The transverse abdominis muscle: your natural girdle
The transverse abdominis, like the rectus abdominis muscle leans toward mythical properties. Many people have associated weakness in this muscle with lower back pain. That is debatable, but what isn’t debatable is how interesting this muscle truly is.
What does the name transverse abdominis muscle mean?
Transverse means across. Abdominis comes from the Latin word abdere which means to stow away. From this then you get an idea that the abdominals, in general, function to “stow away” contents (the digestive organs).
Where does the transverse abdominis muscle attach?
The transverse abdominis is not really considered to have a typical origin or insertion because the muscle fibers run horizontally.
It attaches at one end (considered the “origin” by some) at the inguinal ligament, the iliac crest, the thoracolumbar aponeurosis and the internal surface of the costal cartilages 7-12.
It attaches at the other end (considered the “insertion” by some) on the abdominal aponeurosis and the linea alba.
What actions does the transverse abdominis muscle do?
The function of the transverse abdominis is to compress the abdominal contents. It’s the natural girdle we all wear. As is the case with all of the abdominal muscles, stabilization is a key function.
Poses where this muscle contracts
If we look at a posture such as navasana we see that all of the abdominals will be doing an isometric contraction in order to help stabilize the trunk.
A posture such as parighasana requires lateral flexion of the spine. So as we lean over our left leg, the left side is contracting.
Poses where this muscle is lengthened
In a posture such as urdhva dhanurasana we can see lengthening of all of the abdominal muscles as the rib cage and the pelvis move further apart.
In a posture such as parighasana, as we lean over our left leg, the right side of the body is lengthening.