Hanumanasana translates from Sanskrit as the monkey pose. Hanuman a divine entity in Hinduism is said to resemble a monkey and the pose commemorates the giant leap made by him to reach islands from the mainland of India.
This pose is quite an intense stretch and there are many variations and adaptations which have the same effect. When teaching the split I like to take it easy and I tell students to back up, when they are too ambitious. The risk of injury and overstretching a muscle or tendon is too big.
In general the muscles around the pelvis including the leg muscles tend to shorten. Sitting a lot on chairs and practicing sports like cycling shorten the hamstring, quadricep, psoas and glut muscles.
When we practice hanumanasana and its variations we should be in control of your legs and the pelvis by holding the pose with muscle strength.