That's the fellow! The article seems ok but - I'm not a physio btw, just a climber - it advises holding a weight palm-up for the eccentric exercise.
Supinating the palm engages the biceps - try it, your bicep will shorten. I'd have thought isolating brachialis holding a dumbell in hammer position is better (ie palm facing sideways, 90* to the floor not parallel to it). It's what I've done in the past.