Okay I was 16 and hadn’t done it in a few weeks so went at it super hard. 10 minutes in my thigh is hit with the worst cramp I have ever felt. I was kind slumped over and immediately sprang up and laid flat on my bed. I got up to “use the bathroom” and noticed my back felt like it just got hit into by a car. I couldn’t stand up straight and could barely walk. After the ordeal I went back to bed, when I woke up my back had the exact same pain. I missed school that day and told my dad I probably just fell off the bed. I went to the chiropractor and found the my cramped up thigh dislocated something in my hip/lower back area and one of my legs was now longer than the other. I became so paranoid of further masturbating that I didn’t do it for a whole month.
Source: reddit.com/r/gonewildstories/comments/c27twc/i_once_masturbated_so_hard_i_hurt_my_back_and_had