You can get it in the legs to, as the structures deep within begin to relax. If you take a few deep breaths and relax so the all the air escapes your lungs, you will most likely experience them. A normal part of the relaxation process.
I agree with Jim, pilates would be great. Stretching is fantastic for the body, too. When you are sensitive, it feels fantastic. You can relax into a very deep stretch without hurting yourself if you concentrate deeply and breath slowly. Once you find a good pace you can make some serious headway, as this helps to even out the ups and downs. Instead of intense meditations for a while and then meditations that seem to struggle, you hover between the two extremes.
Once you can relax and feel empty within, energy will flow through the nervous system causing different behaviors. You might look up or down, your stomach or another region spontaneously contracts. These simple movements seem strange but they lead into more purification, and when you get to that point it all starts to make sense on an intuitive level.
I've been doing the chin tuck for a couple years now and it has freed my neck and chest region. Recently I've felt this 'freeness' opening up the lower chest and solar plexus area. When the kundalini flows through this region, my stomach will flex, huff, and puff, and breath with the energy. I've read about this behavior and have simulated a few times but only recently has it become more automatic and natural. This has to do most directly with the stretches and positions I've been doing to free up the energy, but indirectly it has to do with patience.
The experience of these new sensations will always be popping up. They are good signs to see, as your inner silence flies by them. When you watch a set of dominoes fall, you don't stop at one of the fallen dominoes to miss the climax. You observe with an unmoved focus the dynamic action until the set is over and a new one begins.
