Hi, You haven t mentioned how many times a week. But generally, few times a week doesn t qualify for the term over-masturbation . In fact, the process should reduce your pain as it releases soothing hormones inside your body. You need to look our for other things that are most probably contributing to your back ache. I would suggest you to look out for your sleep posture and sleeping bed as bad posture or bed can be contributing to your backache. Consult an orthopedic for your backache. You might be offered physiotherapy or medications or both. I hope the above information solves your query. Thanks for writing into healthcaremagic.