PTTD vs Plantar Fasciitis — What’s Causing Your Foot Pain?
If you’ve been dealing with foot pain, you might have heard both terms thrown around. Honestly, it’s easy to confuse them. Both conditions cause heel and arch discomfort, they both get worse when you’re on your feet, and they can both make mornings miserable. But here’s the thing: PTTD and plantar fasciitis are completely different problems that need different treatments.
Getting the diagnosis right matters. Treat one like the other, and you could waste months on the wrong approach while the underlying issue gets worse.
The quick difference
Think of it this way:
- Posterior Tibial Tendon Dysfunction (PTTD) is a tendon problem. The posterior tibial tendon that supports your arch gets inflamed, weakens, or degenerates over time.
- Plantar fasciitis is a ligament problem. The plantar fascia, that thick band of tissue on the bottom of your foot, becomes irritated where it attaches to the heel.
Same area of the foot. Different structures. Different causes.
What is PTTD?
PTTD typically develops when the posterior tibial tendon (the tendon that runs behind your medial malleolus, that bony bump on the inside of your ankle, and attaches to the midfoot) gets overworked or starts to break down.
You’ll usually feel pain along the inside of the ankle and foot, especially when walking or standing. The tendon loses its ability to support the arch, which is why many people with PTTD notice their feet rolling inward (overpronation) and their arches collapsing over time.
Common signs include:
- Pain and swelling on the inside of the ankle
- Flattening of the arch
- Fatigue in the foot after standing or walking
- Difficulty on uneven surfaces
What is Plantar Fasciitis?
Plantar fasciitis is inflammation of the plantar fascia. It’s the tough band of tissue that connects your heel to the ball of your foot, and it’s one of the most common causes of heel pain, affecting millions of people.
The hallmark symptom? Sharp heel pain with your first steps in the morning or after sitting for a while. The pain often improves as you move around, then comes back after long periods of standing or when you stand up after resting.
Key signs include:
- Heel pain at the bottom or bottom-front of the heel
- Pain that’s worst in the morning or after rest
- Tightness in the calf or Achilles tendon
- Pain that improves with movement but returns later
How to tell them apart
Here’s where it gets tricky, because some symptoms overlap. But there are clear differences if you know what to look for:
| Feature | PTTD | Plantar Fasciitis |
|---|---|---|
| Primary pain location | Inside ankle, midfoot | Bottom of heel |
| Arch collapse | Yes, progressive flatfoot | Usually not |
| Morning pain | Stiffness, but not usually sharp heel pain | Very sharp heel pain |
| Swelling | Often visible along tendon | Usually not |
| Worsens with | Walking, standing, activities that stress the tendon | Standing after rest, first steps |
The big clue: if your arch is dropping and you’re seeing changes in your foot shape, think PTTD. If your heel hurts most in the morning and your arch looks fine, think plantar fasciitis.
Can you have both?
Actually, yes, and this is more common than you’d think.
The posterior tibial tendon and the plantar fascia both support the arch. When one is compromised, the other can take on extra stress. So it’s not unusual for someone with untreated PTTD to eventually develop plantar fasciitis, or for chronic plantar fasciitis to contribute to tendon fatigue.
This is why getting a proper diagnosis matters. A podiatrist or orthopedic specialist can examine your foot mechanics, order imaging if needed, and figure out which issue (or both) is driving your pain.
How are they treated?
PTTD treatment focuses on supporting the tendon and preventing further collapse:
- Supportive footwear with motion control
- Custom orthotics
- Physical therapy to strengthen the tendon
- Bracing or walking boots for moderate cases
- Surgery for advanced cases with tendon rupture or severe deformity
Plantar fasciitis treatment targets the inflamed fascia:
- Stretching the calf and plantar fascia
- Supportive shoes or orthotics
- Ice and NSAIDs
- Physical therapy
- Night splints
- Corticosteroid injections (in some cases)
- Surgery (rare, for chronic cases)
The treatment approaches overlap in some areas (both benefit from orthotics and physical therapy), but the underlying problem is different.
The bottom line
If you’re experiencing foot pain, don’t try to self-diagnose based on Google alone. The similarities between PTTD and plantar fasciitis make it easy to get wrong, and treating the wrong condition wastes time and money.
See a podiatrist or sports medicine doctor. Get an exam. Ask about your arch height, your gait, and what’s actually causing the pain. Once you know what you’re dealing with, you can start the right treatment and get back on your feet.
Sources
- American Academy of Orthopaedic Surgeons (AAOS) — Posterior Tibial Tendon Dysfunction
- American College of Foot and Ankle Surgeons — Plantar Fasciitis Guidelines
- Journal of Foot and Ankle Research — Comparison of adult-acquired flatfoot and plantar fasciitis