On average among OECD countries, there are about 14 students. per teacher at the secondary level (Table D2.2). As the differences in student-teacher ratios indicate, there are fewer full-time equivalent students per full-. time equivalent teachers at the secondary level than at the primary level of education.
Causes of Lower Back Pain. Home/Conditions/Causes of Lower Back Pain. Pain in the lower back has a multitude of causes. The discs, facets, pars interarticularis, sacroiliac joints, hip joints and nerves can all cause a form of lower back pain.
Aside from kidney infection, kidney injuries can also cause kidney pain at the lower back. Accidental fall could constrict one kidney affected by the fall and damage it. Moreover, kidney stones can also cause lower back pain which sometimes spread around the back, side or front part of the body.