Background from Kinetic Blast: "She must have at least one hand free to aim the blast (or one prehensile appendage, if she doesn't have hands)."
Background from Pinned Condition: "A pinned creature is tightly bound and can take few actions. A pinned creature cannot move and is denied its Dexterity bonus. A pinned creature is limited in the actions that it can take. [...] A pinned creature can take verbal and mental actions, but cannot cast any spells that require a somatic or material component. A pinned character who attempts to cast a spell or use a spell-like ability must make a concentration check (DC 10 + grappler's CMB + spell level) or lose the spell. "
Casting Spells while Pinned: "The only spells which can be cast while grappling or pinned are those without somatic components and whose material components (if any) you have in hand. Even so, you must make a concentration check (DC 10 + the grappler's CMB + the level of the spell you're casting) or lose the spell."
The clarification under casting spells while pinned seems to point out an obvious but necessary mechanic for casting with materials if they are in hand, thus pinned doesn't prevent your hands from being involved, it just prevents you from moving your hands.
The description of Kinetic Blast says that the free hand or appendage is used to "aim" the blast, not that it is used for gathering and focusing the elements in the palm of your hand which would be more akin to Goku from Dragon Ball Z. (Please note that I have never watched the Airbender series and have no intention to do so, so references to that won't be very helpful to me)
So let's say you are being swallowed whole by a very large python and you are an aerokineticist that uses electric blast (or really any blast but this is the example I'm using). If the python is basically constricting on you and completely surrounding you, if you are willing to take the damage as well, why can't you just release the power straight out of your hand in whatever direction it is pointed which would include you and the snake as long as you make the concentration check? This is a mechanic as intended type of question, much in the way the casting spells while pinned clarification was.
