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.
The most common cause of hip pain is osteoarthritis (OA). Other causes of hip pain include rheumatoid arthritis, osteoporosis, osteonecrosis (death of bone caused by insufficient blood supply), injury, infection, and bone tumors.our hip is one of the largest weight-bearing joints in your body. When it's working properly, it lets you walk, sit, bend, and turn without pain. To keep it moving smoothly, a complex network of bones, cartilage, muscles, ligaments, and tendons must all work in harmony.