BODY DECOMPRESSION
One of the assumptions of the physical practice of Yoga is that the body needs to decompress. Decompression is achieved by practicing postures (asanas) which consist of gently pulling body parts in opposing directions.
LINES OF ACTIONS (VECTORS)
In a posture a Line of Action is an intention characterised by a direction and a magnitude. A line of action does not necessarily generates movement.
Establishing Lines of Actions (vectors) in your yoga practice will help to decompress your joints and lengthen your body.
Here’s an example for Chair pose (Utkatasana):
– Stand tall at the front of your mat and align your feet;
– Instead of initiating the posture by bending the knees establish these two lines of action.
FIRST LINE:
– Bring your mind to your sit bones (ischial tuberosities);
– From the sit bones REACH BACKWARDS and DOWN while keeping your chest open and forward facing;
This action will make your knees bend slightly without losing structural support from your lumbar spine, don’t go too low and don’t let your knees go too much forward.
SECOND LINE:
– REACH UP and FORWARD with your arms and shoulders, in the opposite direction of your sit bones;
– Imagine that you are reaching for something or someone.
Avoid tilting the head upward, it will most likely compress the back of your neck. Instead keep your neck aligned with the rest of your spine;
Keep feet and toes grounded.

If the posture is steady and comfortable and you wish to challenge yourself explore reaching further back with the sit bones as long as the posture remains steady and comfortable.
For Chair Pose we use the sit bones and arms for establishing the Lines of Action. One can use Lines of Actions in all yoga postures, the only differences will be the anatomical landmarks and directions.
Enjoy!