HAVING SHOULDER PAIN? READ THIS! Research shows that the lowering phase of the bench press is associated with shoulder injuries. This may be due to extensive horizontal extension of the arm, bringing the elbows below the torso (i.e. below the bench). This increases the risk of soft tissues trains/tears, anterior instability along the glenohumeral joint, osteolysis of the distal clavicle and dislocations.
Repetitive movements where the humerus is extended posteriorly (e.g when you lower your elbows below the bench) place stress on the anterior shoulder tissues, which excessively increases mobility and over time leads to anterior instability. Osteolysis of the distal clavicle occurs when the acromioclavicular joint (AC-joint) is placed under repeated microtrauma due to incorrect bench press technique (excessive arm extension). This also causes a widening of the AC-joint and increases the risk of subchondral stress fractures.
If you have long forearms, a good rule of thumb is to finish the descent phase approximately 4-6 cm above the chest. You’ll lose your full range of motion, but you reduce the risk of injury. This is basically only applicable to the recreational lifter, as competitive power lifters must lower the bar and touch the chest.
C. Barnett et al. Effects of Variations of the Bench Press Exercise on the EMG Activity of Five Shoulder Muscles. Journal of Strength and Conditioning Research. 1995; 9(4): 222-227.
G. J. Lehman. The Influence Of Grip Width And Forearm Pronation/Supination On Upper-Body Myoelectric Activity During The Flat Bench Press. Journal of Strength and Conditioning Research. 2005; 19(3): 587-591.
Morey J. Kolber et al. Shoulder injuries attributed to resistance training: a brief review. Department of Physical Therapy, Nova Southeastern University, Fort Lauderdale, Florida.
C. M. Green, P. Comfort. The Affect of Grip Width on Bench Press Performance and Risk of Injury. Strength and Conditioning Journal. 2007; 29(5): 10-14.