Throwin' it back to one of our most unforgettable duos of ALL TIME...remember when @__CARTERDANE met @SeanZevran? 🤯😩 Take a moment to relive some of the jackhammering, then download Carter & Sean's entire CB masterpiece 👉🔗https://t.co/8woFn0BSmZ
A look at the muscles at work during arm flexion and extension.
Flexion activates the biceps brachii, brachialis, brachioradialis, extensor carpi radialis longus, and extensor carpi radialis brevis, while extension engages the triceps brachii and anconeus.