Hello, Thanks for your query. Lower back pain is not related to masturbation.The low back ache is a result of muscle spasm which in itself is a protective mechanism body develops so that the back avoids abnormal posture. For pain to go, it takes not only rest (on a comfortable bed) but also avoidance of particular positions (during work, rest or recreation). Avoid sleeping on sides and stomach in case you do. While on work don t sit in one position for more than an hour and take frequent stretch breaks. Do not bend forward to lift things up, bend the knees and hips for that. Also discontinue any strenuous activity or exercises for some time. I do hope that you have found something helpful and I will be glad to answer any further query. Take care