Breath in while visualizing energy going up the spine to the back of the head. Hold in a moment. Breath out visualizing the energy continuing the circle to the front of the body downwards back to the bottom of the spine. Hold out a moment. Repeat 24 times.
If there is a daily practice, 12 repetitions can be added to the mix every month.
Quality of Intent is everything in this practice.
If any pain or discomfort is felt stop and fix the physical or energetic imbalance before continuing.
Balance and honesty devoid of ambition is the way to not get hurt.
For more info about Kriyayoga see:
This seemingly simple and innocent practice can be a life line and savior for spiritual people living in stagnant routines, a wild flyer and physical and energetical weakness.
At the very least it gives a level of physical wellbeing.
At any rate, balance is a necessity so ocasionally one should give it up for some time and work in silent awareness without any action involved, in order to avoid being entangled in it as a routinary affair.