Jumping Jack Wedge
Using a space between two walls, jump up and lock feet and arms outwards, wedging yourself in a splayed position. Then climb up the space by jumping and locking in short bursts until you can’t go any higher.
1
Stand in a corridor approximately one metre wide.

2
Spread arms wide and place hands on opposite walls at shoulder height.

3
Using arms for the initial push, jump upwards, locking feet outwards against walls so as to sustain an elevated position.

4
Repeat step three, jumping a bit higher up the wall each time.

5
Repeat step four until head touches ceiling.

Notes
The greater the ceiling height, the more dramatic the aesthetic.