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.
Hip pain can also be the result of disease or injury to the components of the hip or surrounding nerves. Additionally, hip pain can sometimes be caused by diseases and conditions in other areas of the body, such as the lower back or knees. This type of pain is called referred pain.