February 1st, 2012
Posterior Tibial Tendon Dysfunction / Adult Acquired Flat Foot
I think we have all, at one point or another, heard someone mention that they have 'fallen arches'.
In the spectrum of foot health, there is a very distinct difference between what most of us consider 'fallen arches' and what can become the serious medical condition that is Posterior Tibial Tendon Dysfunction (PTTD).
PTTD usually begins from a weakness in the tibialis posterior muscle in the lower leg. The posterior tibial tendon follows a path behind the inside ankle bone and the main portion attaches to the navicular and bottom of the first cuneiform. (This would be roughly at the highest point of your instep.)
The tendon also attaches to the 2nd, 3rd and 4th metatarsals and parts of the heel.
The primary function of of tibialis posterior is to plantarflex (pull the the foot down) and invert the foot (pull the sole of the foot inward). This action has the effect of stabilizing the foot and supporting the arch. When there is weakness in the muscle or damage to the tendon, this function is compromised and the result is an unstable foot and an arch that flattens too much or for too long during walking.
4 Stages in the progression of PTTD:
Stage 1: Typically there are no painful symptoms, but your doctor may have diagnosed a bio-mechanical problem that may lead to symptoms developing if left untreated. This is the time when your doctor may suggest changing your footwear to a more supportive design and prescribe a good quality over-the-counter foot orthotic (the Birkenstock BirkoBalance or a Heat Molded UCB are good examples) or a prescription custom foot orthotic and a brief course of physical therapy to restore appropriate muscle strength and balance to prevent progression of the dysfunction.
Stage 2: Symptoms become evident and the main problem is with tendinitis, tenosynovitis or tendinopathy of tibialis posterior. There may be mild weakness developing. Your doctor may suggest moving to an athletic shoe with a strong medial counter and prescribe a customized over-the-counter orthotic like a heat mold UCBL or a custom foot orthotic to control the motion in your foot and reduce the stresses on tibialis posterior. A longer round of Physical Therapy may also be prescribed to try and address the muscle weakness and arrest the deterioration of the tendon.
Stage 3: By this time there is significant dysfunction with there is usually tendinopathy or tendinosis of tibialis posterior and the possibility of developing a tear or partial rupture of the tendon is greatly increased. There will be a marked weakness which inhibits tibialis posterior from doing it's job. The foot may be beginning to look like it is turning to the outside, a reverse 'c', as the middle of the foot flattens, becomes more rigid (lost range of motion) and the metatarsals shift laterally. Your doctor may prescribe a custom molded UCBL, custom deep heel seat foot orthotic or a custom brace to try and limit the abnormal motion in the foot and pair it with an athletic shoe or other shoe with a rigid medial counter. Physical Therapy may be a part of the treatment regimen but is unlikely to make an impact on the condition.
---The first 3 stages are treatable in degrees by orthotic and footwear intervention. The further into the progression the foot becomes, the less likely to reach a symptom free state. It is critical to catch and treat PTTD as early as possible with footwear, orthotic and physical therapy.
Stage 4: This is the end stage of the progression and there is a rapid decrease in function and increase in symptoms such as swelling and pain along the tendon course. Motion in the foot is also severely compromised due to joint rigidity and probable arthritis. At this stage your doctor is most likely to prescribe an ankle gauntlet style AFO such as an Arizona AFO or possibly suggest surgical intervention. Due to the rigidity of the foot and compromised position of the foot, standard foot orthotics are generally of little benefit. Extra depth shoes or custom shoes may also be necessary if the shape of the foot will not for comfortably in a standard off the shelf style.
What Should I do?
Don't wait!
Any painful symptom in your arch, inside ankle area and into the inside lower part of your calf that has persisted for more than 10 days should be evaluated by your Podiatrist or Orthopedist. Catching PTTD early and getting the right treatment in place is the key to managing it effectively.
Wear supportive footwear!
The foot needs support if the muscles and tendons are weak or compromised. Going barefoot or wearing shoes with no support is very detrimental with this condition. Don't worry, the support won't make the arch weaker so you become 'dependent' on it.
Actually the forces provided by a proper support will help encourage the muscles to do their job better.
Exercise!
Strengthening the muscles in the leg can help. 20 to 30 minutes of brisk walking everyday can be very beneficial not just of your feet and legs, but the whole body!
{The information presented here is for informational purposes only and is in no way intended to replace the medical advice of your doctor. If you are experiencing discomfort in your feet for longer than 10 days to 2 weeks, seek the advice of a Podiatrist or Orthopedist.}
Stephen Sadler, C.Ped., BOCPd
Board Certified Pedorthist
InStep the Birkenstock Store, Austin, TX