How Do Your Biceps and Triceps Raise Your Arm?
The biceps and triceps muscles are used to bend and extend the arm, while the deltoids are the muscles that lift the arm. When the bicep muscle contracts or flexes, it bends the forearm toward the shoulder. When the tricep flexes, it extends the forearm, straightening the arm. The bicep and tricep do not contract simultaneously. When one muscle is contracted, the other relaxes.