Caterpillar Yin Yoga pose
Mechanic - Decompresses the spine, targets the Hamstrings and Thoraco Lumbar Fascia (Erector Spinae).
Energetic - Replenishes energy, targets the Urinary Bladder Channel relating to the Water Element.
Mind/Emotion - Enhances introspection, Calming, soothing.
Be mindful in case of herniated disc or sciatica, this pose might aggravate the condition.
Help & Props
If suffering from an injury or very tight Back/Hamstring, you might try the following : Using the wall will greatly reduce the stress on the back while keeping a fair stimulation on the hamstring, Laying on the floor with the hips very close to the wall, legs together supported by the wall.
Another alternative is to roll a blanket under the knees, and/or to seat on a pillow to play with the height of the seat until you find the right position which allow you to create a slope, this will change the tilting of the pelvis and reduce the stress on the legs.
Releasing the pose
Gently retreat your hand back and come to a seating position with your spine up, then lay back in Savasana or Pentacle.
Minimum time to hold the pose is 2 minutes to affect the connective Tissues, typically the pose is held around 5 minutes. The caterpillar is one of the pose in the Yin repertoire which can be held longer up to 10 minutes or more (for experienced practitioner), or several rounds of 5 minutes.
Rounding the spine is a must try, do not worry about the position of your feet or the angle of the legs so much, props are good until we do not need them anymore.