A dedicated yogi friend recently asked me why it is much harder to get into a traditional Eka Pada Rajakapotasana (Single Leg King Pigeon) than into Mermaid Pose? Let's take a quick look at the anatomy to compare!
These variations focus on opening differing areas of the shoulders and depths of backbending. The traditional variation really focuses on a deep flexion and good external rotation of both shoulders (reaching over your head and rolling your triceps to face forward). This involves a big stretch of the teres major, latissimus dorsi, and pectoral muscles which can often be very tight on people for many reasons. A traditional Eka Pada Rajakapotasana also requires some good thoracic extension (upper back bending) to both put the shoulders and shoulder blades in a good position to lift and to let you reach back far enough to reach your feet.
Poses such as lying on a yoga block, Anahatasana (Puppy Pose), Dolphin, and pushing to down dog can help you gain the needed mobility.
Mermaid pose is easier to get into for most yogis because the shoulder of the binding arm needs mostly horizontal abduction and some extension (pulling your arm back) which are easier motions for most. This involves opening up the anterior deltoids and pectoralis major muscles. The top arm does a similar action as in the traditional variation, but it needs much less external rotation so less stretch of those tight latissimus dorsi, teres major and pectoral muscles. Also, the back bend in the upper spine doesn't need to be as deep in Mermaid.
Mermaid pose is easier to get into for most yogis because the shoulder of the binding arm needs mostly horizontal abduction and some extension (pulling your arm back) which are easier motions for most. This involves opening up the anterior deltoids and pectoralis major muscles. The top arm does a similar action as in the traditional variation, but it needs much less external rotation so less stretch of those tight latissimus dorsi, teres major and pectoral muscles. Also, the back bend in the upper spine doesn't need to be as deep in Mermaid.
Ustrasana (Camel Pose), Ardha Bhekasana (Half Frog Pose), Salabhasana (Locust Pose) on top of the above poses can help prepare your shoulders for Mermaid.
Hope that helps!!!
Namasté
Hope that helps!!!
Namasté
Yoga pose pictures from yogajournal.com.
Anatomy images from Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System.
Anatomy images from Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System.