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.
Common sources of the symptom include overexertion/over-exercising, improper gait, poor posture, sedentary lifestyle, etc. What many do not realize is that much lower back pain can be traced back to the muscles of the hip; that is, when the hip flexor muscles are overly tight, they can lead to pain in the lower back. There is, indeed, a relationship, between lower back pain and tight hip flexor muscles and this will be elucidated below.