No matter how you try sometimes one small wrong movement, can result in injury. Crossfit or no crossfit it’s inevitable if you are constantly challenging yourself.
To minimise injury ensure you include mobility practices and myofascial release in your weekly routine. I can guarantee you will get your bang for your buck in terms of improved health and performance. Check out this article from Tabata Times. “A research at Memorial University of Newfoundland showed that a mere two minutes of foam rolling led to an 8-10% increase in the range of motion”.
Below are 2 starter videos focusing on a common area, the shoulders. All you need is a lacrosse or cricket ball to get started. Remember when thinking about the shoulders it’s not literally just the shoulders. The human body is all connected. Your issue may be in the neck. I would always recommend seeing a Physio as soon as possible. Early detection and addressing the issue before it gets worst, is always the best.
For more myofascial release exercises and mobility refer to Mobility WOD.