When an athlete feels better, we often assume they’re getting better structurally too.
But what if that’s not always the case?
A 2018 study from van Ark, Rio, Cook, and colleagues challenges a long-standing assumption in the treatment of patellar tendinopathy: that reducing pain and improving function should be accompanied by structural improvements in the tendon.
Here’s what they found, why it matters, and how it should influence your coaching and rehab decisions.
Why it Matters
Patellar tendinopathy, or jumper’s knee, is a common issue for athletes in sports like basketball and volleyball.
It can limit training, performance, and even lead to long-term issues if not addressed.
We often use imaging, especially ultrasound, to confirm the diagnosis and monitor progress.
But newer tools like ultrasound tissue characterization (UTC) go a step further, allowing us to see the organization of tendon fibers, not just the size or shape of the tendon.
This study asked a key question:
Can athletes with patellar tendinopathy feel better without seeing improvements in tendon structure?
The Training
The researchers recruited 29 basketball and volleyball players (ages 16–31) diagnosed with patellar tendinopathy.
Each athlete completed a 4-week in-season loading program of either:
- Isometric training: 5 sets of 45s holds at 80% MVC, or
- Isotonic training: 4 sets of 8 reps with 3s concentric / 4s eccentric, also at 80% of 8RM.
Both groups trained four times per week and were matched for time under tension and progression.
UTC scans and clinical outcome measures were taken at baseline and after 4 weeks.
The Changes
Pain went down
- Pain during single-leg decline squat (NRS) dropped from 6.0 → 2.3
- VISA-P scores (patellar tendinopathy function questionnaire) improved from 67.5 → 81.5
Tendon structure stayed the same
UTC measures showed no change in:
- Aligned fibrillar tissue (healthy structure)
- Disorganized tissue (damaged structure)
- Cross-sectional area (CSA)
- Tendon thickness
Whether they did isometric or isotonic training, the structure didn’t budge.
And yet, the pain subsided, and function improved.
Pain Reduction ≠ Structure Fixed
The tendon’s appearance didn’t change, but its behavior did.
There are a few potential reasons or explanations:
1. Load tolerance improved
The aligned fibers that were already there may have become more load-tolerant.
The tendon didn’t need to “rebuild” itself, it just needed to work better under stress.
2. Central nervous system adaptation
Isometric contractions have been shown to reduce cortical inhibition and provide pain relief.
The nervous system may be recalibrating sensitivity, not the tendon itself.
3. Rehab focused on capacity, not healing
This supports a growing idea in rehab: pain is not always a sign of tissue damage, and healing is not required for function to improve.
Takeaway for Coaches and Clinicians
Don’t let imaging dictate return-to-play decisions
Just because a tendon still looks pathological doesn’t mean the athlete isn’t ready to progress.
Focus on functional metrics
Pain scores, strength, jump capacity, and performance markers are better indicators of progress than whether the tendon looks more aligned on a scan.
Structural healing may take longer (or may never occur)
Some research suggests that tendon remodeling is a slow process, possibly taking months or years.
This doesn’t mean your intervention isn’t working; it means structure doesn’t always drive symptoms.
Reference
van Ark, M., Rio, E., Cook, J., et al. (2018). Clinical Improvements Are Not Explained by Changes in Tendon Structure on Ultrasound Tissue Characterization After an Exercise Program for Patellar Tendinopathy. American Journal of Physical Medicine & Rehabilitation, 97(10), 708–714. Link to Pubmed
