L base

From Acrobalance

The base is lying on his or her back with the feet in the air. In this position the base may support weight on the feet and/or hands. This position is also known as Risley, so named after the circus performer Richard Risley. It is also a very common position in acro-yoga.

Notes

Though the arms and legs may bend for mounts or transitions, the strongest position is with the legs or arms straight, vertical, and with the hips and shoulders somewhat relaxed so as to press against the ground. This allows the weight to go straight down the bones into the ground.

There is a tendency in beginners to move the feet above the chest, which uses more muscle and is ultimately less stable. This is partially due to inflexibility in the hamstrings. To alleviate some of the stress on the hamstrings, a small mat may be placed under the hips/low back. An extreme form of this support is seen in Icarian Games (aka foot juggling).