Your trunk or torso is the combination of your back, abdomen, chest and pelvis.
This great big, composite structure does many things, including the very obvious joining of your upper and lower body together. In joining the upper and lower body together it plays a very important part in transmitting forces between the arms, the legs and the ground so it’s important in pretty much every single thing you do!
The many muscles, bones, and other connective tissues of your trunk need to be strong, mobile and work together in a coordinated fashion to produce efficient movement. The strength, mobility and coordination of your trunk are one of the biggest risk factors for musculoskeletal injury and one of the biggest predictors of successful injury recovery.
In most instances your ‘core’ is really thought of and trained as thought it is just the abdominal structures. This is a pretty narrow view of things… ‘The core’ is really part of the trunk but it is not all of the trunk so strength and rehab strategies that only focus on the abdomen are almost always doomed to fail.
You must ensure all elements of your trunk or core are strong & mobile, because you’re only as strong as your weakest link.
This global emphasis on the trunk, including the mid and upper back and chest is one of the key things that set clinical rehabilitation strategies and gym/fitness services apart.