Bending backwards, literally.
Backbends in yoga are a great way to stimulate the nervous system and energise the whole body, but many people struggle with deeper backbends such as urdhva dhanurasana (wheel pose) and urdhva mukha svanasana (upward facing dog).
It is a myth that in order to be able to do deep backbends you need super strong arms. In reality you just need enough flexibility in the shoulder joints and hips to be able to support such positions. As always, the right alignment is essential to get you into a safe pose.
In wheel pose, a deep hip extension helps to lift the body, moving the action away from the glutes and quadriceps alone, and distributes the weight over the legs, which as a result puts less stress on the upper body and lower back area.
The upper arms need to externally rotate to create more space for the shoulder blades at the back as they slightly separate, and at the same time the rotator cuffs (the muscles that keep the head of your upper-arm bone, the humerus, in your shoulder socket) have to stabilise.
We encounter similar actions in upward facing dog, where the legs play a vital role to protect the lower back area and maximise the extension of the hips.
Understanding the actions that the joints and muscles play in yoga poses is essential for a safe and enjoyable practice. I also find the process of discovery and observation very insightful and something that should be encouraged. In the end it doesn’t really matter if you can’t fully do a pose, but that process of discovery to me is really priceless.