Treattendonpainatthesource.

• Tendonitis is irritation or degeneration of a tendon. In the foot and ankle, the most commonly affected tendons are the Achilles, posterior tibial, peroneal, and flexor hallucis longus.
• It typically develops from overuse, sudden activity increase, biomechanical issues, or after an ankle sprain.
• Each tendon has its own specific symptom pattern — getting the exact diagnosis matters because treatments differ.
• Most cases respond to a combination of relative rest, eccentric strengthening, supportive bracing or orthotics, and PT.
• Custom orthotics and bracing address the biomechanical contributors that drive chronic tendon problems.

What is tendonitis?

Tendonitis is a general term for inflammation or degeneration of a tendon — the strong fibrous tissue that connects muscle to bone. In the foot and ankle, several different tendons can be affected, and each has its own typical pattern. Achilles tendonitis is covered on its own page. Posterior tibial tendonitis (also called posterior tibial tendon dysfunction, or PTTD) affects the tendon that supports the arch and is the leading cause of adult-acquired flatfoot. Peroneal tendonitis affects the tendons on the outside of the ankle and often follows ankle sprains. Flexor hallucis longus tendonitis affects the tendon that bends the big toe and is particularly common in dancers.

Tendonitis develops from a mismatch between load and recovery — usually some combination of sudden activity increase, repetitive overuse, biomechanical factors (foot type, gait pattern), and inadequate recovery. Chronic cases often progress from true inflammation to tendinosis, which is structural degeneration of the tendon tissue itself. This distinction matters because tendinosis responds differently to treatment than acute inflammation.

At Northwest Extremity Specialists, our sports medicine team and general podiatrists evaluate tendonitis with a focused exam to identify which tendon is involved, then build a targeted treatment plan. Conservative care — relative rest, eccentric strengthening, bracing, custom orthotics for biomechanical contributors — works for most cases. Corticosteroid injections may be considered in selected cases when conservative care alone isn't enough. Surgery is reserved for advanced cases with structural failure of the tendon.

Tendons are dense, fibrous cords that transmit force from muscle to bone. They have a relatively poor blood supply — particularly in their middle portions — which is why they heal slowly. When a tendon is overloaded, microdamage occurs faster than the tendon can repair, and inflammation (tendonitis) develops first, followed by structural degeneration (tendinosis) in chronic cases. The four most commonly affected tendons in the foot and ankle are the Achilles (back of heel), posterior tibial (inside of ankle, supports arch), peroneal (outside of ankle), and flexor hallucis longus (deep posterior, controls big toe).

What it feels like

Symptoms vary by which tendon is affected, but common features include:

• Pain along the specific tendon, worse with activity
• Tenderness when pressing directly on the tendon
• Stiffness, especially with the first steps of the day
• Swelling along the tendon path
• Weakness in the affected muscle
• Pain that's worse after activity than during it
• For posterior tibial tendonitis: arch pain and a flattening foot over time
• For peroneal tendonitis: outside-of-ankle pain and a sense of instability

Why it develops

Tendonitis develops from mechanical overload of the tendon. Common contributors:

• Sudden increase in running mileage, walking distance, or sport intensity
• Inadequate calf flexibility, which loads many lower-leg tendons
• Foot types (flat or high-arched) that overload specific tendons
• Prior ankle sprains that altered peroneal tendon function
• Worn or inappropriate footwear
• Repetitive impact on hard surfaces
• Age-related tendon degeneration (more common after 40)
• Certain medical conditions (rheumatologic diseases, fluoroquinolone antibiotics)

How we diagnose tendonitis

A tendonitis exam starts with a careful history and a focused physical exam to identify which tendon is involved. Your provider will palpate each candidate tendon, test strength, and watch your gait. On-site digital X-ray rules out bone-related causes. Ultrasound is useful for evaluating tendon thickness and tears. MRI is reserved for cases where surgical planning is being considered or where the diagnosis remains unclear. Most patients leave the same day with a tendon-specific diagnosis and a tailored plan.

Non-surgical care

Conservative care is the first line for almost every form of tendonitis. The specifics depend on which tendon is involved:

• Relative rest from the triggering activity
• Eccentric strengthening — the most evidence-based intervention for chronic tendinopathy
• Stretching of the affected muscle-tendon unit
• Tendon-specific bracing (e.g., ankle stirrup for peroneal tendonitis)
• Custom orthotics, especially when foot mechanics are contributing (posterior tibial tendonitis is a classic example)
• Physical therapy referral for guided progression
• A short course of anti-inflammatory medication for acute flares
• Corticosteroid injection in selected cases (used cautiously — repeated injections can weaken tendons)

Surgical care

Surgery is uncommon and is reserved for advanced structural failure of a tendon — significant tearing, complete rupture, or chronic tendinosis that has not responded to extensive conservative care.

• Debridement of degenerated tendon tissue
• Tendon repair for tears
• Tendon transfer (e.g., FDL to navicular for failed posterior tibial tendon)
• Release of constricting structures (e.g., for stenosing tenosynovitis)
• Combined procedures with bony realignment when foot mechanics are a contributing factor

Recovery from tendon surgery varies by procedure. Most involve 4–8 weeks in a boot, gradual return to weight-bearing, then a structured PT program. Return to running and sport is typically 4–6 months post-op.

When to see a specialist

• Foot or ankle tendon pain that has lasted more than 2 weeks despite rest and over-the-counter measures
• Pain plus a sense of weakness in the affected muscle
• A sudden "pop" with sharp pain — could be a tendon tear and needs urgent evaluation
• New arch flattening or progressive change in foot shape (suggests posterior tibial tendonitis)
• Symptoms that keep returning every time you go back to activity

Tendonitis is treated by our sports medicine team — Dr. Todd Galle in Wilsonville and Dr. Manny Moy at Cedar Mill — and by any of our board-certified podiatrists. Surgical management of advanced tendinopathy is performed by our surgical podiatrists or by Dr. Ron Bowman.

Frequently asked questions

• Achilles Tendonitis
  The most common foot/ankle tendonitis — covered in detail on its own page
• Flat Feet
  Posterior tibial tendonitis is the leading cause of adult-acquired flatfoot
• Chronic Ankle Instability
  Peroneal tendonitis often develops after recurrent ankle sprains
• Plantar Fasciitis
  Calf tightness drives both fasciitis and many tendonitis patterns