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 Anatomy: Pain Sources. General causes of hip pain include: 1  Muscle strain. 2  Bone fracture (such as a fracture of the femoral neck). 3  Tendinitis. 4  Arthritis. 5  Bone spurs or other malformations of your hip.