Guys, thank you so much for the tagging and I am really sorry I've taken so long to respond, it's been that kind of week already. Both illustrations demonstrate the same movement that isolates the triceps using a dumbbell, but, there is a change in grip which means that there are two changes in the joint angle taking place, first at the wrist and then at the shoulder. This change in joint angle also changes the load that the joints experience which means it changes the load experienced by the tendons, ligaments and satellite muscles. This very specific strengthening of the joints that occurs as a result is then expressed in increased strength by the shoulder joint as a whole. I hope this helps to explain it a little better but please...