Jacks Test (or the Hubscher maneuver) is a clinical test that is used to test the integrity of motions and forces at the first metatarsophalangeal joint and the windlass mechanism of the foot. The aim of the text is to dorsiflex the hallux while the foot is weightbearing and determine how hard the hallux is to dorsiflex and and easy it is to raise the arch of the foot during the test. This information is often used to guide interventions when there are problems with function of the joint and the integrity of the windlass mechanism at supporting the arch of the foot. It was originally described in the context of surgery for flat foot. There have been questions about the test’s validity, but it is still widely used in clinical practice.