What are some key stretches for hamstring flexibility?

Some key types of stretches for hamstring flexibility are static, dynamic and PNF. With flexible hamstrings, an athlete should be able to raise a relaxed, straight leg vertically at least 90 degrees. A hamstring is tight if the leg cannot go beyond 80 degrees.

A static hamstring stretch is possible from a seated, standing or lying position. From a seated position, an athlete extends one leg straight while leaning forward. From a standing position, an athlete elevates one leg while leaning forward. From a lying position, an athlete raises a straight leg upward.

In a dynamic stretch, an athlete kicks a straight leg upward as high as possible, and in a PNF stretch, an athlete pushes a straight leg against resistance.