This ultra versatile machine allows for training of both the gluteus maximus and the hamstrings muscle group. By pivoting your body forward at the knees the hamstrings are forced to work harder. By pivoting at the hips the glutes are more involved in the lift.
As there is no curved thigh pad this machine is able to be used for the more advanced pivoting at the knees movement, which places greater loading on the hamstrings. However, if that is initially too difficult simply bend at the hips a little to utilise the glutes until you reach a comfortable height, then straighten the hips to place the load back on the hamstrings. Another technique trainers use if the loading at the horizontal position is too great is to 'push up' with your arms while horizontal, as a form of assistance to get yourself moving.