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 may be caused by problems in the bones or cartilage of your hip. 1  Hip fractures can cause of sudden hip pain. 2  These injuries can be a serious and lead to major problems. 3  Hip fractures are more common as people get older because falls are more likely and your bones become weaker.