialis posterior dysfunction, with the latter motion suggesting a milder form.
Classification of TPD
Tibial Posterior Dysfunction has been classified into 4 stages (Myerson, 1996):
Pain and oedema along the course of the tibialis posterior tendon-early tendinosis/ tenosynovitis.
Mild inflammatory changes noted woth no or little apparent structural deformity or tendon weakness-patient able to perform heel raise with little or no pain
Radiographs appear normal. MR and ultrasound show evidence of tenosynovitis.
Pain, oedema and tenderness along the course of tibialis posterior tendon. Mild heel vaglus, forefoot abduction, and longitudinal arch lowered on weght bearing occurs.
Flatfoot noticeable on radiographs.
MRI and ultrasound imaging show evidence of tenosynovitis, and tendinosis.
As 2A with pain also lateral ankle due to increasing planus deformation of the arch.
Increasing heel valgus, decreasing arch height and forefoot supinatus may be noted.
MRI or ultrasound may show partial rupture.
Deformity becomes more severe and fixed.
Inability to perform heel raise test, increased lateral symptoms, and adaptive forefoot varus.
Radiographic progression of pes planus foot and degeneration of joints maybe noted.
Involvement of the ankle joint and damage to the soft tissues of the ankle. Radiographs in Anterior-Posterior view may show valgus tilt of ankle and degeneration.
X-Line TPD Foot Orthoses
All Healthystep foot orthoses are designed with “phasic” control of the foot. Phasic control means the best support of the foot possible at the right moment to match the points of potential dysfunction during gait. The X-Line TPD has been developed by the Healthystep design team to meet the biomechanical stresses initiated by failure of tibialis posterior to function in all three stages of the stance phase of gait.
- The deep heel seat holds the heel comfortably and firmly, while the sagittally pitch heel skive (developed by Stephen Bloor and Andy Horwood in the 1990’s for use in custom foot orthoses made by a leading manufacturer of custom foot orthoses in the 1990’s) decelerates the eversion excursion normally reduced by the action tibialis posterior during loading response.
- The saggital arch cradle design unique to the x-line family of devices, now stabilises navicular drop as we move into midstance, enabling us to continue to protect those patients with extended tibialis posterior function, while also holding the navicular high to decrease the amount of effort required by the tibialis to raise the arch during terminal stance.
- The distal shell extension contour developed by Healthystep, stabilises the medial and lateral columns as well as the central rays to create a base for the peak activity of the tibialis posterior at heel lift. The midfoot saddle should have kept the arch higher to help reduce the peak activity that occurs at heel lift.
- Finally this remarkably well-designed device is plastic wrapped to maintain the integrity of the device, which means although the device is a total contact inlay, the plastic reinforcement means the device is less reliant on the torsion stability of the shoe, although we still strongly address this issue if your patient is wearing shoes without torsion stability.
There is no way getting around the fact that TPD needs the right kind of shoe to get better. We advise the following:
- Get your patient in lace up shoes.
- Make sure the sole of the shoe is wider than the foot.
- Make sure the shoe has torsion stability (you can’t easily twist or deform the middle of the shoe).
- Make sure the shoe has a small heel lift.
- Antipronation (motion control trainers) are often the perfect choice, especially for stage 2b or worse stages.
- Remember shoe choice seriously affects the effectiveness of an orthosis.
View our Orthotics for Tibialis Posterior Dysfunction
Each of our orthoses has been developed with specific medical conditions in mind. We offer primary products per condition, though several others have been found to help patients given the biomechanical engineering behind them.