Knee special tests
When a PTA performs these tests as part of data collection under the plan of care, a new or changed positive finding is reported to the supervising PT, who interprets it and decides whether to re-evaluate.
- Lachman test
- Patient supine with knee flexed to 20-30 degrees; stabilize the femur and passively translate the tibia anteriorly
- Tests the integrity of the anterior cruciate ligament
- Positive: excessive anterior translation of the tibia compared to the uninvolved limb
- Patient supine with knee flexed to 20-30 degrees; stabilize the femur and passively translate the tibia anteriorly
- Anterior drawer test
- Patient supine with hip flexed to 45 degrees and knee flexed to 90 degrees; therapist passively translates the tibia anteriorly
- Tests the integrity of the anterior cruciate ligament
- Positive: excessive anterior translation of the tibia compared to the uninvolved limb
- Patient supine with hip flexed to 45 degrees and knee flexed to 90 degrees; therapist passively translates the tibia anteriorly
- Posterior drawer test
- Patient in supine with hip flexed to 45 degrees and knee flexed to 90 degrees; therapist passively translates tibia posteriorly
- Tests the integrity of the posterior cruciate ligament
- Positive: excessive posterior translation of the tibia compared to the uninvolved limb
- Patient in supine with hip flexed to 45 degrees and knee flexed to 90 degrees; therapist passively translates tibia posteriorly
- Valgus stress test
- Patient supine with knee resting at the edge of the mat; therapist applies valgus stress to the knee with the knee flexed at 0 and 30 degrees
- Tests the integrity of the medial collateral ligament
- Positive: laxity and pain compared to the uninvolved side
- Laxity at 30° isolates the collateral ligament; laxity at 0° (full extension) suggests the cruciates and capsule are also involved.
- Patient supine with knee resting at the edge of the mat; therapist applies valgus stress to the knee with the knee flexed at 0 and 30 degrees
- Varus stress test
- Patient supine with knee resting at the edge of the mat; therapist applies varus stress to the knee with the knee flexed at 0 and 30 degrees
- Tests the integrity of the lateral collateral ligament
- Positive: laxity and pain compared to the uninvolved side
- Laxity at 30° isolates the collateral ligament; laxity at 0° (full extension) suggests the cruciates and capsule are also involved.
- Patient supine with knee resting at the edge of the mat; therapist applies varus stress to the knee with the knee flexed at 0 and 30 degrees
- Pivot shift test
- Patient supine, knee extended, hip slightly flexed and abducted; therapist internally rotates the tibia, applies a valgus force, and flexes the knee
- Tests the integrity of the anterior cruciate ligament
- Positive: a clunk at about 30-40 degrees of flexion as the anteriorly subluxed lateral tibial plateau is pulled back into place by the iliotibial band
- The test is highly specific for ACL deficiency, but it is hard to perform on an acutely injured knee because anticipated pain triggers protective hamstring guarding, which lowers its sensitivity
- Patient supine, knee extended, hip slightly flexed and abducted; therapist internally rotates the tibia, applies a valgus force, and flexes the knee
- McMurray test
- Patient supine with knee maximally flexed; therapist passively internally rotates and extends the knee, then moves to externally rotating and extending the knee
- Tests the lateral meniscus (internal rotation) and the medial meniscus (external rotation)
- Positive: reproduction of click, popping, or pain in the knee
- Patient supine with knee maximally flexed; therapist passively internally rotates and extends the knee, then moves to externally rotating and extending the knee
- Apley’s compression test
- Patient positioned prone with the knee flexed to 90 degrees. The therapist applies a downward compressive force through the heel while medially and laterally rotating the tibia.
- Tests the integrity of the menisci of the knee
- Positive: reproduction of pain
- Patient positioned prone with the knee flexed to 90 degrees. The therapist applies a downward compressive force through the heel while medially and laterally rotating the tibia.
- Thessaly test
- Patient standing on involved leg while holding therapist’s hands; patient rotates body and leg internally and externally with knee flexed to 5 degrees and then at 20 degrees
- Tests the lateral meniscus (internal rotation) and the medial meniscus (external rotation)
- Positive: reproduction of click, popping, or pain in the knee
- Patient standing on involved leg while holding therapist’s hands; patient rotates body and leg internally and externally with knee flexed to 5 degrees and then at 20 degrees
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Patellar apprehension test
- Patient supine with knee flexed to 30 degrees and quadriceps relaxed; therapist passively translates the patella laterally
- Test for patellar instability
- Positive: patient expresses apprehension or contracts the quadriceps muscle to prevent patellar dislocation
- Patient supine with knee flexed to 30 degrees and quadriceps relaxed; therapist passively translates the patella laterally
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Noble compression test
- Patient supine with knee flexed to 90 degrees and hip flexion; therapist applies pressure 1-2cm proximal to the lateral femoral epicondyle; with pressure maintained, the patient’s knee is passively extended
- Tests the iliotibial band
- Positive: patient experiences pain over the lateral femoral condyle
- Patient supine with knee flexed to 90 degrees and hip flexion; therapist applies pressure 1-2cm proximal to the lateral femoral epicondyle; with pressure maintained, the patient’s knee is passively extended
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Ober test
- Patient side-lying with the test leg uppermost; therapist abducts and extends the hip with the knee flexed to 90 degrees, stabilizes the pelvis, then slowly lowers the leg toward the table
- Tests for iliotibial band tightness or contracture
- Positive: the leg remains abducted and does not lower to the table
- Patient side-lying with the test leg uppermost; therapist abducts and extends the hip with the knee flexed to 90 degrees, stabilizes the pelvis, then slowly lowers the leg toward the table
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Stroke (sweep) test
- Patient supine with knee extended; therapist strokes fluid from the medial side of the knee upward, then strokes the lateral side downward
- Tests for minor knee joint effusion
- Positive: a wave or bulge of fluid reappears on the medial side of the knee
- Patient supine with knee extended; therapist strokes fluid from the medial side of the knee upward, then strokes the lateral side downward
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Ottawa knee rules
- Screen for fracture after acute knee injury. Any one positive criterion below means imaging is indicated to rule out a fracture, so the PTA reports it to the supervising PT, who follows up on imaging. If all five are negative, a fracture is very unlikely and imaging is generally not needed.
- Age 55 years or older
- Isolated tenderness of the patella (no bone tenderness of the knee other than at the patella)
- Tenderness of the fibula head
- Inability to actively flex knee to 90 degrees
- Inability to bear weight (take 4 steps), both immediately after the injury and at the time of examination
- Screen for fracture after acute knee injury. Any one positive criterion below means imaging is indicated to rule out a fracture, so the PTA reports it to the supervising PT, who follows up on imaging. If all five are negative, a fracture is very unlikely and imaging is generally not needed.