Tendonitis Is a Family, Not a Diagnosis
When a tendon is overloaded - whether by sudden activity, a change in footwear, a biomechanical imbalance, or chronic wear - it inflames, thickens, and starts to hurt. The location of the pain tells us which tendon is involved, and the right treatment depends entirely on that answer.
The Common Players
- Achilles tendinitis - pain in the back of the heel or 2–6 cm above it. Often worst in the morning and after rest. See Achilles tendon injuries for the full picture.
- Posterior tibial tendonitis (PTTD) - pain along the inside of the ankle and arch. The most common cause of acquired adult flatfoot. Catching it early matters; late-stage PTTD is much harder to reverse. See flat feet & PTTD.
- Peroneal tendonitis - pain along the outside of the ankle and into the foot. Common after recurrent ankle sprains.
- Anterior tibial tendonitis - pain across the front of the ankle, often from running downhill or in worn shoes.
- Flexor and extensor tendonitis - pain along the top of the foot or under the arch with toe motion.
Why Self-Treating Often Fails
Patients commonly assume any chronic foot pain is “plantar fasciitis” and buy heel cups. If the actual problem is posterior tibial tendonitis, that approach can let a treatable condition progress to a deformity that requires surgery. The first job is the right diagnosis - physical exam, gait assessment, and ultrasound or MRI when warranted.
Treatment
A graduated, evidence-based plan typically includes:
- Activity modification - not rest, but the right kind of loading.
- Eccentric strengthening - the most evidence-supported intervention for chronic tendinopathy.
- Bracing or boot immobilization for acute flares.
- Custom orthotics when biomechanics are driving the overload.
- Shockwave therapy for chronic, recalcitrant cases.
- Targeted injections in selected scenarios (used cautiously around tendons).
- Surgical reconstruction when conservative care plateaus or the tendon is structurally compromised.
When To Come In
Pain that has lasted more than a few weeks, pain that worsens with activity instead of warming up, or any sense of weakness or instability - see Dr. O’Carroll. Tendon problems are far easier to manage early than late.