Musculoskeletal: Knee Special Tests Flashcards
Ballotment Test
Why: To test for knee effusion
How: Patient is supine with knee extended. Therapist sweeps fluid toward patella and then taps on patella with the thumb.
Positive Test: Patient notes edema or fluid around or under the patella indicating edema of the knee.
Sweep/Wave/Bulge Test
Why: To test for knee effusion
How: Patient supine with knee extended. Therapist sweeps fluid around knee joint into knee joint.
Positive Test: Movement of fluid within the knee joint.
Valgus Stress Test
Why: To test the integrity of the MCL.
How: Patient is supine. Therapist grasps the lower leg at the ankle and fixates the femur. Therapist then provides a force at the knee by abducting the Tibia to stress the MCL.
Positive Test: Excessive Tibial abduction or pain in the medial knee.
Varus Stress Test
Why: To test the integrity of the LCL.
How: Patient is supine. Therapist grabs the lower leg at the ankle and stabilizes the femur. Therapist then provides an adduction force to the tibia with the femur fixed to stress the LCL.
Positive Test: Excessive tibial adduction or paint the lateral knee.
Lachman’s Test
Why: To assess the integrity of the ACL
How: Patient is supine. Therapist grabs the knee and flexes it slightly. therapist then stabilizes the Femur with one hand and applies an anterior movement to the Tibia against the femur.
Positive Test: The therapist should feel a firm end feel with anterior translation of the Tibia. If there is excessive tibial translation anteriorly this is indicative of ACL impairment.
Prone Lachman’s Test
Why: To assess the integrity of the ACL.
How: Patient is prone with femur on table. Therapist flexes patients knee and places the foot on their thigh for stability. Patient then grabs the tibia from the back and provides a posterior to anterior force at the back of the tibia to stress the ACL.
Positive Test: The therapist should feel a firm end feel with anterior translation of the Tibia on the femur. If there is excessive tibial translation anteriorly this is indicative of ACL impairment.
Anterior Drawer Test
Why: To assess the integrity of the ACL
How: Patient is supine . Therapist flexes the hip to 45 degrees and the knee to 90 degrees and stabilizes the foot on the table. Therapist then provides a sharp posterior to anterior directed force at the knee.
Positive Test: Excessive anterior tibial translation indicative of ACL impairment.
Flexion-Rotation Drawer
Why: To assess the integrity of the ACL.
How: Patient is supine. Leg is internally rotated, knee is flexed to 20 degrees. A slight valgus force is applied at the knee and the knee is moved from flexion to extension.
Positive Test: Tibia reduction posteriorly with a clunk indicates impairment to the ACL.
Posterior Drawer Test
Why: To assess the integrity of the PCL
How: Patient is supine . Therapist flexes the hip to 45 degrees and the knee to 90 degrees and stabilizes the foot on the table. Therapist then provides a sharp anterior to posterior directed force at the knee.
Positive Test: Excessive posterior tibial translation indicative of PCL impairment.
Sag Sign
Why: To assess for PCL integrity.
How: Patient is supine. Therapist flexes hip and knee to 90 degrees. Therapist grabs the patients foot by the ankle and allows gravity to pull the tibia downward observing for excessive deviation between the femur and the tibia.
Positive Test: Excessive posterior sag of the tibia toward the table in relation to the femur indicative of PCL impairment.
Sag Test
Why: To assess for the integrity of the PCL.
How: Patient is supine. Both knees are bent and next to each other with feet on the table. Therapist examines shape of anterior knee of impaired side.
Positive Test: Excessive posterior sag of the proximal anterior Tibia indicating impaired PCL integrity.
Pivot Shift Reduction and Subluxation Tests
Why: To assess for the integrity of the ACL
How: Patient lies supine with the knees extended. Therapist grabs the leg by the ankle and internally rotates the tibia. Therapist then applies a valgus force at the knee. Once both forces are applied the therapist moves the knee from extended to flexed.
Positive Test: Sudden reduction of tibia or clunking feeling in the Tibia.
Hughston External Rotational Recurvatum Test
Why: To assess for posterolateral corner instability
How: Patient is supine with knees extended. Therapist grabs the patients toes and lifts the lower extremities off the table observing for knee position.
Positive Test: If the patient exhibits posterior sag of the Tibia with external rotation.
Dial Test
Why: To assess the integrity of the PCL and posterolateral corner.
How: Patient is prone on mat table with legs extended. Therapist grabs legs by ankles and flexes the knees to 30 degrees. At 30 degrees the therapist maximally externally rotates the knees and measure the knee thigh angle. The Therapist then flexes the knees to 90 degrees and maximally externally rotates the Tibia. The therapist measures the foot, thigh angle. Both sides are compared in both positions.
Positive Test: 10 degree external rotation difference between the limbs in the 30 degree flexed position vs the 90 degree flexed position indicates possible PCL or PLC dysfunction.
Patellar Stability
Why: To assess for patellofemoral joint stability.
How: Patient is supine with knees slightly flexed. Therapist applies a laterally directed force to the patella.
Positive Test: The patient exhibits apprehension to lateral movement of the patella or reflexively tries to straighten the knee to avoid lateral patellar translation indicating patellar instability.
