The bicep has three main functions: arm flexion (the curl), forearm supination (which is why I prefer a straight bar) and shoulder flexion (rotating the shoulder up, lifting the arm up). So finishing the curl with a shoulder flexion makes sense.
But in the past it always felt like I was losing the contraction when I did that. Why? Because when I did the shoulder flexion I'd let the shoulders go up and would let the traps kick in. You want the shoulders to rotate up, not to be lifted up. So you must work extra hard to keep the shoulder blades retracted and down.
Do not let the traps fire up. If you don't feel a stronger biceps contraction you aren't doing it right and need to practice.
The Smith machine is used by bodybuilders, strongmen, and powerlifters. And they're bigger and stronger than you, hater. Maybe it's time you learn to use it right. Here's how.
Prior to the early 90's, hardly anyone used scientific references to support their notions – not in real life and certainly not in the magazines. You just said what you believed and most of the time no one questioned you.
For several years, I was the Watson to Strength Coach Charles Poliquin's Sherlock Holmes. I chronicled his theories, revelations and discoveries. I like to think I played a small part in his success but in all probability, guys like Charles don't need any help; they get famous all on their own.