The sit-and-reach test is a common flexibility assessment used to measure the flexibility of the lower back and hamstring muscles. During the test, an individual sits on the floor with their legs extended straight ahead and feet against a box or measuring device. They then reach forward as far as possible, and the distance reached is recorded. This test is often included in physical fitness assessments and is useful for identifying flexibility levels. It can help individuals understand their physical condition and guide them in developing stretching routines to improve overall flexibility and reduce the risk of injury.