Patellar Tendonitis vs Patellofemoral Pain Syndrome: Below vs Behind the Kneecap
Understanding the key differences between Patellar Tendonitis and Patellofemoral Pain Syndrome
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⚡ Quick Summary
Patellar tendonitis = pain BELOW the kneecap at the tendon (jumping sports, treated with eccentric decline squats — pain during exercise acceptable). PFPS = pain AROUND/BEHIND the kneecap at the joint surface (running sports, treated with hip strengthening — not knee exercises). Key location test: press at inferior pole of patella for tendonitis; press around/under the kneecap for PFPS. Both rarely need surgery; the right rehabilitation works.
Overview
[Patellar tendonitis (jumper's knee)](/condition/patellar-tendonitis) and [patellofemoral pain syndrome (runner's knee)](/condition/patellofemoral-pain-syndrome) are two of the most common athletic knee injuries — and they affect different structures despite similar names. The key location distinguishes them: patellar tendonitis affects the TENDON BELOW the kneecap, while PFPS affects the JOINT BEHIND the kneecap. Treatment differs significantly: patellar tendonitis requires eccentric tendon loading, while PFPS responds to hip strengthening.
Key Differences at a Glance
| Feature | Patellar Tendonitis | Patellofemoral Pain Syndrome |
|---|---|---|
| Pain Location | BELOW the kneecap — at the inferior pole of the patella where the patellar tendon attaches; well-localized to a specific bony point | AROUND or BEHIND the kneecap — at the joint surface; more diffuse "deep" pain |
| Structure Affected | PATELLAR TENDON — connects kneecap to shinbone; degenerative changes in the tendon (tendinopathy) | PATELLOFEMORAL JOINT — where the kneecap meets the femur; tracking dysfunction; not a tendon issue |
| Sports Most Affected | JUMPING sports — volleyball (40-50% career prevalence), basketball, track and field, soccer (kicking) | RUNNING sports — running (22-40% of runners), cycling, cutting/pivoting sports; very common in young women |
| Specific Pain Triggers | JUMPING, SPRINTING, KICKING — explosive movements that load the tendon; deep squatting; stair descent | STAIR climbing (especially descending), SQUATTING, PROLONGED SITTING ("movie sign"), running |
| Diagnostic Test | DIRECT PALPATION of the inferior pole of patella reproduces pain; decline single-leg squat test | Patellar grind test (Clarke's sign), apprehension test; single-leg squat shows knee valgus |
| Cornerstone Treatment | ECCENTRIC DECLINE SQUATS — 12-week protocol; pain during exercise acceptable; targets tendon healing | HIP STRENGTHENING — clamshells, side leg raises (not knee exercises); addresses underlying biomechanics |
| Sex Distribution | MEN 2x more affected (in same sports) | WOMEN 2x more affected (anatomic and biomechanical reasons) |
Symptoms Comparison
Symptoms Both Share
- • Anterior knee pain related to athletic activities
- • Pain with stair climbing
- • Pain with squatting
- • Both common in young athletes
- • Both can become chronic without proper treatment
- • Both improve with appropriate rehabilitation
- • Both rarely need surgery (<5-10% of cases)
Patellar Tendonitis Specific
- • Pain BELOW the kneecap at the patellar tendon
- • Direct tenderness on inferior pole of patella
- • Pain especially with JUMPING and KICKING
- • Reduced jumping/sprinting performance
- • Pain that may INCREASE during activity in advanced stages
- • Subtle swelling at the patellar tendon
- • Stage classification (Blazina) describes severity
Patellofemoral Pain Syndrome Specific
- • Pain AROUND or BEHIND the kneecap
- • "Movie sign" — pain with prolonged sitting that improves with knee extension
- • Pain especially with STAIR DESCENDING
- • Crepitus (clicking) under the kneecap
- • Often bilateral (both knees)
- • Sense of knee "giving way" from pain inhibition
- • Develops gradually over weeks/months
Causes
Patellar Tendonitis Causes
- • Repetitive jumping in sports (volleyball, basketball, track)
- • Sudden increase in training volume (>10% per week)
- • Eccentric loading during landing
- • Tight quadriceps increasing tendon tension
- • History of Osgood-Schlatter disease (40-50% of cases)
- • Hard playing surfaces
- • Male sex (2x risk in same sports)
Patellofemoral Pain Syndrome Causes
- • Hip weakness — especially gluteus medius (80-90% of cases)
- • Quadriceps imbalances and VMO weakness
- • Excessive foot pronation
- • High Q angle (anatomic) — wider in women
- • Sudden increase in training volume
- • Tight IT band, hamstrings, hip flexors
- • Female sex (2x risk)
Treatment Options
Patellar Tendonitis Treatment
- ✓ ECCENTRIC DECLINE SQUATS — 3 sets of 15, twice daily, 12 weeks (gold standard)
- ✓ Reduce sport activity 50-70% during recovery
- ✓ Cho-Pat patellar tendon strap
- ✓ Quadriceps and hamstring stretching
- ✓ Hip strengthening as adjunct
- ✓ AVOID corticosteroid injection into tendon (rupture risk)
- ✓ Shockwave therapy for chronic cases
Patellofemoral Pain Syndrome Treatment
- ✓ HIP STRENGTHENING — clamshells, side-lying leg raises (THE cornerstone)
- ✓ Quadriceps strengthening with closed-chain exercises
- ✓ IT band and hamstring stretching
- ✓ Activity modification — avoid deep squats
- ✓ Patellar taping or bracing
- ✓ Foot orthotics for excessive pronation
- ✓ Avoid corticosteroid injections (limited evidence)
How Long Does It Last?
Patellar Tendonitis
Acute cases: 4-8 weeks. Chronic tendinopathy: 3-6 months minimum with proper eccentric exercise. 70-80% improve with conservative treatment. Surgery rare (<10%).
Patellofemoral Pain Syndrome
70-90% improve within 6-12 weeks of structured rehabilitation. Without proper hip-focused treatment, 30-50% become chronic. Surgery rarely needed (<5%).
When to See a Doctor
Seek medical attention if you experience any of the following:
- ⚠️ Knee pain lasting more than 4-6 weeks despite home treatment
- ⚠️ Sudden severe pain with inability to extend knee (possible tendon rupture)
- ⚠️ Pain limiting your sport performance significantly
- ⚠️ Pain at rest or at night
- ⚠️ Mechanical symptoms (catching, locking)
- ⚠️ Recurrent symptoms despite previous treatment
- ⚠️ Inability to perform daily activities like stairs
Frequently Asked Questions
Frequently Asked Questions about Patellar Tendonitis vs Patellofemoral Pain Syndrome
Click on a question to see the answer.
Yes — and they can coexist, especially in athletes who do both jumping and running sports. **Co-occurrence is common** because: 1) Both are overuse injuries from cumulative training stress, 2) Hip weakness underlies both conditions, 3) Years of repetitive activity stresses multiple knee structures simultaneously. **When both are present**, treatment addresses both — eccentric decline squats for [patellar tendonitis](/condition/patellar-tendonitis), hip strengthening for [PFPS](/condition/patellofemoral-pain-syndrome), and addressing each condition's specific contributors. The good news is that hip strengthening helps both conditions, and load management benefits both.
Different activities load different structures. **Jumping** creates intense eccentric loading on the [patellar tendon](/condition/patellar-tendonitis) during landing — explaining the pain BELOW the kneecap. **Running** involves repetitive knee flexion-extension under load that affects the [patellofemoral joint](/condition/patellofemoral-pain-syndrome) — explaining the pain BEHIND the kneecap. Activity-specific symptoms are useful diagnostic clues. If you're a multi-sport athlete with both pain patterns, you may have both conditions and need a comprehensive treatment plan addressing each.
The **decline squat (25-30° decline board) on a single leg** is uniquely effective because: 1) **Isolates the patellar tendon** — the decline angle increases tendon strain by ~25%, focusing healing where needed, 2) **Eccentric loading** stimulates collagen remodeling and tendon adaptation, 3) **Pain during exercise is therapeutic** — controlled microtrauma triggers healing (up to 4/10 pain is acceptable). Studies show 60-90% success rates with 12-week protocols (3 sets of 15 reps, twice daily). Flat surface squats are less effective for tendon healing — the decline angle is critical. This is the Curwin-Stanish protocol for [patellar tendinopathy](/condition/patellar-tendonitis).
Medical Disclaimer
The information on this page is for educational purposes only and is not intended as medical advice. It should not be used for self-diagnosis or self-treatment. Always seek the guidance of a qualified healthcare professional with any questions you have regarding a medical condition. If you are experiencing a medical emergency, call your local emergency services immediately.