Ki means a few different things - literally 'breath', but the metaphorical (and intended) meaning is more like 'the light bubbling motion throughout a well co-ordinated body'. Don't fall in love with it, or get addicted to it. Appreciate it and it will follow your intention and facilitate your movement (and stillness).
This is more easily identified when the Ki is stuck or broken - and the corresponding movement and anatomy are rigid, or limp, or jerky.
Martially, Ki movement is behind every physical movement. Intentional movement of Ki will drive physical movement with more speed and clarity. With longer training, Ki provides protection against strikes - "Iron Shirt" conditioning. In this case, the attack and the attackee are joined at impact, and directed Ki integrates the force of impact with the whole body (rather than the local point of impact). Breath control, guidance of Ki, absense of tension, strong 'presence', and daily practice are paramount. Daily practice is not as great as burden as it might seem - every daily action can be Ki moderated and is an instance of training. The action is more functional, 'easier', and more fun. [I include 'catching a fly below' as an example].
Practice in a safe place.
Stand, feet shoulder width apart. Knees over the toes (front of knee is over front of toes). Elbows are just out from the side of the body, and slightly bent.
Still the rational mind and attend to the dan jun - try to wiggle in slow motion originating from the waist region. Now slow the wiggling and limit its extent. When the body is still, the rest is Ki.
Breathe slowly and regularly, where the belly does the breathing. Panic not, and control your temper - now the Ki can settle.
'Wiggle' (imperceptibly) up the spine on the in-breath - to the top of the head. 'Experience descending light rain' down the front of the body on the out-breath. Stay relaxed - no strain. Relax the neck. The shoulders, hips and ankles are in a vertical line (most people lean back). No tension - wash the tension out.
Take two Aspirin and call me in the morning. [Ie, lighten up - this line is a joke].
Still the rational mind. Half close the eyes. Take 15 to 20 minutes.
Slowly come back to calm alertness of your surroundings.
Rest.
Horse stance. Chest open. Outer wrists at floating ribs (elbows back) ie, palm up.
IN Breath, then...
Hold breath for six.
Turn over hands and face palm 45 degrees to front (where you might start to knead a large piece of dough). Take (outward) tension into the torso and arms (front of body is relaxed) and Breathe OUT (Hiss) (to the count of six), as you extend the arms forward till nearly straight. This starts with a determined suddenness.
Relax!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
To a six count, breathe IN, separate arms and retract them to "Outer wrists at floating ribs".
Hold for six.
This is one cycle.
[You can take the six up to twenty seconds. At least three cycles].
Same as above, but skip the "Hold for six". Hold on the press out, and then 'Ha!' it out at the end. The 'hold' involves no compression of the lungs or lower belly - but the muscles of the abdomen and back are holding some tension (as they 'guide themselves' outwards.
Of course, this is a form of cross-species sparring! :-)
Tom Osborn - probably 1998. I should revise this page. When you get older, there are more subtle things to do.