Execution
- 1Position the patient supine with the knee flexed to approximately 90 degrees.
- 2Stabilize the foot on the table.
- 3Observe for posterior sag before contraction.
- 4Ask the patient to contract the quadriceps as if trying to slide the foot forward without moving it.
- 5Watch for anterior movement of the tibia from a posteriorly sagged position.
Positive outcome
Anterior translation of the tibia during quadriceps contraction is positive when the tibia begins in a posteriorly sagged position. The contraction pulls the PCL-deficient tibia forward toward neutral. The test must not be misread as ACL laxity.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Daniel et al. (1988) | NA | 54-98 | 97-100 | NA | NA |
CommentThe quadriceps active test is a useful rule-in adjunct for PCL injury, especially when posterior sag is visible. Reported ranges are broad because injury grade and test definition vary. The test is more meaningful when posterior drawer and sag sign support the same diagnosis.
High Clinical Value