C-Posture is used to describe a posture that occurs when your shoulders are slumped forward at address and you have a definitive roundedness to your thoracic spine.
Physical Parameters Causing C Posture and How to Diagnose Them:
The C-posture is described as an excessive roundness in your upper back and can be caused by the following:
Limited thoracic spine extension.
Upper Crossed Syndrome - muscle imbalances including tight pecs, lats, upper traps, and levator scap and weakness in the mid-scapular muscles, serratus anterior, lower traps, and deep neck flexors.
Instability in the core muscles causing poor posture and the slouched forward position at address.
Lack of proper instruction - not understanding the correct setup and posture.
Lack of pelvic tilt causing the upper body to bend to address the ball.
Clubs that are too short.
Grip that is too much in the fingers of both hands