Does pressing on muscle knots make them go away?

It depends on how you press on it. A muscle 'knot' is usually referred to as a trigger point. If it is a trigger point, rather than a tender point, when you press on it, it will 'trigger' pain in an associated area. If it is a true trigger point, it will have a condition known as ischemia, which means it is lacking normal blood flow, and that is what is causing the pain. The best way to check is to gently rub across the muscle tissue to find the taut band, a then follow the taut band until you locate the trigger point. The amount of pressure that you should apply, or better yet, a professional massage therapist trained in neuromuscular therapy, is about a 7 or 8 on a scale of 10, where 0 is no pain, 5 is medium pain, and 10 is unbearable pain, the kind that makes you resist, or tighten up. This is called guarding. If you get to the 'sweet spot' there will be some pain, but it will feel like good pain. Another important component is breathing, while the pressure is being applied, you should be able to do relaxed abdominal breathing. If you let out a sigh of relief, then that is the signal that the pressure was just right and it is time to gently release the pressure off the trigger point.