With the right bending forward bending occurs in the hips, and not in other parts of the body (back or knees). At all stages of motion are retained shape and length of the back. In these slopes, there are many advantages: there is no threat intervertebral discs, ligaments do not stretch the back, you will have mercy on his knees. In addition, a healthy flexion in the hip joints is a very useful exercise, because gradually stretches hamstrings each slope. However, in the early stages when the slopes, many feel a strong discomfort in the hamstrings and try to compensate for it by bending back. Ultimately, it can be bad for the spine condition.
The bending forward from a sitting tight hamstrings will pull the sitting bones to the knees, moving the pelvis in the back tilt position. The slope in this case will be carried out from the back, and not from the hip, and lumbar bending will take the form opposite to normal. If you make too much effort to reach out to the stop position to perform several times or stay in it too long, you can pull or damage to muscles, ligaments and discs of the lower back.
position of the body in the two positions allows to gently stretch the hamstring, while maintaining a neutral lumbar flexion. In the Utthita Hasta Padangushthasane height of the raised leg should be such that the basin did not take back tilt. You are lying or standing, point the tailbone and sitting bones toward the rear of the body; legs at the same time should be straight in the knees.
With daily practice of asanas hamstrings will gradually become more elastic, and you will be able to work on slopes forward without risk of damage to the lower back.