The Transvers Abdominis (TVA) is the deepest and in my opinion the most important abdominal muscle. It literally forms a “corset” of support around the spine and internal organs. The TVA attaches to the inside of the lower 6 ribs to the top of the pelvis at the iliac crest and ASIS (or hip points). It wraps around the waist from the thoracolumbar fascia in the back of the body to the linea alba (or midline) in the front of the body forming a “support belt” around the soft belly. The TVA has fibers that interdigitate with the diaphragm (our main breathing muscle) and some of the fibers also blend with the fascia of the psoas. It is an extremely important muscle to strengthen for low back pain, diastasis (or separation of the linea alba, which can happen during pregnancy), and abdominal hernias. A healthy TVA is supposed to contract whenever we move, raise our arms, walk, lift our leg, twist our spine, etc. but several factors inhibit its function including a sedentary lifestyle and certain poor dietary habits. It is a respiratory aid that fires when we cough, sneeze, laugh, or forcefully exhale. One of the main reasons it is so important to low back health is that when contracted it decompresses the lumbar spine and acts as a spinal support by “stiffening” the intervertebral discs to sustain loading. The Transverse abdominis plays a key role in Uddiyana Bandha, or the “flying up lock”. The usual cue for Uddiyana Bandha is to draw the navel in and up but I would further that by saying draw the entire waist in and up. Try it: Engage your TVA by pulling the sides of the waist in towards your spine and away from your shirt. Put this idea in all your asanas, and your back will be protected.