Contraction of pelvic muscle can be seen in some women. This is also another side effect of masturbation if done in excess. Pain and cramps are regular visitors if you cannot control masturbation. Generally speaking, female masturbation does not cause back pain. However, back pain can be a side effect of intense sexual activity, so listening to your body and paying attention to any warning signs is important. Additionally, if you find yourself experiencing persistent or severe back pain, it is best to consult your doctor.