It is common that a client will come into my massage clinic complaining of an achy low back. Typically they have not been doing any heavy lifting or experienced any trauma, but it hurts and can even keep them up at night. I would perform an assessment to rule out possible disc herniation, facet joint issues or other vertebral dysfunctions. The pain description of dull and achy leads me to think it might be muscular in origin, basically it could be from sitting for too many hours. Knots in a muscle, aka trigger points, are irritable spots that can elicit pain when direct pressure is applied and sometimes cause a twitch response. Trigger points are fascinating in that they follow a distinct pain referral patterns for each specific muscle. For example, the diagram below outlines the trigger points in the gluteus medius muscle and the corresponding red pain pattern. I find this gluteus medius pattern often and massage can be very effective at releasing the painful points. My client will comment how they feel their low back ache dissipate after I use massage techniques on their glutes/hips, everything is connected! At home you can help minimize the pain by avoiding aggravating factors such as poor posture, dehydration, cold drafts, and not enough stretching or physical activity.