Are dips on a bench (with feet on the ground) dangerous for the shoulders? And which grip is safer; internally rotated on the front of the bench or in a more neutral position with the hands on the sides of the bench? Can you also explain why?
First of all, the question(s) I have for you is: WHAT IS YOUR GOAL? WHY HAS THIS EXERCISE BEEN SELECTED? WHAT PHASE OF PROGRESSION HAVE YOU DEEMED A DIP TO BE NECESSARY?
Second, a dip requires a great amount of active ROM at the shoulder girdle. An individual must have the ability to actively extend the shoulder to 45 degrees without compensation to perform a full dip. If the individual does not have this ROM (which most will not due to our automated and seated society which has caused an abundance of "UPPER CROSSED" postural distortion, characterized by rounded shoulders and a forward head), than the exercise may cause unnecessary wear and tear to the tissues surrounding the joint. If an individual insists on performing dips, you might instruct her/him to draw the knees up (flex at the hip and knee), so as to shift the center of gravity toward the anterior, there by reducing stress, via requiring less ROM of extension at the shoulder to perform the exercise. A traditional dip is primarily a SAGITTAL plane exercise, moving outside of this plane (internal rotation), will decrease available ROM, and may further increase stress at the joint.
The moral of the story here, is that there are safer exercises available out there. We must always have a scientific rationale and system of progression for our exercise selection. Isolated, uniplanar, traditional exercises MAY make up only a small part of a well balanced periodization plan. Developing more advanced skills as a fitness/performance professional may take some "up-education" on the basic sciences of FUNCTIONAL ANATOMY and MECHANICS as they apply practically to exercise.
- ESSENTIALS OF INTEGRATED TRAINING SERIES by Mike Clark and Alan Russell
- INTEGRATED ANATOMY FOR THE NEW MILLENNIUM by Lenny Parracino