Intermittent claudication is a condition in which what happens when walking or can be just sitting around?

Usually walking. Claudication means leg pain with walking. Spinal (neurogenic) claudication comes from narrowing (stenosis) in the low back spaces for the nerves to and from the legs. The same pain, numbness, tingling, weakness, heaviness that occurs with walking will comes happen with standing. Sitting flexes the spine, making nerve channels larger, so the person usually feels better sitting.