Deep Hamstring Work This is a strong vinyasa flow class that focuses mostly on the hamstrings. Straight legged poses are more challenging than one might think. That is because it is very important never to lock out the knees. This will unduly burned the ligaments surrounding the knees and lead to hyperextension and weak joints. When we straighten our legs, we want to do it by using the musculature above the knees, mostly the quadriceps. It is also important to notice when you are rounding to go deeper in forward folds. An overly rounded fold is bad form and puts a lot of extra strain on the lumbar spine. As our practice deepens we are more mindful not just about where we stretch but how we stretch. A good opening of the hamstrings will allow for more range of motion in the pelvis and reduce stress felt in the lower back.