When you bend your elbow, the biceps muscle contracts. At the same time the antagonist muscle, that is the triceps muscle relaxes in synchronized manner. Vise verse action take place, when you straighten the arm at the elbow. Triceps contracts and biceps relaxes.
The muscle that causes a joint to straighten when it contracts is called an extensor. Extensors work by increasing the angle between the bones at a joint, allowing for actions such as straightening the arm or leg. For example, the triceps muscle is an extensor that straightens the elbow joint when it contracts.
Antagonistic muscles work together in pairs to produce movement in opposite directions around a joint. When one muscle contracts, its counterpart relaxes, allowing for coordinated and smooth movement. This arrangement helps stabilize the joint and ensures efficient movement. An example is the biceps and triceps in the arm, which work together to bend and straighten the elbow.
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.
While one muscle contracts, the other muscle in the pair returns to its original length. The main muscle that bends your upper arm is called the Biceps brachii. The action is called flexion at the elbow. This muscle is on the "front" of the arm. The muscle that acts against this one is called the Triceps brachii. Its' action is extension at the elbow. This muscle is on the "back" of the arm. See the link below:
A muscle that causes a joint to bend when it contracts is called a flexor. Flexor muscles, such as the biceps brachii in the upper arm, work by shortening and pulling on the bones to decrease the angle at a joint, facilitating movements like bending the elbow. In contrast, extensors are muscles that increase the angle at a joint.
FLEXORSBiceps brachia- Primarily forearm supination, but also functions in elbow flexion, shoulder flexion, and shoulder adductionChoracobrachialis- Shoulder flexion, shoulder adductionBrachialis- Elbow flexionEXTENSORSTriceps Brachii- Powers elbow extension
The primary muscle that controls elbow movement is the biceps brachii, which flexes the elbow when contracted. Additionally, the triceps brachii is responsible for extending the elbow. These muscles work in coordination to facilitate various movements of the arm.
The muscles that cause joints to bend are called flexors. These muscles contract to decrease the angle between two body parts, facilitating movements like bending the elbow or knee. In contrast, muscles that straighten joints are known as extensors. Together, flexors and extensors work to enable a wide range of motion in the body.
Skeletal muscles are arranged as opposing pairs because, although they can shorten themselves by contracting, they have to be stretched back to their former length by other muscles. An example of opposing muscles is in the arm, where the biceps and triceps have opposite actions. As one muscle shortens, the other is stretched. The biceps contracts to bend the arm at the elbow while the triceps stretches. To straighten the elbow joint, the triceps contracts, while the biceps stretches.
When you make a muscle in your arm, you are flexing your biceps brachii, which is located in the front of your upper arm. This muscle contracts to bend your elbow and bring your forearm closer to your shoulder. Additionally, the triceps muscle, located at the back of your upper arm, relaxes to allow this movement. Together, these muscles work to enable various arm movements.
Skeletal muscles only pull in one direction. For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its counterpart then contracts and pulls in the opposite direction to straighten the joint out again.