Grip 1 (pictured above left), with the fingers interlaced and the pointer finger extended, is the most beginning of the grips. By linking the hands together we can engage the arm muscles to straighten the arms and stretch and strengthen the shoulders.
Grip 2 (pictured above center), with the palms together and only the thumbs crossed, is more challenging than Grip 1. Each arm straightens with mostly its own strength, so our shoulders, chest, back and arms need to be more flexible and strong. The crossed thumbs allow for a little bit of bracing and support from the opposite arm.
Grip 3 (pictured above right), with the palms flat together, is the most challenging and advanced of the grips. Each arm is completely independent, so the shoulders and arms become symmetrical, not relying on the stronger arm to carry the weaker one.
HOW TO CHOOSE YOUR GRIP
Simply put, choose the most advanced grip you can while maintaining the integrity of whichever posture you are practicing. This requires some body awareness. If, while in the posture, you feel your arms or upper body start to collapse or become uneven, change your grip to a more stable version. As you transition to more advanced grips, draw your attention and focus away from the hands and into the shoulders and torso, building symmetry and awareness of the center of the body.
An excerpt from the Ghosh Yoga Practice Manual – Intermediate



