Reading time: 12 minutes | Last updated: May 2026
Patellar tendinitis — also called jumper’s knee — is one of the most common injuries in strength sport across the Netherlands, Scandinavia, and Europe. Scandinavian sports science has produced the most rigorous research on patellar tendinopathy treatment, including the Alfredson eccentric protocol and the Kongsgaard heavy slow resistance protocol. This guide covers the complete evidence-based approach used by European physiotherapists.
Table of Contents
- What’s Actually Happening
- Symptoms & Diagnosis
- Why Squatters Get Patellar Tendinitis
- Phase 1: Isometric Loading — Immediate Pain Relief
- Phase 2: Eccentric Loading — The Decline Squat Protocol
- Phase 3: Heavy Slow Resistance — The Kongsgaard Protocol
- Load Management During Rehab
- How Footwear Affects Patellar Tendinitis
- Prevention Protocol
- Green, Amber, Red
- Bottom Line
- FAQ
🦴 What’s Actually Happening
Patellar tendinitis is tendinopathy of the patellar tendon — the tendon connecting the kneecap (patella) to the tibia. It’s not inflammation in the traditional sense but a failed healing response causing structural changes in the tendon. Research from the Scandinavian Journal of Medicine & Science in Sports — where much of the foundational patellar tendinopathy research originates — confirms that eccentric and heavy slow resistance loading drives tendon remodelling and is the most effective conservative treatment.
🔍 Symptoms & Diagnosis
- ✅ Pain directly below the kneecap, at the top of the patellar tendon
- ✅ Worse on the descent phase of the squat (eccentric loading)
- ✅ Worse after prolonged sitting (stiffness that improves with movement)
- ✅ Tender on palpation at the inferior pole of the patella
- ✅ No swelling or instability
⚠️ Why Squatters Get Patellar Tendinitis
- 🚨 Rapid volume increases — adding squat volume faster than the tendon can adapt
- 🚨 High-frequency squatting without adequate recovery
- 🚨 Weak quadriceps — the tendon compensates for insufficient quad strength
- 🚨 Tight quadriceps — increases patellar tendon load
- 🚨 Hard training surfaces — increases impact loading on the tendon
🛠️ Phase 1: Isometric Loading — Immediate Pain Relief
Research published in the British Journal of Sports Medicine by Rio et al. confirms isometric contractions provide immediate cortical pain inhibition — reducing patellar tendon pain by up to 40% for 45 minutes post-exercise. Used by European sports medicine practitioners as a pre-training pain management tool.
- 📌 Isometric wall sit: 60° knee flexion, 5 x 45 seconds. Before every training session. Provides immediate pain relief and maintains quad stimulus.
- 📌 Leg press isometric hold: 70% of 1RM, 5 x 45 seconds. Alternative to wall sit.
Duration: Use Phase 1 for the first 2–4 weeks, or whenever pain is above 4/10 before training.
🛠️ Phase 2: Eccentric Loading — The Decline Squat Protocol
The decline single-leg squat is the gold standard rehabilitation exercise for patellar tendinopathy — developed and validated through Scandinavian research and now standard across European physiotherapy practice.
- 📌 Decline single-leg squat: 25° decline board, slow 4-second lowering, 3 x 15 each side. 3x/week (not daily — tendons need 48hr recovery).
- 📌 Progress load: Add a weight vest or hold a dumbbell as pain allows.
- 📌 Pain during the exercise is acceptable up to 4/10 — this is the Alfredson protocol principle. Pain above 5/10 = reduce range or load.
Duration: 6–12 weeks. Consistency is the key variable.
🛠️ Phase 3: Heavy Slow Resistance — The Kongsgaard Protocol
The Kongsgaard heavy slow resistance (HSR) protocol — developed at the University of Copenhagen — has been shown to outperform the Alfredson eccentric protocol at 12-month follow-up in multiple European studies.
- 📌 Leg press: 3 x 15 at 55% 1RM, progressing to 4 x 6 at 85% 1RM over 12 weeks. Slow tempo (3 seconds up, 3 seconds down).
- 📌 Hack squat or leg press: Same protocol. 3x/week.
- 📌 Squats (when pain allows): Slow tempo, full range. Progress load weekly.
Duration: 12 weeks. This is the most evidence-based protocol for chronic patellar tendinopathy.
🛠️ Load Management During Rehab
- 📌 Reduce squat volume 40–50% during Phase 1 and early Phase 2.
- 📌 Avoid high-load eccentric squatting (box jumps, plyometrics) until Phase 3.
- 📌 Monitor the 24-hour response — pain higher next day = reduce load.
- 📌 Continue upper body and hip-dominant lower body training throughout.
👟 How Footwear Affects Patellar Tendinitis
A weightlifting shoe with heel elevation reduces ankle dorsiflexion demand, allowing a more upright torso and reducing the eccentric quad load on the patellar tendon during the descent. For European lifters with patellar tendinitis, heel elevation can allow continued squatting at reduced pain levels while the tendon rehabilitates. Free EU shipping, no import costs.
Patellar tendinitis limiting your squat? A heel elevation can reduce tendon load and allow continued training during rehabilitation.
🛡️ Prevention Protocol
- Isometric wall sits before every squat session.
- Decline single-leg squats 3x/week as maintenance.
- Never increase squat volume more than 10% per week.
- Quad stretching daily — 2 x 60 seconds each side.
- Deload every 4–6 weeks.
🚦 Green, Amber, Red
| Signal | What It Means | Action |
|---|---|---|
| 🟢 Pain 0–3/10, resolves during warm-up | Manageable tendinopathy | Train. Isometrics before session. Decline squats 3x/week. |
| 🟡 Pain 4–6/10, consistent | Active tendinopathy | Reduce squat volume 40–50%. Phase 1 isometrics. See a physiotherapist. |
| 🔴 Swelling, instability, or pain 7+/10 | Possible structural issue | Stop. See a sports medicine physician. |
🏆 Bottom Line
Patellar tendinitis from squatting responds to a phased loading protocol — isometrics first for pain relief, then decline squats for eccentric loading, then heavy slow resistance for full tendon remodelling. Scandinavian research developed the protocols that European physiotherapists now prescribe. Expect 6–12 weeks for significant improvement. Don’t rest completely — tendons need load to heal.
Load the tendon. Heal the tendon. Keep squatting.
Knee Pain When Squatting — Europe → IT Band Syndrome — Europe →FAQ
What is the best exercise for patellar tendinitis from squatting?
Decline single-leg squat — 3 x 15 each side, 3x/week. The gold standard rehabilitation exercise validated by Scandinavian research. Preceded by isometric wall sits for immediate pain relief.
How long does patellar tendinitis take to heal?
6–12 weeks with consistent protocol. Chronic cases (6+ months): 3–6 months. Complete rest slows healing — load the tendon.
What is the Kongsgaard protocol?
Heavy slow resistance protocol developed at the University of Copenhagen. Shown to outperform the Alfredson eccentric protocol at 12-month follow-up. Full protocol above.
Where can I find a physiotherapist in the Netherlands or Scandinavia?
Netherlands: covered under basic health insurance with GP referral. Norway/Sweden/Denmark: national health system or private clinics. Search “sportsfysioterapeut” locally.
Related Articles
- Knee Pain When Squatting — Europe
- IT Band Syndrome from Squatting — Europe
- Tight Hip Flexors & Squatting — Europe
Written by T-K — Creative Director & Brand Strategist, Castiron Lift.