Some experts even believe that most movement comes from the core. On a regular basis I see people who have injured one or a few of their core muscles and have a lot of trouble moving.
Your core muscles consist of all the muscles from the bottom of your rib cage to the tops of your knees, on the front and back of your body.
These muscles control getting up, sitting down, any movement of the legs or torso. These muscles stabilize your torso when you are moving your upper body and your lower extremities.
If you strengthen up your core, you will stabilize your mid back, lower back, hips, legs and even to your necks. If you want to grow old gracefully, with little pain or discomfort, then it is essential to strengthen up your core muscles.
Here is a slide show with some good core strengthening exercises.