The shoulder is one of the more complicated joints in the human body, so it usually benefits from a good warm-up. As tempting as it may be to grip it and rip it when faced with a WOD, spending a bit of time loosening up your joints is a great idea and will improve performance and reduce the chance of injury.
Working with a group of athletes at CrossFit Santa Cruz, Kelly Starrett goes through a thorough warm-up designed to get the shoulders ready for high-intensity activity. Starrett starts the athletes in the push-up position, which also helps warm up the core.
As the shoulders loosen up, Starrett has the athletes go through a larger range of motion, eventually bringing them over to the pull-up bar for some body-weight work. From there, the group is ready to hit a WOD.
Starrett is the owner of San Francisco CrossFit and a doctor of physical therapy.
Additional reading: CrossFit Shoulder Therapy by Tyler Hass, published Oct. 1, 2005.