Are the "!!!" Supposed to be because its heavy?? Cuz it certainly isn't, especially for Ronnie.
..and that "jerking/catching" movement (where the eccentric part of the movement is suddenly halted and 'snapped' back initiating the concentric) is likely part of what contributed to Ronnie back being as bad as it is. You'd think he'd have somebody point that out to him, as if he didn't already know.. Yet he refuses to make changes.