Which method is commonly used to measure flexibility?

The sit-and-reach test is widely recognized as a standard method for measuring flexibility, particularly in the lower back and hamstring regions. This test assesses how far an individual can reach forward while sitting with their legs extended. It provides a quantitative measure of flexibility that is easy to administer and requires minimal equipment—usually just a measuring tape or specialized box with a scale.

In contrast, the vertical jump test is mainly used for assessing explosive leg power and strength rather than flexibility. The plank test evaluates core stability and strength, which does not directly measure flexibility. Similarly, the curl-up test focuses on the endurance of the abdominal muscles, making it unrelated to flexibility assessment. Therefore, the sit-and-reach test is the most appropriate and commonly utilized method for evaluating flexibility.