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.
Back pain is more common in people who are not fit. Being overweight. A diet high in calories and fat can make you gain weight. Too much weight can stress the back and cause pain. Heredity. Genes play a role in some causes of back pain, such as certain types of arthritis. Other diseases. Some types of arthritis and cancer can cause back pain. Your job. If you have to lift, push, or pull while twisting your spine, you may get back pain. If you work at a desk all day and do not sit up straight, you may also get back pain. Smoking.