In this exercise, there is a simpler analogue: pulling the knees to the chest from a prone position. Your task - to "curl" to the shoulders, without lifting the shoulder blades off the floor; as if you want to do a somersault backwards. Please note that if you do the exercise too hard, you will begin to sway from side to side. Do not forget to hold her arms to avoid it.
Practice lifting the legs from different positions. Is a very effective training on uneven bars: raise the legs should be long until they are parallel to the ground (in any case not more than - you can lose your balance and get injured). In this exercise, your hands have to an additional burden: to compensate for it, should not rest on the bars with his hands, and elbows, if possible.
The best exercises for the development of the lower press is raising the legs straight out of Davis on the crossbar. It is extremely important that the hands were completely relaxed: if you bend them slightly, the exercise will be given easier, but at the expense of other muscle groups. The load on the press is big enough, but because too zealous with this exercise is not: raise the legs can not only up to the bar, but also to the position of 90 degrees, which is much easier.