Potential nervous system sensitization in patients with persistent lower extremity tendinopathies: 3 case reports

Key points

1. 01All three patients had failed at least two prior evidence-based treatment courses lasting 4 to 22 months before this intervention
2. 02A multimodal approach targeting both peripheral and central pain mechanisms was used: joint mobilization, pain neuroscience education, and aerobic exercise
3. 03Pain pressure thresholds at the involved tendon improved by an average of 169%, and remote site readings also improved, suggesting widespread pain modulation
4. 04All patients were able to run without symptoms at discharge and remained symptom free at one-year email follow up
5. 05Central Sensitization Inventory scores and reduced remote pain pressure thresholds were used to identify a possible central sensitization component

How it was conducted

Design

Retrospective case series (Level 4 evidence)

Participants

3 patients with persistent lower extremity tendinopathy (2 Achilles, 1 patellar) lasting 18 months to 4 years, each having failed multiple prior treatment courses

Intervention

5 sessions over 8 weeks: joint mobilization, pain neuroscience education, and self-selected moderate-to-high intensity aerobic exercise 4+ days per week

Primary outcomes

Numeric Pain Rating Scale (NPRS), VISA-A or VISA-P self-reported disability, and pain pressure thresholds (PPT) at the involved tendon, contralateral tendon, and contralateral thenar eminence

Follow-up

One-year email follow-up for symptom status

What they found

• PPT at the involved tendon improved by an average of 169% across the three patients
• PPT at the contralateral tendon improved by an average of 126%
• PPT at the contralateral hand improved by an average of 46%
• All three patients achieved the ability to run at least 30 minutes without symptom aggravation by session 5
• All three patients reported being symptom free with no functional limitation at one-year follow-up
• 100% compliance with the home exercise program was reported by each patient

Limitations

• Very small sample of 3 patients with no control group prevents any causal conclusions
• Multimodal treatment design makes it impossible to attribute benefit to any single intervention
• Order effects or acclimation to pain pressure threshold testing cannot be excluded
• Minimal clinically important difference for PPT in lower extremity tendinopathy has not been established, limiting interpretation of PPT changes

Why it matters

For patients

Patients with tendon pain that keeps returning despite standard exercises may benefit from an approach that also addresses how the nervous system processes pain, including education about pain biology and regular aerobic exercise.

For clinicians

When patients with chronic lower extremity tendinopathy fail repeated evidence-based loading programs, screening for central sensitization features using tools such as the CSI and remote PPT testing, then incorporating pain neuroscience education and aerobic exercise, may improve outcomes.

For readers

This case series adds preliminary clinical support to emerging evidence linking nervous system sensitization with persistent tendinopathy, but higher-quality controlled trials are needed before this approach can be recommended as standard practice.