It can often seem like there are two kinds of people in the world – flexible people and those who… well, aren’t. This distinction seems especially noticeable when you fall into the “not flexible” camp. So what’s the deal? What are the causes of tight hamstrings? How can I improve my flexibility? There’s a few factors that contribute to a lack of hamstring flexibility, such as: Truly tight hamstrings Prior injuries Decreased back/pelvis mobility Overwork Improper training So l