Backbends, what a story! 2d episode: biomechanics

Now that you know all (or nearly all) about the anatomy of the back and before giving you precise tips to practice backbends safely, lets speak a bit about the biomechanics of the postures in general.

In every asana, 5 elements work together:

  • The position of joints
  • The muscles that contract (agonist muscles)
  • The muscles that stretch (antagonist muscles)
  • The breath
  • The bandhas (that can be define as contractions and that give stability to the postures)

Position of the joints

A posture depends firstly on the position of the joints. What gives to the joints its angle is the synergy of the engaged muscles. As so it is important to know which are the main muscles that are used in a specific asana and for what reason.

The agonist muscles reduce the angle of the joint while the antagonist muscles work like a mirror: they extend and open the joint.

For example, to bend the knee the hamstrings (behind the thigh) contract while the quads (front of the thigh) extend.

Muscles to contract and to extend

In a backbend 3 parts of the body have to open :

  • The shoulders
  • The rib cage
  • The hips

Opening of the shoulders

To open the shoulders the main muscles to contract are the posterior deltoids, the rhomboids and the trapezius. By reflex the anterior deltoids and the upper pectoral muscles will extend.

Opening of the chest

To open the rib cage, the muscles located along the spine (the erector spinae) and the quadratus lumborum have to contract. That will allow the muscles of the front body (especially the rectus abdomen muscle and the pectoralis minor) to stretch.

Opening of the hips

Backbends need an external rotation of the hips. The prime mover for this external rotation is the gluteus maximus followed by the hamstrings. While they contract the muscles in the front of the hips extend, especially the psoas - main hips flexor -, the rectus femoris and the adductors.

The breath

The breath matters a lot in backbends to support and deepen the postures.

As a matter of fact, each inhalation refill the lungs with fresh air. It helps opening the rib cage and stretching the muscles of the front body.

With each exhalation, the front body will stretch even more to create maximum space in the back body to avoid compression in the spine, especially in the fragile area of the lumbars.

The bandhas

Among other things, the bandhas are used to stabilize the joints.

With backbends the most used bandha is the contraction of the perineum (mula bandha).

It helps extending the lower back, tilting naturally the tailbone forward. This extension, assisted by the contraction of the abdominals, protects the lumbars.


As you can see, practicing a backbend requires a synergy of several techniques and it can seem quite complicated but with the precious tips that you will discover in our next and last episode of this series you will certainly feel more comfortable with backbends and become a big fan of them!