The Handstand Pushup is probably one of the more complicated gymnastics movements performed in CrossFit.  It requires an enormous amount of core stability, shoulder strength, stamina, and coordination.  The standard for HSPU’s is using a wall to rest the feet on, however, achieving a free HSPU is a quite a feet.  There are little, if any beginners to CrossFit who can simply come in and perform HSPU’s.  For those that can, they usually have a strong background in gymnastics.  For the rest of the normal human beings, progressions leading up to full inversion and full range of motion requires time, patience, and practice.  Here are some progressions I recommend following to work on.