We all love pictures...so here are a few examples of the t-spine in action. Obviously, t-spine mobility is critical for sparing other structures during high velocity rotational movements like throwing and swinging. However, I added the last picture (because it was awesome) as a reminder that dynamic stability of the t-spine is critical for movements such as sprinting and long distance running. There's a fair amount of rotation that occurs during these movements as well and for the core to remain stable (eeek how sick are you of hearing that?) and elastic, the t-spine must be able to move. The t-spine is also a base to which the ribs attach and inside the ribcage are some pretty important items that need room to work.
My friend Carson Boddicker (www.boddickerperformance.com
) has written some fantastic articles on training endurance athletes, one of which he dissects, in serious detail, training the ribcage for function - check it out.