Push-ups and shoulder injury
Last week I tried a lot of push-ups. I could not do a high-rep push up so I tried many small sets like 20,20,15,15,10,10,7,5,5,3,3,2 until I could not do at all. Right after that, I felt great. One day later my triceps were sore. The next day I could fell my front deltoids burned but the third day my right shoulder got hurt a lot that I thought I had some rotator cuff problem. It was a stiff pain when I raised my right arm. Moving the arm like swimming was impossible.
I had always thought that if some exercise can make injuries then it would happen when I am doing it and hence I can stop the exercise. In this case, it appeared three days later. So how can I know if an exercise is being done properly or not to prevent injuries ? My shoulder is almost normal now and I really do not want to make it hurt again.