Sorry, this is impossible to understand -- knocking bones? Have no idea what that means. Have no idea what taking milk means or why it's important. Why would you think masturbation has anything at all to do with your weight? If you want to gain weight, eat more. If you want to gain muscle, do resistance training, such as lifting weights. I realize English may not be your first language, but if you can be a lot more clear about what you're talking about, you might get more help here.
Sorry for this. I meant that my joints like shoulders, wrists and knees grind against each other and also produce loud sounds knocking sound when i move arms or bend legs. I googled it. Apparently bubbles in joints pop and thus produce this sound. my question is that why this happens? Has masturbation made my bones and muscles weak? It worries me a lot
Just exircise and have a life
Well, it's definitely not because of masturbation unless you managed to get a repetitive stress injury, but those are usually painful. Milk won't help this because the issue isn't the bones, it's the cartilage in between the bones that's worn down over time. Sometimes it's a natural part of aging, sometimes it's an early sign of arthritis.