Yes I agree, he was probably 5'8'' in his prime but after years of steroid abuse and heavy lifting and age he lost some height. I believe all pro bodybuilders lose on average about 2'' by the time they retire
^^
My Chiropractor who I have known (and worked out) with says it is from doing BARBELL Squats compressing the spine, over time it gets WORSE. He advised me early on to do
only hack squats, front squats, etc... However I am guilty of many years in the Army of doing Barbell Squats as that's what the weightlifter did in the late 80's early 90's!