Execution
- 1Palpate the peripatellar region and record whether familiar tenderness is present.
- 2Ask the patient to perform a squat.
- 3Record whether the squat reproduces familiar anterior knee pain.
- 4Count the cluster positive when palpation tenderness and squat pain are present.
- 5Screen for tendon, meniscus, OA, and instability signs before labeling PFPS.
Positive outcome
The cluster is positive when peripatellar palpation tenderness and squat pain are both present. It supports a PFPS classification, not a cartilage-specific diagnosis. Pain location and exclusion of other anterior knee pain generators are important.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Cook et al. (2010) | NA | NA | NA | NA | NA |
| Cook et al. (2012) | systematic review | NA | NA | NA | NA |
CommentCook's clusters are more useful than Clarke's sign or isolated functional pain tests. The exact cluster names are not universal, so the components are explicitly listed here. Interpret as diagnosis support for PFPS, not a definitive cause of symptoms.
High Clinical Value