Phaetrik Murphy as the u.s. trainer training Triceps Dips Pier says on the bench to make the shoulders is a risk of injury to the rear to loosen it. As a result, elbow must exert hard, which is why there is a pain.
Patrick Murphy, the renowned US trainers say the practice Triceps Dips on the bench in a position to make the shoulder more vulnerable to injury. With a hand behind it. The elbow must exert hard. Which causes the pain.