For the understanding of the atypical sciatica you have to know that pain- or other symptoms below the waist line nearly regularly are the result of a mixture of pain of either the spinal nerves or of the meridians. I just estimate that below the waist line the proportion between spinal nerves- and meridian pain is about 50% to 50%. This relation changes in the upper body parts to the advantage of the meridian pain, as upwards the compressive load decreases and the spinal nerves are not so easily affected.
However this means that for the treatment of a calcaneal spur or a repeatedly occurring podagra (gout) not only the release of the sciatic nerve is necessary by means of the elimination of subluxations of the leg joints and a pelvic damage in the sense of the SMT®, but also the release of the nerves of those vertebrae, whose meridian runs through the sickened area.
Please also pay attention to those vertebrae and organs being connected to and over the functional circuits, which again are connected among each other.