What’s the difference between a bicep curl and a pull-up? They both hit the same muscle, the bicep. There are several differences, such a bicep curl is an isolation movement and the pull-up is a compound movement; the pull-up involves more muscles, such as the lats. But I would like to focus on one very specific difference in how the bicep works during the movement.
The movement in a bicep curl brings the insertion closer to the origin. The pull-up brings the origin toward the insertion. Let me show you what this means, and why it’s so important.
Every muscle has two or more attachment sites, the places where the muscle attaches to bone. One of these attachments is called the origin, and the other is called the insertion. Think of the origin as being where the muscle is the biggest. There is a very strong attachment to the bone. The insertion is kind of like an offshoot of the origin.
When a muscle tightens, or contracts, it can do 1 of 3 things. It can bring the insertion closer to the origin, it can bring the origin closer to the insertion, or it can do both at the same time. The bicep runs from the shoulder to the elbow, down the front of the arm. The shoulder attachment is the origin, the elbow attachment is the insertion.
So if you do a bicep curl, you’re bringing the insertion (the smaller connection) toward the origin (the bigger connection). When you do a pull-up, you’re bringing the larger connection at the shoulder toward the smaller connection at the elbow.
Why is this important? When you start an exercise program, you want to begin with basic movements and progress to more demanding movements. A bicep curl is a standard origin-insertion exercise. A pull-up is a reverse origin-insertion exercise (and it’s much harder). Initially you may want to incorporate bicep curls into your program, but after you develop some strength pull-ups will be a better option.
Here are some other standard exercises and their corresponding reverse origin-insertion counterparts:
Supine Leg Raises and Full Sit-Up. Tricep Extension and Push-Ups. Hands and Knees Donkey Kicks and Superman. Click here to see pictures of these exercises.
Changing the origin and insertion is one concept that you can play with to add unlimited progression to your fitness program.
For a practical demonstration of this principle, give us a call to redeem your complimentary Core Baseline workout. This workout includes 30 exercises, and gradually progresses from easy to difficult (from standard origin-insertion to reverse origin-insertion). It is different than any personal training program you’ve likely been through. We’re conveniently located in the Willow Glen area of San Jose. Give us a call today: (408) 883-4442.
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