A Reverse Spine Angle is any excessive upper body backward bend or excessive left lateral (for right handed golfers) upper body bend during the backswing. Essentially it is when your spine/head is angled toward your target during the backswing.  This swing characteristic makes it difficult to start the downswing in the proper sequence, because the lower body is in a position that usually limits its ability to initiate the downswing. The upper body tends to dominate the swing when the lower body can’t start the downswing or has a limited ability to initiate the movement. The upper body domination will eventually create path problems and limited power output. This swing characteristic also puts excessive tension on the lower back due to forced inhibition of the abdominal musculature during the backswing and is the leading cause of low back pain in golfers. 

The easiest way to diagnose a reverse spine angle is to use the spine angle line at the top of the backswing from the face-on camera view. Advance the video to the top of the backswing. Draw a line from the middle of the head to the middle of the waist. The line is called the spine angle line. If you are looking from the bottom of the line to the top, it should point away from the target. If the spine angle line is pointing towards the target (even just a little bit), then you have a reverse spine angle. 

Several physical characteristics must be developed in order to maintain your spine angle during the backswing.

• Foremost, the ability to separate your upper body from the lower body allows the shoulders to rotate around the spine without going into backward bend or excessive left lateral bend. Limited separation is generally caused by reduced spinal mobility and shortened lat flexibility.
• Right hip internal rotation for a right-handed golfer is paramount for full rotation into the right hip without any lateral movement. If the body is unable to rotate around the hip due to joint or muscular restrictions, then a lateral sway may occur. Any lateral sway during the backswing will force the spine to tilt into backward bend and create the reverse spine angle.
•  Finally, the ability to stabilize the spine angle during the backswing is directly proportional to the strength and stability of the core musculature (your abs and glutes). The core is king when it comes to spinal stabilization. These muscles help keep the thorax forward flexed throughout the golf swing.

Reverse Spine Angle swing characteristic can also be caused by:

• Too much pelvic tilt at address which can cause an “S” curvature in the lower spine. If this does not return to neutral during the backswing, it can cause the Reverse Spine Angle characteristic.
• Lack of forearm rotation on the backswing can cause the golfer to lift the club into position on the backswing
• Improper pelvic side-bend at address. If the trail side hip is too high at set up, it can create the Reverse Spine Angle during the backswing.
• The player trying to keep their head still during the swing.