Tight hamstrings can be a serious problem for both athletes and non-athletes alike. Individuals with tight hamstrings are at an increased risk for lower back pain and knee pain.
Most people who feel tightness in their hamstrings during activity actually have over stretched hamstrings and shortened hip flexors. Thus, many people actually need to stretch their hip flexors more than their hamstrings. See our archived hip flexor and quad stretches for more info.
Note: be sure to keep the back arched by sticking your butt out as you lean forward. Try stretching once how you'd usually do it, then try this tip. You'll really feel the difference.