Shoulder and Upper Back Positioning
Pointing the thumbs backward allows the shoulders to come slightly forward, creating more upper-back flexion. The thumb-backward hand position allows the shoulder blades to sit smoothly against the upper portion of the ribcage.
1 sources - 2 claims
Pointing the thumbs backward allows the shoulders to come slightly forward, creating more upper-back flexion. The thumb-backward hand position allows the shoulder blades to sit smoothly against the upper portion of the ribcage.