When we think of muscles in the arm, we often think of biceps and triceps. However, there are many other muscles involved in arm movement, including the brachioradialis, pronator teres, and supinator muscles. So, which muscle contracts when the arm is straightened?
The muscle responsible for straightening the arm is the triceps brachii. This muscle is located on the back of the upper arm and is responsible for extending the elbow joint. When we straighten our arm, the triceps contracts and pulls the arm straight.
The triceps brachii is the largest muscle in the arm and is made up of three heads: the long head, the lateral head, and the medial head. Each of these heads attaches to different parts of the upper arm bone and works together to extend the elbow joint.
When we perform exercises such as push-ups, bench press, or tricep extensions, we are targeting the triceps brachii muscle. Strengthening this muscle can improve our overall arm strength and help with daily activities such as lifting and carrying.
It is important to note that while the triceps brachii is responsible for straightening the arm, other muscles also play a role in arm movement. In fact, the biceps brachii muscle is responsible for flexing the elbow joint and is often considered a counterpart to the triceps. Additionally, the shoulder and forearm muscles also contribute to arm movement.
In conclusion, the muscle that contracts when the arm is straightened is the triceps brachii. While other muscles also play a role in arm movement, strengthening the triceps can improve overall arm strength and function.