Chapter 11

DUE: SUNDAY NOVEMBER 3RD AT 8PM EST

Alfredo received three free personal training sessions when he joined the gym a couple months ago. When he first met the trainer, Jessica, he told her he joined the gym mostly to try to increase his arm strength and get better definition in his arm muscles. Jessica proceeded to teach him some basic arm exercises and outlined a schedule for his workouts over the next couple weeks. She instructed him to rotate between three different upper arm exercises using dumbbells.

In the first exercise, he gripped the dumbbells with his hands supinated (underhand grip) and flexed his elbows to lift the weights. Alfredo recognized this “arm curl” exercise. In the second exercise, Jessica told him to hold the dumbbells with a semi-supinated grip (thumbs pointed ventrally) and again flex his elbows to lift the weights. She told him this was sometimes called a hammer curl. In the final exercise, Jessica had Alfredo grip the dumbbells with his hands pronated (overhand grip), and again he flexed his elbows to lift the weights.

After learning these exercises, Alfredo commented, “What’s the point of these three different exercises? It seems like they’re all basically the same. I know from my A&P class that the biceps brachii does elbow flexion, so why do I need all these variations when I’m only working out that one muscle?”

Jessica smiled at him when she heard this and said, “I think you might need to check your A&P book before your test on the muscle system!”

Questions

1. In what ways do you think Alfredo’s knowledge of the muscle system is incomplete?

2. Think about the arrangements of the bones in the three exercises Jessica taught Alfredo and the insertions of the muscles in the arm. Which muscle do you think each exercise is designed to target?