"I have tight hamstrings...." is probably the #1 complaint a yoga teacher hears. The "hamstrings" is a term used to describe a group of 3 muscles found in the back of the leg that run from the sitting bones to the back of the knee. They flex the knee (think of lifting your heal up to your butt) and help the glute (butt) muscles extend the hips. But a lot of sitting, which can lead to tight and weak hip flexors, coupled with poor posture can cause stiffness and tight feeling in the hamstrings. So when you complain that your hamstrings are tight, it's often much more. Here are some tips:
Bend your knees when you try to stretch them. This helps direct the stretch to the belly of the hamstring muscles and will decrease the likelihood of aggravating the tendon attachment or insertions.
Strengthen your hip flexors. You can stretch them too but many people have weak hip flexors from not engaging in targeted muscle strengthening or having them in a state of constant tension from sitting.
Strengthen your back muscles. These are muscles that are very often neglected and have a great deal to do with correcting poor posture, which can lead to tight hamstrings.
Strengthen your butt muscles. As previously mentioned, these muscles work in tandem so if one is weak, the other tries to take over or do more of the work, creating over use and tension.
Strengthen your core, especially the lower part of your abdominals. They help the hip flexors out and do a LOT to help stabilize the back (see a pattern here?)!
Stretch your butt and your back. Tightness here can create a chain reaction in your hamstrings.
Here's a video! Enjoy!