PTTD and Pronation: Understanding the Biomechanics Connection

If you’ve been diagnosed with posterior tibial tendon dysfunction (PTTD), you’ve probably heard the word “pronation” thrown around by your doctor or physical therapist. But what does it actually mean, and why does it matter for your foot health?

Understanding the relationship between pronation and PTTD can help you make better decisions about treatment and prevention. Let’s break it down in plain English.

What pronation actually is

Pronation is the natural rolling motion of your foot when you walk or stand. It’s how your body absorbs shock and adapts to different surfaces.

Here’s what happens with each step:

  1. Your heel hits the ground first
  2. Your foot rolls inward slightly (this is pronation)
  3. You push off from your toes

This inward roll is completely normal and healthy. Your foot is designed to pronate about 15% during the walking cycle. It helps distribute forces evenly across your foot and protects your joints from impact.

The problem isn’t pronation itself. It’s when pronation becomes excessive.

Normal pronation vs. overpronation

Normal pronation means your foot rolls inward about 15%, your arch compresses slightly to absorb shock, and weight distributes evenly across your foot. Shoes wear evenly, and there’s no pain.

Overpronation is different. Your foot rolls inward more than 15%, often reaching 20-30%. Your arch collapses too much, and weight shifts to the inside edge of your foot. This puts excessive stress on the posterior tibial tendon.

Think of it like a car with misaligned wheels. A little wobble is normal. But when the alignment is way off, you get uneven wear, strain on components, and eventually, problems.

How overpronation leads to PTTD

The posterior tibial tendon is the main structure that supports your arch and controls pronation. Its job is to support the arch during the middle of your step, slow down pronation so it doesn’t become excessive, and help you push off efficiently from your toes.

When you overpronate, your posterior tibial tendon works overtime. It’s constantly fighting to control that excessive inward roll. Over time, this repeated stress causes:

  1. Microtrauma — Tiny tears in the tendon from chronic overuse
  2. Inflammation — The tendon becomes irritated and swollen
  3. Degeneration — The tendon weakens and loses its structural integrity
  4. Tendinosis — Chronic degeneration without proper healing

This is why overpronation is such a common factor in PTTD. The tendon simply wasn’t designed to handle that much workload day after day.

Can you change your pronation?

The good news is that you can influence how your foot moves. Here are the main approaches:

Supportive footwear. Shoes with good arch support help limit excessive pronation. Look for motion-control shoes, stability shoes, or rocker soles for advanced cases. Avoid shoes that are too flexible in the midfoot. They let your foot roll too easily.

Orthotics. Custom orthotics are designed to address your specific biomechanics. They can support your arch more effectively, limit excessive inward rolling, and reduce strain on the posterior tibial tendon. Over-the-counter arch supports can help mild cases, but custom orthotics work better for significant overpronation.

Physical therapy. Strengthening and stretching exercises can improve foot mechanics. Focus on calf stretches (tight calves increase pronation), intrinsic foot muscle exercises to strengthen the small muscles in your feet, and hip and ankle strengthening for better overall lower limb alignment.

Gait analysis. A podiatrist or physical therapist can analyze how you walk and identify specific issues. This might involve observing your walking pattern, using pressure-sensitive mats, or video analysis of your gait. Some clinics offer 3D gait analysis for detailed biomechanical assessment.

When to get evaluated

If you notice any of these signs, it’s worth getting your pronation evaluated:

  • Frequent ankle rolling or sprains
  • Inner foot or ankle pain, especially after activity
  • Shoes that wear out on the inside edge
  • Flattening of your arch that seems to be getting worse
  • Pain that improves with supportive shoes

Early intervention can help prevent PTTD from progressing. Your doctor might recommend physical therapy, custom orthotics, activity modification, or bracing in some cases.

The bottom line

Pronation is a normal, healthy part of walking, but too much of it puts serious strain on your posterior tibial tendon. Understanding your foot biomechanics is a key part of managing PTTD or preventing it from developing.

The good news is that with the right support, you can reduce that strain and give your tendon a chance to heal.

If you’re dealing with PTTD symptoms, start with a visit to a podiatrist who can assess your biomechanics and recommend appropriate treatment. The sooner you address the underlying mechanics, the better your outcomes.

Sources

  • Biomechanics research on pronation and tendon strain
  • Clinical evidence on PTTD and foot mechanics

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of any medical condition.