Comprehensive Quadriceps and Knee Examination
A comprehensive quadriceps and knee examination should follow a systematic approach including inspection, palpation, range of motion testing, and specific stability tests to evaluate the integrity of ligaments, menisci, and extensor mechanism.
Initial Assessment
Inspection
- Observe patient standing, walking, and sitting
- Look for:
- Alignment (varus/valgus deformity)
- Swelling/effusion
- Muscle atrophy (especially quadriceps)
- Skin changes (bruising, scars)
- Obvious deformities
Palpation
- Always compare with the uninjured knee 1
- Palpate for:
- Joint line tenderness (medial and lateral - meniscal injury)
- Patella and patellar tendon
- Quadriceps tendon
- Femoral condyles
- Tibial plateau
- Fibular head
- Bursae (prepatellar, pes anserine)
Range of Motion Testing
Active ROM
- Flexion (normal: 135-150°)
- Extension (normal: 0-5°)
- Note any pain, crepitus, or mechanical symptoms
Passive ROM
- Assess end feel
- Compare with contralateral knee
- Note if patient can actively extend knee (inability suggests extensor mechanism disruption) 2
Stability Testing
Collateral Ligament Tests
- Valgus stress test (medial collateral ligament)
- Knee flexed 30° and in full extension
- Apply force to lateral knee while stabilizing thigh
- Varus stress test (lateral collateral ligament)
- Same positions as valgus test
- Apply force to medial knee while stabilizing thigh
Cruciate Ligament Tests
- Anterior cruciate ligament (ACL)
- Lachman test (knee flexed 20-30°)
- Anterior drawer test (knee flexed 90°)
- Pivot shift test (for rotational instability)
- Posterior cruciate ligament (PCL)
- Posterior drawer test (knee flexed 90°)
- Posterior sag sign (observe profile of knee at 90° flexion)
Meniscus Examination
- Joint line tenderness
- McMurray's test
- Flex knee fully, then extend while rotating tibia
- Click or pain indicates meniscal tear
- Apley's grind test
- Patient prone, knee flexed 90°
- Apply axial compression and rotation
Patellofemoral Assessment
- Patellar tracking
- Observe during active knee extension
- Patellar apprehension test
- Apply lateral pressure on patella with knee flexed 30°
- Patellar grind test (Clarke's sign)
- Press patella into trochlea while asking patient to contract quadriceps
Quadriceps Specific Examination
- Inspect for quadriceps atrophy (measure thigh circumference)
- Palpate quadriceps tendon for defects or tenderness
- Test quadriceps strength
- Straight leg raise test
- Resisted knee extension
- Assess for extensor lag (inability to achieve full active extension)
- Evaluate for extensor mechanism disruption 2
- Palpable defect in quadriceps or patellar tendon
- Inability to maintain extended knee against gravity
- High-riding patella (patella alta) suggests patellar tendon rupture
Special Considerations
When to Order Imaging
- Radiographs indicated if 3:
- Focal tenderness at patella or fibular head
- Inability to bear weight
- Inability to flex knee to 90°
- Age >55 years
- Gross deformity
- Suspected fracture
Common Pitfalls
- Failing to compare with the uninjured knee
- Not adequately relaxing the patient during ligament testing
- Misinterpreting joint effusion as soft tissue swelling
- Overlooking subtle extensor mechanism disruptions
- Focusing only on the primary complaint while missing associated injuries
By systematically following this examination approach, clinicians can accurately diagnose knee pathologies and determine appropriate management strategies to optimize patient outcomes.