Uncomfortably Weird Feeling 6 Years After Saline Implants

I have heard this complaint from people in your situation. Over time, saline implants, especially those under the muscle, may get very loose. The pockets they are in becomes very big and they can move around a lot. Capsular contracture is also possible but it sounds more like yours have become loose. When you change position or your muscles contract, the implant may shift, causing a weird feeling. It isn't dangerous but if it is too bothersome you want a revision. Contact your doctor for an evaluation

This feeling may be caused by a number of things (scarring, rupture, leakage, etc.) One of the more common things would be scarring or "capsular contracture." This can be treated by removing the scar tissue and either replacing the implants or using the same ones. However, you should be examined in person to determine what may be causing your feelings. I hope this helps!