| Inspection |
| Lateral patellar tracking (“J” sign; Figure 2) | Suggests patellar maltracking as a result of tight lateral restraints or VMO dysfunction |
| Poor VMO tone | May be displayed in PFPS |
| Palpation |
| Effusion | Rare in PFPS; should prompt evaluation for other causes of pain |
| Tenderness of: | |
| | Medial or lateral retinaculum | Common in PFPS; tenderness of the medial retinaculum also may be found in patellar instability |
| | Medial and lateral facets | May be found in PFPS; may indicate articular cartilage injury |
| | Patella | Usually not tender in PFPS; may indicate patellar contusion or stress reaction; can be tender in symptomatic bipartite patella; tenderness at insertion sites of quadriceps and patellar tendons can be found in tendinopathies and Sinding-Larsen-Johansson syndrome |
| | Quadriceps and patellar tendons | Suggestive of tendinopathy or tear if injury is acute |
| | Pes anserine bursa | Tenderness and swelling typical of pes anserine bursitis |
| | ITB, lateral femoral epicondyle | Suggests ITB syndrome |
| | Surface of medial or lateral femoral condyles | Direct tenderness suggests contusion or articular cartilage injury; may be tender with injuries of the collateral ligaments |
| | Infrapatellar fat pad | May be seen in Hoffa's disease |
| | Joint line | Suggests meniscal injury |
| | Plica synovialis | Nontender plicae may be found in asymptomatic knees; tenderness that reproduces symptoms denotes plica syndrome |
| Range of motion | Knee and hip range of motion usually normal in PFPS |
| Crepitus | Nonspecific finding; may occur with PFPS; can be appreciated in asymptomatic knees and those with osteoarthritis |
| Popping/clicking | Patella may produce a palpable pop, click, or clunk with palpation during passive or active range of motion; may be a sign of patellar maltracking, perhaps caused by synovial hypertrophy, plica synovialis, or cyst formation; a popping sensation with marked lateral deviation of the patella in extension indicates patellar instability |
| Patellar glide (Figure 3) | Assesses patellar mobility; displacement of less than one quadrant indicates tight lateral structures; displacement of more than three quadrants suggests patellar hypermobility caused by poor medial restraints |
| Patellar tilt (Figure 4) | Positive test (i.e., lateral aspect of patella is fixed and cannot be raised to at least horizontal position) indicates tight lateral structures |
| Patellar grind (Figure 5) | Pain with test may indicate PFPS; must be compared with contralateral knee |
| Patellar apprehension | Positive test (i.e., pain or discomfort with lateral translation of the patella) suggests lateral patellar instability as a cause of pain |
| Flexibility | Flexibility of quadriceps, hamstrings, ITB, hip flexors, and gastrocnemius should be assessed routinely |