If you're looking for an exercise class that has a meditation component, you might be interested in yoga or tai chi. Both practices have their origins in eastern spiritual traditions. Both emphasize stretching and strengthening. Both focus on increasing the flexibility of the spine.
Where some forms of yoga emphasize getting into a posture and easing deeper and deeper into it, tai chi tends to work on stretching through dynamic movement. When you do a tai chi set or practice the movements of chi kung exercises, your goal is to flow constantly from one part of the move to the next, never to hold one pose.
Unlike yoga, tai chi is a martial art. Some classes emphasize the martial arts aspect of tai chi more than others. Although I train students gently and always match my lessons to the pace of the individual, I do show people how the movements would be used for self-defense. Although many people who come to my classes are hesitant about this aspect at first, they often find that it becomes their favourite part of tai chi. Most people find that it is much easier to access the warrior spirit within than they would have thought! Like any martial art, tai chi gives you a keen mental focus that is stimulating and uplifting.
Where some yoga poses require the student to use his or her arms to support the body (e.g., downward dog), tai chi does not involve the arms in this way, except in some advanced exercises that are not introduced in the beginning. If you have any concerns about putting pressure on the joints in your hands, wrists, or arms, it may be that tai chi is a better option for you.
Tai chi and yoga are two different paths to the same goal: health, joy, and inner peace. The ultimate answer to the question of which to choose has to depend on you. Ask an instructor in each of the forms if you can sit in on a class and observe. Take your time and shop around. See which one speaks to you.