When a bicep contracts it pulls on tendons causing the arm to bend at the elbow.
When the bicep contracts the triceps relax
it contracts
The Triceps extend (Stretch out) as the biceps contract.
Biceps Biceps
relax
When you bend your arm at the elbow and feel your biceps your upper arm muscle contracts.👏👏
When the biceps contracts the triceps relaxes slowly. It happens when your arm is bent.
It either expands or contracts depending on which way you're bending your elbow.
When a muscle contracts, it shortens in length.
The muscle that causes a joint to straighten when it contracts are the extensor muscles. These include the triceps that work with the biceps to extend the arm.
The agonist to the biceps muscle is the triceps brachii. While the biceps brachii is responsible for flexing the elbow and supinating the forearm, the triceps brachii acts as the antagonist by extending the elbow. During movements such as arm extension, the triceps contracts while the biceps relaxes.
The Biceps brachii muscle. We just call it the biceps, though. (Pronounced bye-seps) To straighten the arm again, the triceps muscle is contracted - which lies 'underneath' the upper arm.