Backache and Sex
Sex has nothing to do with backache directly. Over indulgence in the sex or even masturbation does not lead to backache. The feeling of exhaustion, tiredness, lassitude, listlessness and other similar expressions used to describe the 'post sex' or 'after night' effects are psychological in nature. It has been observed that these sort of symptoms are encountered more often in adolescents who have a very 'strict and holy' atmosphere at home and elders with 'puritan approach' to life. This induces a guilt complex in their minds and arouses greater curiosity to know and participate in sexual activities. Similarly, the adults who have extramarital sex relation develop an idea of guilt and have a 'pricking conscience' all the times because it is an act which neither their spouse nor the society approves. Backache is sometimes picked up, at the subconscious level, as a symptom by these people as self-inflicted punishment for their misdeeds and immoral acts that they had indulged in.
Besides this there are certain causes of backache which are related to reproductive system in females. They are not directly linked with sex though reproduction is the natural sequel of sexual activity.