I am a Physical Therapist. I have seen a lot of labrum tears from behind the neck presses. I see dumbell military presses as the most complete exercise for the shoulders with a smaller risk of injury. To do standing presses seems like it takes the focus off the delts and more on the core. Also standing puts a incredible amount of compression force through the lumbar spine. With seated behind the neck presses, one has to remove the bar from the rack to get into position and this opens up for injury. Using the smith machine reduces the risk but i have always felt the smith machine was kind of worthless for many exercises. takes away the balancing aspect of the free weights. Dorian Yates called behind the neck presses worthless.