Ronnie had freakier biceps, Sergio had fuller lateral and long head of the triceps. But, he was injured in one of them (correct?) hence the one looking kinda shortened.
Tore his left triceps in an accident.
Also had quite bad arthritis in his elbows and knees, which apparently reduced range of motion and why he used half reps for bench. Squatting also became more difficult and that's one reason why his legs were smaller in the 80's. He later had to have several joint replacements.
He liked test and winstrol, which probably contributed to this as they would dry out his joints.
