Functional testing is an attempt to evaluate the knee joint
under conditions that mimic realistic functional demands. Performance
on functional tests depends on many variables, including
pain, swelling, crepitus, neuromuscular coordination,
muscular strength, and joint stability.11 The tests should be
time efficient and simple to perform with minimal instruction;
they should require minimal staff training and be conducted
within a clinical setting. Several functional knee tests are described
in the literature and include the shuttle run, stair-running
test, vertical jump test, and hop tests.10–12 These tests are
useful after ligamentous knee injuries or other sport-related
injuries, such as muscle strains or meniscus injuries, and are
not specific to the patellofemoral joint.