What is the likely diagnosis and recommended management for a 57-year-old active female with several months of left ankle and Achilles‑tendon pain and stiffness that worsens after prolonged rest (e.g., sitting for an hour in the morning) and improves with walking?

Likely Diagnosis and Management

This is most likely insertional Achilles tendinopathy, a degenerative condition (not inflammation) that characteristically causes morning stiffness and pain after rest that improves with activity—exactly matching this patient's pattern. 1, 2

Why This Diagnosis Fits

The clinical picture is classic for Achilles tendinopathy:

• Pain and stiffness after prolonged rest (sitting for an hour, getting out of bed in the morning) that improves with walking is the hallmark presentation 2, 3
• No pain during normal activities (walking 3 miles, gym, Pilates) indicates the tendon can handle load once "warmed up" 1, 4
• Insidious onset over several months in an active 57-year-old woman fits the typical demographic and presentation 1, 4
• The location (Achilles tendon and ankle area) points to insertional tendinopathy affecting the tendon's attachment to the heel bone 1

Critical Understanding: This Is Degenerative, Not Inflammatory

The underlying pathology is degenerative tendinopathy (tendinosis), not acute inflammation (tendinitis)—this distinction fundamentally changes treatment approach. 4, 5, 6 The tendon has undergone failed healing with collagen disorganization, increased glycosaminoglycans, and neovascularization rather than inflammatory cell infiltration 5, 6.

Initial Treatment Plan (First 6-8 Weeks)

Start with these conservative measures immediately:

• Open-backed shoes to reduce pressure on the Achilles insertion 1
• Heel lifts or orthoses to decrease strain on the tendon 1
• NSAIDs (oral or topical) for pain relief—topical formulations avoid gastrointestinal side effects 1
• Eccentric calf strengthening exercises—this is the single most evidence-based effective treatment and can reverse degenerative tendon changes 2, 3, 5
• Stretching exercises for the calf and Achilles 1
• Relative rest and activity modification—continue low-impact activities but avoid sudden increases in training intensity 4, 5

Critical pitfall: Do NOT inject corticosteroids into or near the Achilles tendon—this is explicitly contraindicated due to risk of tendon rupture. 1

If No Improvement After 6-8 Weeks

Escalate to:

• Referral to a podiatric foot and ankle surgeon for specialized evaluation 1
• Immobilization cast or fixed-ankle walker device for more refractory cases 1
• Extracorporeal shock wave therapy—safe, noninvasive, and evidence-based for chronic tendinopathy, though expensive 2, 3
• Glyceryl trinitrate (nitric oxide) patches if symptoms persist 2, 3

If No Improvement After 6 Months

• Surgical intervention should be considered only after a full 6-month trial of conservative treatment 2, 3
• Surgery involves excision of degenerative tissue and release of scarred areas 1

What to Examine and Monitor

On physical examination, look for:

• Tenderness at the Achilles insertion (where tendon meets heel bone) that reproduces her pain 1
• Prominence or thickening medially and laterally to the Achilles insertion 1
• Swelling in the posterior heel area 1, 2

Imaging is not immediately necessary for typical presentations, but if symptoms don't improve or diagnosis is uncertain: 1

• Plain radiographs can show spurring or erosion at the Achilles insertion 1
• Ultrasound or MRI can confirm tendon pathology and rule out other diagnoses 2, 3

Expected Timeline

• Most patients (approximately 80%) achieve full functional recovery within 3-6 months with conservative treatment 7, 5
• Complete normalization of tendon strength often takes longer than symptom resolution 7
• The morning stiffness pattern should gradually improve as the tendon heals 2, 3

Key Pitfalls to Avoid

• Do not label this as "tendinitis" or treat it primarily as inflammation—anti-inflammatory treatments alone will fail because the underlying problem is degeneration 4, 5
• Avoid complete immobilization as it leads to muscle atrophy and deconditioning 7
• Do not allow her to "push through" severe pain—this can worsen degenerative changes 4
• If multiple tendons become symptomatic, evaluate for underlying rheumatic disease 7